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Glenwood Canyon geosynthetic-reinforced shredded tire retaining wall

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Title:
Glenwood Canyon geosynthetic-reinforced shredded tire retaining wall
Creator:
Yu, Sung-Hsing
Place of Publication:
Denver, CO
Publisher:
University of Colorado Denver
Publication Date:
Language:
English
Physical Description:
111 leaves : illustrations ; 28 cm

Subjects

Subjects / Keywords:
Retaining walls -- Colorado -- Glenwood Canyon ( lcsh )
Geosynthetics -- Colorado -- Glenwood Canyon ( lcsh )
Waste tires -- Colorado -- Glenwood Canyon ( lcsh )
Geosynthetics ( fast )
Retaining walls ( fast )
Waste tires ( fast )
Colorado -- Glenwood Canyon ( fast )
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bibliography ( marcgt )
theses ( marcgt )
non-fiction ( marcgt )

Notes

Bibliography:
Includes bibliographical references (leaves 110-111).
Thesis:
Civil engineering
General Note:
Department of Civil Engineering
Statement of Responsibility:
by Sung-Hsing Yu.

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|University of Colorado Denver
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|Auraria Library
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All applicable rights reserved by the source institution and holding location.
Resource Identifier:
47813830 ( OCLC )
ocm47813830
Classification:
LD1190.E53 2001m .Y8 ( lcc )

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Full Text
GLENWOOD CANYON GEOSYNTHETIC-REINFORCED
SHREDDED TIRE RETAINING WALL
Sung-Hsing Yu
B.S., National Taiwan University, 1990
A thesis submitted to the
University of Colorado at Denver
in partial fulfillment
of the requirement for the degree of
Master of Science
Civil Engineering
by
2001


This thesis for the Master of Science
degree by
Sung-Hsing Yu
has been approved
by
Dati
I8.2od)


Yu, Sung-Hsing (M.S., Civil Engineering)
Glenwood Canyon Geosynthetic-reinforced Shredded Tire Retaining Wall
Thesis directed by Professor Jonathan T.H. Wu
ABSTRACT
In October 1994, the Colorado Department of Transportation constructed a
geosynthetic-reinforced retaining wall using shredded tires as backfill. The retaining
wall was constructed over a landslide area along Interstate Highway-70 near
Glenwood Canyon, Colorado. The retaining wall was constructed in 7 tiers with a
total height of 21 m (70 ft). This was, and still is, the highest tire-shred retaining wall
in the world. The wall was instrumented with survey targets and horizontal
inclinometers at strategic locations to monitor its performance during and after
construction.
A study was undertaken to investigate the long-term performance the
geosynthetic-reinforced retaining wall. The study was conducted by the finite
element method of analysis using a computer model, GREWS. The computer model
is capable of analyzing the time-dependent performance of an earth structure due to
body forces and externally applied loads. Prior to conducting the analysis, the
in


deformation properties of the shredded tires were investigated. One-dimensional
compression tests and direct shear tests were performed using a specially designed
apparatus that can accommodate a specimen size of 76 cm by 76 cm by 61 cm (30 in.
by 30 in. by 24 in).
The measured properties of the shredded tires were used as input to compute
the deformed configuration of the wall. The computed deformation was compared
with the measured deformation. Very good agreement was observed. The analytical
model was then employed to predict the long-term performance of the retaining wall.
The predicted maximum displacement over 75 years was found to be on the order of
9.1 ft (2.8 m), occurred near the top tier. The retaining wall was subsequently
demolished following self-combustion occurred in October 1995. Further research
will be needed for future usage of shredded tires in the construction of retaining
walls.
This abstract accurately represents the content of the candidates thesis. I recommend
its publication.
IV


ACKNOWLEDGEMENT
I would like to thank Professor Jonathan Wu for his unlimited guidance and
encouragement throughout my academic and research program. Also, I would like to
thank Colorado Department of Transportation for providing all the materials,
equipment and information.
Finally, I would like to thank my parents, my wife, and daughters for their
unfaltering understanding and support through my study.


CONTENTS
Figures............................................................... ix
Tables ............................................................... xi
Chapter
1. Introduction..................................................... 1
1.1 Problem Statement................................................ 1
1.2 Objectives....................................................... 2
1.3 Method of Research............................................... 2
2. The Glenwood Canyon Shredded Tire Test Wall..................... 4
2.1 Overview......................................................... 4
2.2 Pre-Construction Test: Oxford Test Wall.......................... 7
2.3 Design and Construction of Glenwood Canyon Test Wall............ 10
2.4 Monitoring of Wall Performance.................................. 12
2.4.1 Survey Points................................................... 12
2.4.2 Horizontal Inclinometers........................................ 14
3. One-dimensional Compression Test and Direct Shear Test.......... 17
3.1 Test Material................................................... 17
3.2 One-dimensional Compression Test................................ 17
3.2.1 Test Apparatus.................................................. 17
vi


3.2.1.1 Test Box........................................................ 20
3.2.1.2 Loading Mechanism............................................... 20
3.2.2 Measurement and Data Acquisition System......................... 23
3.2.3 Sample Preparation and Test Procedure........................... 23
3.2.4 Results and Discussions......................................... 26
3.3 Direct Shear Test................................................ 29
3.3.1 Test Apparatus................................................... 29
3.3.2 Measurement and Data Acquisition System.......................... 29
3.3.3 Sample Preparation and Test Procedure............................ 29
3.3.4 Results and Discussions.......................................... 33
4. Finite Element Analysis.......................................... 37
4.1 Description of GREWS............................................. 37
4.1.1 Element Types of GREWS........................................... 39
4.1.2 Soil Models...................................................... 39
4.1.3 Beam and Bar Models.............................................. 42
4.1.4 Interface Model.................................................. 42
4.2 Determination of Material Parameters for Tire Chips.............. 43
4.2.1 Material Parameters of Tire Chips................................ 43
4.2.2 Material Parameters of Foundation Soil........................... 47
4.2.3 Material Parameters of Facing and Geogrid Reinforcement.......... 50
vii


4.2.4 Material Parameters of Soil-Tire Chips Interface.................. 54
4.3 Finite Element Analysis of the One-dimensional Compression Test. 55
4.4 Finite Element Analysis of the Glenwood Canyon Test Wall.......... 59
4.4.1 Comparison of Measured Results and Finite Element Analysis Results 61
4.4.2 Predicted Wall Movement of Glenwood Canyon Test Wall.............. 61
5. Summary and Conclusions........................................... 64
5.1 Summary........................................................... 64
5.2 Findings and Conclusions.......................................... 65
Appendix
A. Survey and Inclinometer Data.................................. 68
B. Data of One-dimensional Compression Test and Direct Test...... 81
C. Input Data of Finite Element Analysis for One-dimensional
Compression Test............................................... 87
D. Input Finite Element Analysis Data for Glenwood Canyon Test
Wall........................................................... 90
References.............................................................110
vm
i
I


FIGURES
Figure
2.1 The Site Appearance Before Construction of the Glenwood Canyon
Shredded Tire Test Wall............................................. 5
2.2 The Appearance of the Glenwood Canyon Test Wall after Construction 6
2.3 Design Configuration of the Oxford Test Wall........................ 8
2.4 The Appearance of the Oxford Test Wall.............................. 9
2.5 The Design Configuration of the Glenwood Canyon Test Wall........ 11
2.6 Deformed Configuration of the Test Wall............................ 13
2.7 Measured Vertical Displacement from Inclinometer Tube A, 3 Months
after Construction............................................... 15
2.8 Measured Vertical Displacement from Inclinometer Tube B, 3 Months
after Construction................................................. 16
3.1 Various Lengths and Shapes of Tire Chips........................... 18
3.2 Overall Schematic of One-dimensional Compression Test Apparatus.. 19
3.3 The Test Box....................................................... 21
3.4 Pressure Gauges.................................................... 22
3.5 The Installation of LVDTs.......................................... 24
3.6 Stress-Strain-Time Curve for the Tire Chips........................ 27


3.7 Strain Rate vs. Log (Time) Curve for the Tire Chips............ 28
3.8 Overall Schematic of Direct Shear Test Apparatus............... 31
3.9 The Test Setup for (a) One-dimensional Compression Test and (b)
Direct Shear Test.............................................. 32
3.10 Shear Stress vs. Normal Stress................................. 36
4.1 Vertical Strain vs. Logarithm of Time in One-dimensional Compression
Test........................................................... 51
4.2 Vertical Strain vs. Square Root of Time in One-dimensional
Compression Test............................................... 52
4.3 Tire Blocks.................................................... 53
4.4 The Finite Element Mesh for One-dimensional Compression Test.. 57
4.5 The Comparison of the Creep Behavior of Tire Chips from GREWS
Analysis and One-dimensional Compression Test.................. 58
4.6 Finite Element Mesh for Glenwood Canyon Test Wall.............. 60
4.7 Comparison of Measured and Finite Element Analysis Result...... 62
4.8 Predicted Wall Movement after 75 Years of Glenwood Canyon Test
Wall........................................................... 63
x


TABLES
Table
3.1 Data for the Dial Gauge Vertical Stress and Actual Vertical Stress at
Failure............................................................ 34
3.2 The Vertical and Horizontal Stresses at Failure Using Corrected Areas 35
4.1 Material Parameters for Sekiguchi-Ohta Model....................... 49
4.2 Properties of Foundation Soil...................................... 49
4.3 Material Parameters for Foundation Soil............................ 49
4.4 Material Parameters for Beam Elements.............................. 50
4.5 The Input Geogrid Parameters for Bar Elements...................... 50
4.6 The Input of the Interface Parameters.............................. 54
4.7 The Adjusted Input Parameters for Tire Chips....................... 56
xi


1. Introduction
1.1 Problem Statement
Over two billion waste tires are sitting in stockpiles across the U.S., and more
than 240 million waste tires, are being discarded each year (Maine Department of
Environmental Protection (DEP), 1989; Eaton, et al., 1991; Stark and Korte, 1988).
Disposal of these waste tires has become an acute environmental problem because of
its fast increasing volume.
Although tires are classified as a nonhazardous waste, their disposal presents
fire hazards and pollution problems. Serious tire fires have been reported in Texas,
Virginia, Washington, and Florida (Maine DEP, 1989). These fires were difficult to
extinguish and typically lasted several months. They also produced toxic air and
toxic oil by products.
In mid-1960s, an alternative disposal method for waste tires began in the
asphalt pavement construction. Ground tire rubber was blended with hot liquid
asphalt as highway pavement material (Eaton, et al., 1991).
In recent years, waste tires are cut into chips (referred to as shredded tires or
tire chips) of various sizes to reduce their disposal volume. Shredded tires have
many desirable characteristics in engineering applications. They are durable,
1


lightweight, and free draining; therefore, they can be a viable substitute for soil in the
construction of earth structures such as retaining walls. Only recently have attempts
been made by researchers in Maine and Wisconsin to use shredded tires in retaining
wall construction (Maine DEP, 1989).
In October 1994, the Colorado Department of Transportation constructed a 21
m (70 ft) high retaining wall using shredded tires as backfill. The retaining wall was
constructed over a landslide area and is located in Glenwood Canyon, Colorado along
Interstate Highway-70. To the authors knowledge, this is the highest tire-shred
retaining wall in the world.
1.2 Objectives
The objectives of this study were two-fold. The first objective was to
determine engineering properties of shredded tires. The second objective was to
predict the long-term performance of the Glenwood Canyon tire chip test wall.
1.3 Method of Research
To predict the long-term performance of the Glenwood Canyon tire chip test
wall, the finite element method of analysis was employed. A computer program,
GREWS (Geosynthetic-REinforced Wall and Slopes), was used for the analysis (Wu,
et al., 1994). The program is capable of simulating long-term creep of the tire chips
2


and determining the long-term performance of the test wall.
Direct shear tests were performed on tire chips. Since the chips are fairly
large in size (nominal width = 2 in.), a large direct shear apparatus was manufactured
to conduct the tests. The test box was also used to conduct a one-dimensional long-
term compression test for the tire chips.
3


2. The Glenwood Canyon Shredded Tire Test Wall
This chapter gives a brief overview of the Glenwood Canyon shredded tire
wall and describes the design and construction of test wall. In addition, the
monitoring system, including the survey points and horizontal inclinometers, which
were installed during construction, is presented.
2.1 Overview
In 1930s, two lanes of the U.S. Highway 6 was built through the Glenwood
Canyon, Colorado. The construction resulted in a number of erosional scars along
this highway. In the 1980s, the two-lane highway was expanded into four lands,
becoming part of Interstate Highway-70. There was an agreement between the
Colorado Department of Highways (CDOH) and the Environmental and Citizen
Group prior to the reconstruction of the road to repair the erosional scars (Bell, et al.,
1983).
The instabilities of the scars near the Hanging Lake rest station, about 12
miles east of Glenwood Springs, have been a concern for highway safety. In the early
1990s, the CDOH began to remediate the slopes. After evaluating alternatives, the
CDOH decided to employ a lightweight fill retaining wall system with a sloping top
4


surface cover the scars.
The Glenwood Canyon shredded tire test wall was constructed from October
1994 to February 1995. Figure 2.1 shows the appearance of the Glenwood Canyon
test wall site before construction. Figure 2.2 shows the Glenwood Canyon test wall
after construction.
Figure 2.1 The Site Appearance before Construction of the Glenwood Canyon
Shredded Tire Test Wall
5


Figure 2.2 The Appearance of the Glenwood Canyon Test Wall after Construction
6


2.2 Pre-construction Test: Oxford Test Wall
In June 1994, CDOT constructed a small tire chip GRS test wall prior to
construction of the Glenwood Canyon wall. This test wall was referred to as the
Oxford test wall. Figure 2.3 depicts the design configuration of the Oxford test wall.
This test wall had one tier, which was about 3 m (10 ft) tall. The area was
approximately 20 m (60 ft) long and 6 m (18 ft) high. The wall face consisted of
compressed tire blocks, which weigh about 1/3 of concrete. The backfill was large
size shredded tires. The shredded tire backfill is about 1/4 the weight of soil. No
anchors were used, and the backfill was reinforced with layers Tensar 1400 geogrid
at 60 cm (2 ft) vertical spacing. Figure 2.4 shows the appearance of the Oxford test
wall.
The survey points were installed to monitor the performance of the test wall
after construction. A total of 20 survey targets were installed. The survey targets
were mounted on the wall face in a somewhat uniformly distributed pattern.
7


I
I
I
Front View
Instrumentation Layout number points are survey reflectors
Side View
Figure 2.3 Design Configuration of the Oxford Test Wall
I
I
8


Figure 2.4 The Appearance of the Oxford Test Wall
9


2.3 Design and Construction of Glenwood Canyon Test Wall
The engineering design for the Glenwood Canyon test wall was performed by
John Kliethermes Jr., and constructed by Service Engineering, Inc.
This test wall had 7 tiers, with each tier about 3 m (10 ft) tall. The area was
approximately 100 m (300 ft) long and 30 m (90 ft) high. The wall face consisted of
compressed tire blocks and the backfill was shredded tires (5 cm (2 in.) tire chips) in
the top 5 tiers. The backfill in the bottom 2 tiers was on site soils. No anchors back
into the hillside were used, and the backfill was reinforced with layers Tensar 1400
geogrid at 60 cm (2 ft) vertical spacing. Figure 2.5 depicts the design configuration
of the Glenwood Canyon test wall.
The total estimated cost for this project was approximately $750,000. This is
about 1/3 the cost of a traditional concrete retaining solution which would require
long soil anchors for stability due to the weights of concrete and soil backfill (Barrett,
1995).
10


Figure 2.5 The Design Configuration of the Glenwood Canyon Test Wall


2.4 Monitoring of Wall Performance
The survey points and inclinometers were installed to monitor the
performance of the test wall during and after construction. A total of 112 survey
targets and four horizontal inclinometers were installed. The survey targets were
mounted on the wall face in a somewhat uniformly distributed pattern. The
inclinometers were embedded at the bottom of the 3rd and 5th tiers.
2.4.1 Survey Points
Figure 2.6 shows the displacement profile near the center section of the test
wall 7 months after construction as measured by the survey points. The maximum
wall displacement was about 138 cm (4.5 ft) outward and 109 cm (3.6 ft) downward
and occurred at the top after sixth tier. The measurement data of survey points are
presented in Appendix A.
12


Figure 2.6 Deformed Configuration of the Test Wall


2.4.2 Horizontal Inclinometers
Figures 2.7 and 2.8 show the result of inclinometer tubes A and B,
respectively. Inclinometer tube A was located at the center section of the third tier,
and inclinometer tube B, also installed in the third tier, was located at 5 m (15 ft) to
the right of tube A. The last set of data was taken 3 months after construction due to
a very large displacement, which bent the tube very significantly. The largest
displacement 3 month after construction was about 73 cm (29 in.) in tube A, and 59
cm (23 in.) in tube B, both occurred near wall face. The displacement decreased
approximately linearly toward the back of the wall.
Inclinometer tubes C and D were located at the fifth tier. The last set of data
was taken about 1 month before the end of construction. Because of large
displacements tube C and D deformed substantially, it was not possible to insert the
inclinometer probe in the tube for measurement. The measurement data of the
inclinometers are also shown in Appendix A.
14


Vertical Displacement (cm)
Tier 3 Center Section
Distance from Wall Face (cm)
Figure 2.7 Measured Vertical Displacement from Inclinometer Tube A, 3 Months
after Construction
15


Tier 3,5 meter to the Right of Center Section
Distance from Wall Face (cm)
Figure 2.8 Measured Vertical Displacement from Inclinometer Tube B, 3 Months
after Construction
16


3. One-dimensional Compression Test and Direct Shear Test
A one-dimensional compression test was conducted to determine time-
dependent deformation of the tire chips. Direct shear tests were conducted to
determine the friction characteristics of the tire chips. The tests were conducted
using a test apparatus designed and manufactured by the Colorado Transportation
Institute (CTI).
3.1 Test Material
The tire chip tested is referred to as 5 cm (2 in.) tire chip, implying that the
maximum width of the tire chip is 5 cm (2 in.). The length of the chips typically
varies between 2.5 cm (1 in.) and 15 cm (6 in.). Typical thickness is 0.8 cm (0.3 in.),
with some containing a steel belt sandwiched at the middle. Figure 3.1 shows
various lengths and shapes of the tire chips.
3.2 One-Dimensional Compression Test
3.2.1 Test Apparatus
As shown in Figure 3.2, the test apparatus consists of a test box, a pulley-
frame arrangement, and a data acquisition system. The pulley-frame arrangement
17


was used to hoist the components of the test apparatus during assembly and
disassembly.
Figure 3.1 Various Lengths and Shapes of Tire Chips
18


Scale
VO
Figure 3.2 Overall Schematic of One-dimensional Compression Test Apparatus


3.2.1.1 Test Box
The test box for the one-dimensional compression test consists of a lower
box, an upper box, a sliding block, and a top cap, as is shown in Figure 3.3. The top
box is 76 cm (30 in.) in length, 76 cm (30 in.) in width, and 41 cm (16 in.) in height,
the bottom box has the same length and width as the top box but its height is 20 cm
(8 in.).
The side walls in the interior of the test box were lubricated to minimize side
wall friction upon load application. The lubrication was achieved by placing a latex
membrane between the internal side wall of the test box and the test material (i.e., tire
chips). A uniform layer of silicon grease was applied to the surface of internal side
walls before placement of the membrane. Such a technique has been shown to
reduce the friction angle to 1 degree (Tatsuoka, et al., 1984).
3.2.1.2 Loading Mechanism
The vertical load was applied by pneumatic pressure applied to the top surface
of the tire chips. The pressure was exerted by using an air bladder which was fitted
inside the upper box between the top cap and the sliding block (see Figure 3.3). Three
gauges were used to monitor the air pressure (see Figure 3.4).
20


Sliding Block
21


I
Figure 3.4 Pressure Gauges
22


3.2.2 Measurement and Data Acquisition System
Two Linear Voltage Displacement Transducers (LVDT) were used to
measure the compression of the tire chips. The sensing rod of the LVDT was in
contact with a blade extruding through a narrow slot outside of the test box from the
sliding block (see Figure 3.5).
A personal computer equipped with an electronic board was connected to the
LVDT to record the digital data which were converted from voltages read by the
LVDT through an electronic board. The computer program used to collect the data is
called KEITH. The data acquisition system has 5 channels which could be connected
to LVDTs or load cells. In the one-dimensional compression tests, readings were
taken at 10-minute intervals.
3.2.3 Sample Preparation and Testing Procedure
The procedure of sample preparation and testing can be described by the
following steps:
1. Place the upper box directly over the lower box and securely clamp the 2
boxes.
2. Lubricate side walls: Apply a thin layer of Shin-Etsu Silicone grease on
internal side walls by using a brush.
23


LVDT
Figure 3.5 The Installation of LVDTs
24


3. Place a layer of latex membrane on the side wall: The size of membrane
needs to be slightly larger than the side wall to prevent direct contact of the
tire chips with the side wall.
4. Place the tire chips inside the text box: Separate a total weight of tire chips of
179.8 kg (396 lbs) into 3 equal parts. Each part of the tire chips was placed
inside the test box and compacted to the desired density. It was found that
compacting tire chips was very different from compacting soils. After
removal of the compaction load, the tire chips tend to rebound. The modified
Proctor with 4.5 kg (10 lbs) hammer was not efficient for compaction,
because of the elasticity of the tire chips. It was found that a person jumping
up and down on the surface with the help of a metal rod poking the chips,
produced fairly efficient compaction. After 3 layers of compaction, the total
height of the test samples in the test box was 48.3 cm (19 in.) and the unit
weight of the tire chips was 6.3 kN/m3 (40 pcf).
5. Set the sliding block on the top surface of the tire chips.
6. Install the air bladder on top of the sliding block.
7. Assemble the top cap and lock off the steel posts to secure the boxes.
8. Install the LVDT as described in Section 3.2.2.
9. Install the pressure supply system and data acquisition system.
10. Begin the test: The pressure in the air bladder was applied in four increments
25


2
over a period of four days. An equal increment of 13.8 kN/m (2.0 psi) was
2
applied in the first 3 days. On the fourth day, an increment of 10.3 kN/m
(1.5 psi) was applied, which brought the total pressure to 51,7kN/m (7.5 psi).
Thereafter, the pressure was maintained at 51.7kN/m (7.5 psi) for 42 days.
Readings of compression were taken at 10 minutes intervals for the first 7
days. Thereafter, the interval of reading was 1 day.
3.2.4 Results and Discussions
The purpose of the one-dimensional compression test was to determine the
load-deformation behavior of the tire chips which was needed for finite element
analysis. In addition, a long term compressibility test was performed to determine
creep characteristics of the tire chips under a sustained load. The test data presented
in this chapter were tabulated in Appendix B.
Figure 3.6 shows the relationships of strain, elapsed time, and vertical stress.
The strain is calculated based on the vertical displacements as the average of the 2
LVDT measurements. The strain-time curve shows the creep behavior under a
vertical stress of 51.7 kN/m (7.5 psi). It should be noted that the deformation
continued to occur when the test was terminated.
26




Figure 3.7 illustrates the strain rate versus logarithm of time. The curve
shows that the strain rate decreases with time at decreasing rate. At the end the test
period of 60,000 minutes (42 days), the strain rate was 0.2964x1 O'5 /min.
One-dimensional Compression Test
log (time) (min)
Figure 3.7 Strain Rate vs. Log (Time) Curve for the Tire Chips
28


3.3 Direct Shear Test
3.3.1 Test Apparatus
The test apparatus used in direct shear tests was the same as that used in the
one-dimensional compression test, as described in Section 3.2.1, except that:
The lower box was attached to a hydraulic jack and was allowed to move
horizontally relative to the upper box (see Figure 3.8).
A load cell was mounted to measure the horizontal force transferred to the
upper box (see Figure 3.8).
3.3.2 Measurement and Data Acquisition System
The measurement and data acquisition system was the same as that described
in Section 3.2.2 for the one-dimensional compression test, except that a LVDT was
added to measure horizontal displacement of the lower box as the shear force was
being applied.
3.3.3 Sample Preparation and Test Procedure
Per AASHTO designation T236-84 Direct Shear Test of Soil Under
Consolidated Drained Conditions, the width of direct shear box should be at least
twice as the height, and the height of the box should be at least six times the soil
29


grain size (AASHTO, 1986). For the 5 cm (2 in.) tire chips, the size of test box is
deemed adequate.
Sample preparation and data acquisition followed essentially the same
procedure as that described in Section 3.2.3. The testing procedure can be described
by the following steps:
1. A load cell was set to recording the horizontal force. The hydraulic jack was
set to push the lower box at a constant displacement rate of 2.5 cm/min (1
in./min) speed.
2. Three different vertical stresses were applied to the specimen. The first test
y
was conducted under 34.5 kN/m (5 psi) of vertical stress, the second at 51.7
kN/m (7.5 psi) vertical stress, and the third at 69.0 kN/m (10 psi) vertical
stress.
3. Remove the clamps which were employed to fixed the upper box and lower
box during preparation of the sample, then start the test. A comparison of the
test setup between the one-dimensional compression test and direct shear test
is shown in Figure 3.9.
4. The tests were terminated when the horizontal movement reached 15.2 cm (6
in.) (i.e., 20% of the length of the sheer box).
30


Scale
0 0.5 1 m

BHBBBSBnanBBB9R9BnSn&HHRBCtiJJ
Steel Post Hydraulic Jack ^ata Acquisition System
Figure 3.8 Overall Schematic
of Direct Shear Test Apparatus


Clamp

Upper Box
Lower Box
n
Clamp
(a)
Upper Box
(Affixed)
Lower Box

Shear Force
(b)
Figure 3.9 The Test Setup for (a) One-dimensional Compression Test and (b) Direct
Shear Test
32


3.3.4 Results and Discussions
The AASHTO (1986) designation T236-84 Direct Shear Test of Soil Under
Consolidated Drained Conditions specifies that failure occurs when the horizontal
displacement reaches to 10% of the length of box. This specification is for those
direct shear tests that cannot achieve a peak shear stress such as tire chips.
The vertical stress was applied by pneumatic pressure which had been
calibrated by Mr. Ruckman of CDOT. The calibration equation is:
cta= 0.85 ctd + 437.1 (3.1)
a
where cta= Calibrated applied pressure, N/m
2
ctd= Applied pressure (from pressure gauge), N/m
Table 3.1 shows the relationship between the applied and calibrated pressures
used in the tests.
33


Table 3.1 Data for the Dial Gauge Vertical Stress and Actual Vertical Stress at
Failure
Applied Pressure (from Pressure gauge) gd (kN/m2) Calibrated applied pressure ga (kN/m2)
34.5 (5 psi) 29.7 (4.3 psi)
51.7 (7.5 psi) 44.4 (6.4 psi)
69.0 (10 psi) 59.0 (8.6 psi)
Note: ga= 0.85 gd + 437.1 (Units: N/m2)
The contact area between upper and lower boxes decreases during the test.
To determine the stresses in the soil, the actual contact area (corrected area) should
be used. The corrected area can be calculated as:
Ac Wx(L 2d) (3.2)
In which, W is the width of the shear box, L is the length of the shear box, and d is
the displacement. Using the corrected areas, the vertical and horizontal stress can be
calculated, as shown in Table 3.2. It is noted that the horizontal stresses were
determined as the displacement reached 10% of the box length per AASHTO T236-
84.
34


Table 3.2 The Vertical and Horizontal Stresses at Failure Using Corrected Areas.
Corrected Area Ac (m2) Vertical Stress od (kN/m2) Horizontal Stress x (kN/m2)
0.465 (720 in.2) 37.2 (5.39 psi) 21.1 (3.06 psi)
0.465 (720 in.2) 55.5 (8.05 psi) 34.9 (5.06 psi)
0.465 (720 in.2) 73.8(10.7 psi) 42.7 (6.19 psi)
Figure 3.10 shows the Mohr-Coulomb failure envelope. The strength
parameters were: internal friction angle, (j) = 30.5 and cohesion, C = 0.2 kN/m (4.4
psf). Humphrey, et al (1992) reported strength parameters of various tire chip in the
rangeof: <(>= 19to25andC = 7.66kN/m2(160psf)to 11.49kN/m2(240psf). The
tire chips in their study was generally smaller in size, and the test apparatus measured
was 30 cm by 30 cm (12 in. by 12 in.).
35


Direct Shear Test
2
Normal Stress (kN/m )
Figure 3.10 Shear Stress vs. Normal Stress
36


4. Finite Element Analysis
A finite element computer code, GREWS, was selected for analyzing
performance of the Glen wood Canyon tire shred wall. The computer program
was developed by Wu, et al., (1994) on behalf of CTI and CDOT. This chapter
describes the analytical model GREWS, determination of material parameters,
analysis of one-dimensional compression tests, and condition analysis of the
Glenwood Canyon test wall.
4.1 Description of GREWS
GREWS is a comprehensive analysis and design tool for geosynthetic-
reinforced retaining walls and steep slopes. The program GREWS was derived
from a finite element program DACSAR, an acronym for Deformation Analysis
Considering Stress Anisotropy and Reorientation. The program DACSAR was
developed by Iizuka and Ohta (1987) at Tokyo University, Japan. The program
GREWS has four levels of sophistication (Wu, et al., 1994):
Level-1: Empirical Design
Level-1 is for design only. It can be used for design of geosynthetic-
reinforced retaining walls using limit equilibrium methods, including the
37


U.S. Forest Service ultimate-strength method, AASHTO ultimate-strength
method, and the CTI service-load method.
Level-2: Automated Design or Analysis
Level-2 can be used for analysis and design of geosynthetic-reinforced soil
walls in a variety of different conditions. A set of different automated
finite element meshes has been utilized to accommodate geosynthetic-
reinforced soil walls of different heights, different backfills, different
foundations, and different retained soil conditions.
Level-3: Semi-Automated Design or Analysis
Level-3 allows the user to make modifications to the input of Level-2
design or analysis; moreover, it can be used in situations where the user
wants to specify the material properties.
Level-4: Standard Finite Element Analysis
Level-4 uses standard finite element method for analysis of geosynthetic-
reinforced soil walls. As a result, the user need to input the finite element
mesh, the material properties, the boundary conditions, the loadings, and
construction sequences.
In this study, Level-4 was used for the analysis of the geosynthetic-reinforced tire
shred retaining wall.
38


4.1.1 Element Types of GREWS
GREWS incorporates the following element types (Wu, et al., 1994):
(1) Soil element: Soil elements are four-node quadrilateral elements. Each node has 2 degrees of freedom (horizontal and vertical displacements).
(2) Beam element: Beam elements are two-node straight line elements with axial, shear, and bending stiffness.
(3) Bar element: Bar elements are two-node straight-line elements with axial stiffness only.
(4) Interface element: The interface elements are four-node elements. Each
4.1.2 Soil Models interface element consists of 2 linear elastic perfectly plastic springs (normal and shear springs) which control the displacement between the interface of 2 materials.
GREWS has 3 soil models, a linearly elastic model, a nonlinear elastic
hyperbolic model, and an elasto-viscoplastic model. The elasto-viscoplastic
model incorporated in GREWS is Sekiguchi-Ohta model (Sekiguchi and Ohta,
1977). This model is capable of simulating the time-dependent and time-
39


independent parts of elasto-viscoplastic soils.
For the time independent model, the soil parameters needed are X, p ,
t
oVi ko, kx^/Yw > ky(Z)/yw, ei, and A.k- The following are the meaning of each
parameter.
X : Lames constant
P : Lames constant
t aVi : effective overburden pressure in-situ
ko ^ coefficient of earth pressure at rest
kx(y) / Y w coefficient of permeability in x(y) direction at the reference stress state
ky(z)/Yw coefficient of permeability in y(z) direction at the reference stress state
ei: initial void ratio in-situ
Xk : gradient of e plotted against ln(%)
The time-dependent part of the model was used in this study for simulation
of the tire chips. The parameters needed in this model are D, A, M, o,
t t
kx(y)/Yw5ky(z)/Yw> C7V0 ko, ctv1 ki,a, dv0/dt,X, eo,and The following are
the definition of the parameters.
D : coefficient of dilatancy proposed by Shibata
40


(1963)
A :
M :
u :
kx(y)/yw
ky(z) / y w
Ovo
ko :
aVi
ki :
a :
dvo /dt :
X:
eo
irreversibility ratio expressed as A=l-(kA.)
critical state parameter
effective Poissons ratio
coefficient of permeability in x(r) direction
at the reference stress state
coefficient of permeability in y(z) direction
at the reference stress state
preconsolidation pressure
coefficient of earth pressure at rest
effective overburden pressure in-situ
coefficient of in-situ earth pressure at rest
coefficient of secondary compression
initial volumetric strain rate at reference
state expressed by dvo/dt=a/tc> where tc is
the time at end of primary consolidation
compression index in the e-ln(p'/p0')
relationship
void ratio corresponding with avo' at
41


reference state
Xk
gradient of e plotted against ln(k) plot
4.1.3 Beam and Bar Models
The stress-strain behavior for both beam and bar elements is assumed
linearly elastic in this study. The properties E, A, and I are specified for each
beam element, whereas, the properties E and A are specified for each bar element.
Output includes displacements, moment, trust, and shear for beam elements,
displacements and trust for bar element. The following are the meaning of the
parameters.
E : Youngs modulus of beam or bar
A : cross-sectional area
I: moment of inertia of area
4.1.4 Interface Model
The interface model was similar to the type proposed by Goodman, et al.
(1968), based on the method of stiffness. Two linear spring constants, kn (normal
stiffness) and ks (shear stiffness), are used to simulate the interface behavior in
normal and tangent direction.
The parameters for the interface model are kn, ks, .
42


The following are the meaning of the parameters.
kn: normal stiffness
ks: shear stiffness
ov. : overburden pressure
ki : coefficient of in-situ earth pressure at rest
c: cohesion
tan 4.2 Determination of Material Parameters for Tire Chips
4.2.1 Material Parameters of Tire Chips
Some properties of tire chips were determined from results of one-
dimensional compression tests and direct shear tests, others were by empirical
correlation. The time dependent parameters of Sekiguchi-Ohta model (Sekiguchi
and Ohta, 1977) can be determined as follows:
. , 6xSind)'
M =---------
3-Sine))'
(4.1)
From the direct shear test, therefore,
43


M=1.22
And,
ko= 1 Sin <{>'
= 0.492
For one-dimensional compression tests, the mean stress is:
P =
CTl + 2 X 3
(4.2)
Since
03 kox Ol
0.492 x
Therefore,
p = 0.661x0, (4.3)
The initial void ratio can be computed by the following equation (Sekiguchi and
Ohta, 1977),
Yo =
GsXYw
1 + eo
(4.4)
where yo is the compacted unit weight of tire chips which was 6.3 kN/m3 (40 pcf);
Gs is the specific gravity of tire chips which was 1.24 (Humphrey et ah, 1992);
44


and yw is the unit weight of water which was 9.81 kN/m3 (62.4 pcf). The initial
void ratio of the compacted tire chips was determined to be 0.93.
Choosing a data point (point a) from the stress-strain curve for the tire
chips,
8a = 0.0768
and cra = 12.4 kPa (or 1.8 psi)
therefore, pa = 0.661 x a2 = 8.2 kf a (or 1.2 psi)
The compression box measures, 76.2 cm (30 in.) in width and length, and
48.3 cm (19 in.) in height, thus the surface area was 0.58 m2(900 in.2) and the
volume was 0.28 m3 (17,100 in.3).
From 1-D compression test, AL= 3.71 cm ( or 1.46 in.) (4.5)
thus, AV= AL- Area = 0.022 rn {or 1314 in.3)
Since e = = 0.93 (4.6) Vs
and V = Vv + Vs = 0.28 m3 (or 17100 in.3)
therefore, e. = V'-AV=0.78 Vs
Choosing another test data point (point b) from the stress-strain curve for
the tire chips,
eb = 0.1589
45


ab = 35.9 kPa (or 5.2 psi)
Using the above procedure,
pb = 23.7 kPa (or 3.4 psi)
eb = 0.62
Since
X =
ea -eb
P,
thus,
Assuming
thus,
Knowing that,
thus,
A. = 0.17
k = 0.5-A
k = 0.085
A = 1 and D =-----------
/L M-(l + eo)
A = 0.5
D = 0.036
The coefficient of secondary compression is expressed as a = 5v/8(lnt),
where v is volumetric strain. It is noted that in one-dimensional compression test,
the volumetric strain (v) is equal to vertical strain (V) and can be obtained for the
vertical displacement. Casagrandes logarithm of time fitting method was used to
46


determine the value a. However, instead of plotting displacement versus
logarithm of time, the vertical strain versus logarithm of time was plotted in
Figure 4.1. The coefficient of secondary compression, a, is the slope of the
secondary compression curve which is equal to 0.00058.
The initial volumetric strain rate can be calculated by dv0/dt= a/ tc, where
tc=t9o- The Taylors square root of time fitting method was applied to obtain t90,
which was equal to 31,500 min (see Figure 4.2 for vertical strain versus square
root of time plot). Therefore, dvo/dt = 1.8xl O8 min'1.
The kX(r) ky the coefficients of permeability were assumed to be the
average value obtained by the permeability test conducted by Humphrey et al.
(1992). Both kX(r) and ky(Z) were assumed to be equal to 11.15 cm/s (4.4 in./s).
The unit weight of tire chips in the one-dimensional compression test is 6.3 kN/m3
(40 pcf), and the height of the sample was 48.3 cm (19 in); therefore, the average
t
effective overburden pressure ( ctv. ) was 1.5 kPa (0.22 psi). Table 4.1
summarizes the Sekiguchi-Ohta material parameters of the tire chips.
4.2.2 Material Parameters of Foundation Soil
According to the foundation report for uphill retaining walls at Shoshone
Dam in Glenwood Canyon published by the Colorado Department of Highways, a
47


depth from 0 to 6.1 meter (20 ft) consists of colluvial nature and primarily of talus
in a matrix of sandy gravel with scattered cobbles and boulders (Bell, et al., 1983).
Some soil properties were selected based on the soil type. The unit weight,
Youngs modulus (E), friction angle (<{>), Poissons ratio (v ), coefficient of
permeability (k), and initial void ratio (eo) of the soil are shown in Table 4.2.
Using the equations,
~ v-E ~ E
A =--------------- and u. = --------
(l + v)(l-2v) 2(1 + v)
therefore, A = 80.64 kg/ cm2 (or 1147 psi)
jl = 25.5 kg/ cm2 (or 362 psi)
The unit weight of soil was 15.7 kN/m3 (100 pcf), and the height of a tier
f
was 3.05 m (10 ft); therefore, the average effective overburden pressure (cjVi ) was
23.9 kPa (500 psf). The linear elastic soil parameters of the foundation soil are
shown in Table 4.3.
48


Table 4.1 Material Parameters for Sekiguchi-Ohta Model
D 0.036 f GVi 0.015 kg/cm2 (1.5 kPa)
A 0.5 ki 0.49
M 1.22 a 0.00058
V 0.1 dvo /dt 1.8xi O'8 min1
kx(Tr)/yw 11.15 cm/s-yw X 0.17
ky(z)! Yw 11.15 cm/s-yw e0 0.93
t CTvo 0.015 kg/cm2 (1.5 kPa) Ak 0.17
ko 0.492
Table 4.2 Properties of Foundation Soil
y 0.0016 kg/cm3 (100 pcf) D 0.38
E 70.31 kg/cm2 (1000 psi) K 0.01 cm/s
* 40 eo 1.0
Table 4.3 Material Parameters for Foundation Soil
X 80.64 kg/cm2 kx(r)/yw 0.01 cm/s-yw
P 25.5 kg/cm2 ky(z)^ Yw 0.01 cm/s-yw
f (TVj 0.24 kg/cm2 & 1.0
ko 0.357 A,k 0
49


4.2.3 Material Parameters of Facing and Geogrid Reinforcement
In the finite element analysis, the wall face was simulated by a series of
beam elements and reinforcement by a series of bar elements. The wall face was
comprised of tire blocks, which were made of melted compressed tires. Each tire
block measures approximately 122 cm (4 ft) long, 61 cm (2 ft) high, and 45.7 cm
(1.5 ft) wide (see Figure 4.3). Tensar UX-1400 geogrid was installed at 61 cm (2
ft) vertical spacing. The material parameters of the beam and bar elements are
shown in Table 4.4 and Table 4.5.
Table 4.4 Material Parameters for Beam Elements.
E 281 kg/cm2 (4000 psi)
A 116.1 cm2 (18 in2)
I 20200 cm4 (486 in4)
Table 4.5 The Input Geogrid Parameters for Bar Elements.
E 1.4 kg/cm2 (20 psi)
A 1.61 cm2 (0.25 in2)
50


Strain (%)
log (time) (min)
Figure 4.1 Vertical Strain vs. Logarithm of Time in One-dimensional
Compression Test
51


Strain (%)
(min'71)
Figure 4.2 Vertical Strain vs. Square Root of Time in One-dimensional
Compression Test
52


53


4.2.4 Material Parameters of Soil-Tire Chips Interface
Two linear spring constants, ks (shear stiffness) and kn (normal stiffness),
were used to simulate the interface behavior on tangent and normal directions at
the soil-tire chip interface. The ks was the slope of the shear stress versus relative
displacement curve and was assumed to be 1/2 of the initial ks value of the tire
chips alone. The kn was assumed to be a large value in order to prevent
penetration of the contacting nodes.
The friction angle was assumed to be 2/3 of the internal friction angle of
the tire chips, and the cohesion of the interface was assumed to be 1/2 of the
cohesion of tire chips. The coefficient of in-situ early pressure at-rest, kj was
calculated as ki = 1 sin<|>.
The unit weight of tire chips was 6.3 kN/m (40 pcf) and the average
height of backfill was 4.7 m (15.5 ft), hence the overburden pressure kPa (620 psf). The material parameters of interface model are shown in Table 4.6.
Table 4.6 The Input of the Interface Parameters.
ks 0.0038 kg/cm3 ki 0.653
kn 1,000,000 kg/cm3 C 0
54


4.3 Finite Element Analysis of the One-Dimensional Compression Test
The purpose of this study was to determine engineering properties of the
tire chips and to predict the long-term performance of the Glenwood Canyon tire
chip test wall. It was assumed that the material characteristics of the using the soil
tire chips are similar to those of soils; as a result, some property tests were
conducted testing methods. The data resources for tire chips are very limited,
hence it was necessary to perform some property tests for the tire chips. However,
the test results might vary under different test conditions. For example, different
apparatus, size of tire chips, and temperature may significantly change the
properties of the tire chips. Therefore, back analysis was needed to determine
properties of the tire chip in finite element analyses.
GREWS was first used to simulate the one- dimensional compression test.
The main purpose of the analysis was to make adjustments of the input parameters
for tire chip properties. The strain versus time curve as shown in Figure 3.6, for
the tire chips was used for the back-analysis.
The simulation of one-dimensional compression test assumed the test box
was in an axi-symmetric condition. The radius of the equivalent cylindrical box
was computed by % x r2 = A, where r is the equivalent radius, and A is the total
area of the test box which is equal to 0.58 m (900 in. ); therefore, r is equal to 43
55


cm (16.9 in.). A finite element mesh was established as shown in Figure 4.4. The
mesh includes 5 quadrilateral elements and 12 nodes.
Material parameters listed in Table 4.1 were first used in the analysis of
the one-dimensional compression test. The results were compared with Figure
3.6. The input data for this analysis are shown in Appendix C.
Figure 4.5 shows a comparison of the creep curves obtained from GREWS
analysis and the actual test. It is noted that the analysis shows a slightly smaller
instantaneous strain (about 0.2 % lower) than the measured value. However, the
creep behavior is almost identical. The adjusted material parameters of the tire
chips are shown in Table 4.7. These adjusted parameters of the tire chips were
used in the finite element analysis for the Glenwood Canyon tire chip test wall.
Table 4.7 The Adjusted Input Parameters for Tire Chips
D 0.036 r aVi 0.015 kg/cm2 1.5 kPa)
0.5 ki 0.49
M 1.22 a 0.055
V 0.1 dvo/dt 1.2xi o'4 min'1
kx(y)/ Yw 11.15 cm/s-yw X 0.17
ky(z)/ Y w 11.15 cm/s-yw eo 0.93
t Ovo 0.015 kg/cm2 1.5 kPa) 0.17
ko 0.492
56


Surcharge
Figure 4.4 The Finite Element Mesh for One-dimensional Compression Test
57


9 r
18 1
.s' 17 4* 1

20,000 40,000 60,000
Time (min)
Test -GREWS
Figure 4.5 The Comparison of the Creep Behavior of Tire Chips from GREWS
Analysis and One-dimensional Compression Test
15 L
0
58


4.4 Finite Element Analysis of the Glenwood Canyon Test Wall
A finite element mesh was established for the Glenwood Canyon test wall
as shown in Figure 4.6. The mesh includes 327 quadrilateral/triangular elements
for simulation of the fill, 31 beam elements for simulation of the compressed tire
block face, 231 bar elements for simulation of the geogrid reinforcement, and 42
interface elements for simulation of the contact surface between tire chips fill and
the in-situ foundation soil. The analysis simulated the field construction
sequences and time table. In this analysis, the test wall was constructed in 44
increments and it took four months to complete the construction in the field.
Material parameters listed in Tables 4.3 to Table 4.7 were used as input
parameters, and all the input data are shown in Appendix D.
59


Figure 4.6 Finite Element Mesh for Glenwood Canyon Test Wall


4.4.1 Comparison of Measured Results and Finite Element Analysis Results
This finite element analysis was performed based on the time dependent
model and time zero means the first day of construction. Construction of the test
wall was completed in about 4 months. The elapsed time for the analysis was 7
months, i.e., 3 months beyond the end of construction. A comparison of the wall
face deformation of the analysis with the measured wall face deformation 7
months after the construction started is shown in Figure 4.7. It is seen the analysis
shows slightly larger deformation than the measured value. This is considered
acceptable, as the predicted deformation beyond the measurement period is likely
to be on the conservative side.
4.4.2 Predicted Wall Movement of Glenwood Canyon Test Wall
Predicted wall movement at 75 years after construction is depicted in
Figure 4.8. The maximum movement at 75 years after construction is predicted to
be 2.8 m (9.1 ft), which occurs near the 7th tier. The wall movement at 7 months
is also presented for comparison. It is seen that, since the deformation rate was
decreasing with time, the movement from 7 months to 75 years is smaller than the
movement in the first 7 months. It should be noted that movement is still
occurring, although at a very slow rate, at 75 years after construction.
61


Figure 4.7 Comparison of Measured and Finite Element Analysis Result


Figure 4.8 Predicted Wall Movement after 75 Years of Glenwood Canyon Test Wall


5. Summary and Conclusions
5.1 Summary
In October 1994, the Colorado Department of Transportation constructed a
geosynthetic-reinforced retaining wall using shredded tires as backfill. The retaining
wall was constructed over a landslide area along Interstate Highway-70 near
Glenwood Canyon, Colorado. The retaining wall was constructed in 7 tiers with a
total height of 21 m (70 ft). To the authors knowledge, this was (and still is) the
highest tire-shred retaining wall in the world. The wall was instrumented with survey
targets and horizontal inclinometers at strategic locations to monitor its performance
during and after construction.
This study was undertaken to determine the engineering properties of the
shredded tires (a nominal size of 5 cm (2 in.) and to investigate the long-term
performance the geosynthetic-reinforced retaining wall. Long-term one-dimensional
compression tests and direct shear tests were performed using a specially designed
apparatus that can accommodate a specimen size of 76 cm by 76 cm by 61 cm (30 in.
by 30 in. by 24 in.). The one-dimensional compression tests were performed by
applying incremental loads to the top surface of the test specimen. After a maximum
pressure of 51.7 kN/m2 (7.5 psi) was reached, the load was maintained for 42 days.
64


y
The direct shear tests were performed under 3 overburden pressures: 34.5 kN/m 51.7
2 2
kN/m and 69.0 kN/m (5 psi, 7.5 psi, and 10 psi). All tests were performed at an
initial unit weight of 6.3 kN/m (40 lb/ft). The measured properties were then used
to conduct finite element analysis using a computer model, GREW. The finite
element model is capable of analyzing the time-dependent performance of the
retaining wall due to its self-weight and externally applied loads.
To validate the finite element model, the deformed configuration of the
retaining wall as computed by the finite element model was compared with the
measured deformation. After the model was properly validated, the analytical model
was employed to predict the long-term performance of the retaining wall over its
design life.
5.2 Findings and Conclusions
The findings and conclusions of this study can be grouped into 3 areas: (A)
laboratory tests, (B) measured performance versus finite element analysis, and (C)
long-term performance of the Glenwood Canyon retaining wall.
(A) Laboratory Tests
The long-term one-dimensional compression tests indicated that the
shredded tires experienced large time-dependent deformation. The
deformation decreased with time at a decreasing rate. At the end of
65


the test (42 days under 51.7 kN/m (7.5 psi) surcharge pressure), the
total deformation was approximately 17.5%, and the strain rate was
0.43% per day, approximately 1/40 of the strain rate in the first day of
the 51.7 kN/m (7.5 psi) surcharge pressure.
The direct shear test results indicated that the Mohr failure envelope
was fairly close to being a straight line. The angle of internal friction
of the tire chips was 30.5 degrees, and the cohesion was very small
0.2 kN/m2 (4.4 lb/ft2).
(B) Measured Performance vs. Finite Element Analysis
The retaining wall experienced large deformation. Three months
after construction, the maximum downward movement was 109 cm
(3.6 ft) and the maximum outward movement was 138 cm (4.5 ft),
measured in the 6th tier (second tier from the top) of the wall.
Upon calibrations with the measured results, very good general
agreement was observed between the calculated deformed
configuration of the wall 3 months after construction and the
measured deformation. This indicates that the finite element model is
capable of analyzing time-dependent performance of the retaining
wall.
66


(C) Long-Term Performance
Using the analytical model, the maximum movement of the wall will
be approximately 9.1 ft (2.8 m), 75 years after construction. This
would be excessive by any measures.
The Colorado Department of Transportation attempted several
remedial measures to arrest the wall movement, but without any
success. The wall was subsequently demolished following a fire due
to self-combustion.
Future usage of shredded tires as backfill of retaining walls will
require further study to find solutions to the following questions: (a)
what are the optimum size of shredded tires for construction of
retaining walls, (b) how to reduce deformation of shredded tires, (c)
how to effectively compact shredded tires in the field, and (d) how to
avoid self-combustion of shredded tires.
67


Appendix A
Survey Data:
Date: 5/25/1995
Tier No. Survey Point Location Displacement (ft)
1 Bottom 0.162 Y
0.210 X
1 Top 0.143 Y
0.200 X
2 Bottom 0.191 Y
0.320 X
2 Top 0.221 Y
0.435 X
3 Bottom 0.588 Y
1.375 X
3 Top 0.543 Y
2.000 X
4 Bottom 1.375 Y
2.655 X
4 Top 1.365 Y
3.260 X
5 Bottom 3.284 Y
4.150 X
5 Top 2.860 Y
4.270 X
6 Bottom 3.576 Y
4.440 X
6 Top 3.569 Y
4.525 X
7 Bottom 3.368 Y
3.980 X
7 Top 3.328 Y
3.955 X
68


Initial data for Glenwood Canyon test wall
TUBE A
depth A+ A- INI. DIFF
2 -279 235 -514
3 -312 270 -582
4 -331 289 -620
5 -372 332 -704
6 -409 368 -777
7 -423 383 -806
8 -460 417 -877
9 -532 491 -1023
10 -581 540 -1121
11 -601 560 -1161
12 -625 584 -1209
13 -606 563 -1169
14 -570 528 -1098
15 -563 521 -1084
69


Data for Glenwood Canyon test wall
TUBE A
INI. DIFF. depth A+ A-
-514 2 -417 367
-582 3 -459 409
-620 4 -437 386
-704 5 -356 304
-777 6 -302 251
-806 7 -338 287
-877 8 -418 365
-1023 9 -512 457
-1121 10 -537 '488
-1161 11 -519 466
-1209 12 -509 457
-1169 13 -479 427
-1098 14 -474 422
-1084 15 -505 454
11/27/94
DIFF. CHANGE
-784 270
-868 286
-823 203
-660 44
-553 224
-625 181
-783 94
-969 54
-1025 96
-985 176
-966 243
-906 263
-896 202
-959 125
DEFF.in. step2(d)
5.3256 -5.3256
4.5873 -4.5873
3.93 -3.93
3.3585 -3.3585
2.8479 -2.8479
2.3505 -2.3505
1.9203 -1.9203
1.5444 -1.5444
1.1967 -1.1967
0.8652 -0.8652
0.5625 -0.5625
0.3126 -0.3126
0.1356 -0.1356
0.0375 -0.0375
SUM(C.
2461
2191
1905
1702
1658
1434
1253
1159
1105
1009
833
590
327
125


Data for Glenwood Canyon test wall 12/18/94
TUBE A
INI. DIFF. depth A+ A- DIFF.
-784 2 -362 301 -663
-868 3 -432 371 -803
-823 4 -438 382 -820
-660 5 -375 316 -691
-553 6 -317 259 -576
-625 7 -339 282 -621
-783 8 -406 347 -753
-969 9 -491 436 -927
-1025 10 -529 471 -1000
-985 11 -507 448 -955
-966 12 -500 442 -942
-906 13 -471 411 -882
-896 14 -471 412 -883
-959 15 -504 444 -948
CHANGE SUM(C.) DEFF.in
121 446 0.7407
65 325 0.6069
3 260 0.5094
31 257 0.4314
23 226 0.3543
4 203 0.2865
30 199 0.2256
42 169 0.1659
25 127 0.1152
30 102 0.0771
24 72 0.0465
24 48 0.0249
13 24 0.0105
11 11 0.0033
-0.7407 -5.3256 step3(d) -6.0663
-0.6069 -4.5873 -5.1942
-0.5094 -3.93 -4.4394
-0.4314 -3.3585 -3.7899
-0.3543 -2.8479 -3.2022
-0.2865 -2.3505 -2.637
-0.2256 -1.9203 -2.1459
-0.1659 -1.5444 -1.7103
-0.1152 -1.1967 -1.3119
-0.0771 -0.8652 -0.9423
-0.0465 -0.5625 -0.609
-0.0249 -0.3126 -0.3375
-0.0105 -0.1356 -0.1461
-0.0033 -0.0375 -0.0408


Data for Glenwood Canyon test wall
TUBE A
-j
to
A+ A- DIFF.
-321 272 -593
-408 358 -766
-440 392 -832
-388 337 -725
-320 272 -592
-355 288 -643
-391 341 -732
-479 427 -906
-518 470 -988
-494 445 -939
-488 438 -926
-469 410 -879
-468 416 -884
-499 447 -946
depth
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1/14/95
INI. DIFF. CHANGE
-663 70
-803 37
-820 12
-691 34
-576 16
-621 22
-753 21
-927 21
-1000 12
-955 16
-942 16
-882 3
-883 1
-948 2
SUM(C) DEF. in
283 0.4092
213 0.3243
176 0.2604
164 0.2076
130 0.1584
114 0.1194
92 0.0852
71 0.0576
50 0.0363
38 0.0213
22 0.0099
6 0.0033
3 0.0015
2 0.0006
-6.0663 step4(d) -6.4755
-5.1942 -5.5185
-4.4394 -4.6998
-3.7899 -3.9975
-3.2022 -3.3606
-2.637 -2.7564
-2.1459 -2.2311
-1.7103 -1.7679
-1.3119 -1.3482
-0.9423 -0.9636
-0.609 -0.6189
-0.3375 -0.3408
-0.1461 -0.1476
-0.0408 -0.0414


Data for Glenwood Canyon test wall
TUBE A
-j
A+ A- DIFF
-279 224 -503
-380 324 -704
-444 387 -831
-404 349 -753
-323 269 -592
-334 279 -613
-386 327 -713
-468 413 -881
-513 457 -970
-484 428 -912
-481 422 -903
-471 394 -865
-473 410 -883
-495 438 -933
depth
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1/25/95
INI. DIFF. CHANGE
-593 90
-766 62
-832 1
-725 28
-592 0
-643 30
-732 19
-906 25
-988 18
-939 27
-926 23
-879 14
-884 1
-946 13
SUM(C) DEF. in
351 0.567
261 0.4617
199 0.3834
198 0.3237
170 0.2643
170 0.2133
140 0.1623
121 0.1203
96 0.084
78 0.0552
51 0.0318
28 0.0165
14 0.0081
13 0.0039
-6.4755 step5(d) -7.0425
-5.5185 -5.9802
-4.6998 -5.0832
-3.9975 -4.3212
-3.3606 -3.6249
-2.7564 -2.9697
-2.2311 -2.3934
-1.7679 -1.8882
-1.3482 -1.4322
-0.9636 -1.0188
-0.6189 -0.6507
-0.3408 -0.3573
-0.1476 -0.1557
-0.0414 -0.0453


Data for Glenwood Canyon test wall
Tube A
depth A+ A- DIFF.
2 -276 271 -547
3 -239 184 -423
4 -603 569 -1172
5 -759 713 -1472
6 -527 478 -1005
7 -350 308 -658
8 -392 340 -732
9 -380 354 -734
10 -215 -111 -104
11 -1 -377 376
12 -64 -140 76
13 22 -317 339
14 -12 -250 238
15 -403 257 -660
5/25/95
INI. DIFF. CHANGE SUM(C)
-503 44 7740
-704 281 7696
-831 341 7415
-753 719 7074
-592 413 6355
-613 45 5942
-713 19 5897
-881 147 5878
-970 866 5731
-912 1288 4865
-903 979 3577
-865 1204 2598
-883 1121 1394
-933 273 273
DEF. in. 21.7305 -7.0425 Step6 (d) -28.773
19.4085 -5.9802 -25.3887
17.0997 -5.0832 -22.1829
14.8752 -4.3212 -19.1964
12.753 -3.6249 -16.3779
10.8465 -2.9697 -13.8162
9.0639 -2.3934 -11.4573
7.2948 -1.8882 -9.183
5.5314 -1.4322 -6.9636
3.8121 -1.0188 -4.8309
2.3526 -0.6507 -3.0033
1.2795 -0.3573 -1.6368
0.5001 -0.1557 -0.6558
0.0819 -0.0453 -0.1272


Initial data for Glenwood Canyon test wall
TUBE B
depth, ft A+ A- INI.DIFF
2 -732 687 -1419
3 -704 662 -1366
4 -662 622 -1284
5 -615 574 -1189
6 -568 525 -1093
7 -518 478 -996
8 -470 426 -896
9 -427 385 -812
10 -373 329 -702
11 -302 259 -561
12 -257 212 -469
13 -218 176 -394
14 -168 126 -294
75


Data for Glenwood Canyon test wall 11/27/94
TUBE B
INI.DIFF. depth, ft A+ A- DIFF. CHANGE SUM(C.) DEFF.in. step 2(d.
-1419 2 -718 668 -1386 33 1600 4.1751 -4.1751
-1366 3 -688 643 -1331 35 1567 3.6951 -3.6951
-1284 4 -658 615 -1273 11 1532 3.225 -3.225
-1189 5 -555 503 -1058 131 1521 2.7654 -2.7654
-1093 6 -480 434 -914 179 1390 2.3091 -2.3091
-996 7 -490 442 -932 64 1211 1.8921 -1.8921
-896 8 -517 463 -980 84 1147 1.5288 -1.5288
-812 9 -475 429 -904 92 1063 1.1847 -1.1847
-702 10 -303 255 -558 144 971 0.8658 -0.8658
-561 11 -171 117 -288 273 827 0.5745 -0.5745
-469 12 -156 103 -259 210 554 0.3264 -0.3264
-394 13 -146 94 -240 154 344 0.1602 -0.1602
-294 14 -79 25 -104 190 190 0.057 -0.057


Data for Glenwood Canyon test wall 12/18/94
TUBE B
INI.DIFF. depth, ft A+ A- DIFF.
-1386 2 -697 634 -1331
-1331 3 -653 597 -1250
-1273 4 -683 616 -1299
-1058 5 -575 518 -1093
-914 6 -481 423 -904
-932 7 -479 422 -901
-980 8 -516 457 -973
-904 9 -477 425 -902
-558 10 -315 267 -582
-288 11 -176 121 -297
-259 12 -161 104 -265
-240 13 -137 78 -215
-104 14 -55 -80 25
CHANGE SUM(C.)
55 440
81 385
26 304
35 278
10 243
31 233
7 202
2 195
24 193
9 169
6 160
25 154
129 129
DEFF.in.
0.9255 -0.9255
0.7935 -0.7935
0.678 -0.678
0.5868 -0.5868
0.5034 -0.5034
0.4305 -0.4305
0.3606 -0.3606
0.3 -0.3
0.2415 -0.2415
0.1836 -0.1836
0.1329 -0.1329
0.0849 -0.0849
0.0387 -0.0387
-4.1751 step 3(d.) -5.1006
-3.6951 -4.4886
-3.225 -3.903
-2.7654 -3.3522
-2.3091 -2.8125
-1.8921 -2.3226
-1.5288 -1.8894
-1.1847 -1.4847
-0.8658 -1.1073
-0.5745 -0.7581
-0.3264 -0.4593
-0.1602 -0.2451
-0.057 -0.0957


Data for Glenwood Canyon test wall
TUBE B
depth A+ A- DIFF.
2 -654 609 -1263
3 -618 567 -1185
4 -667 617 -1284
5 -575 530 -1105
6 -469 418 -887
7 -469 421 -890
8 -511 457 -968
9 -473 423 -896
10 -307 255 -562
11 -168 119 -287
12 -158 92 -250
13 -123 58 -181
14 -75 -14 -61
1/14/95
INI. DIFF. CHANGE SUM DEF. in. step4(d)
-1331 68 364 0.7488 -5.1006 -5.8494
-1250 65 296 0.6396 -4.4886 -5.1282
-1299 15 231 0.5508 -3.903 -4.4538
-1093 12 216 0.4815 -3.3522 -3.8337
-904 17 204 0.4167 -2.8125 -3.2292
-901 11 187 0.3555 -2.3226 -2.6781
-973 5 176 0.2994 -1.8894 -2.1888
-902 6 171 0.2466 -1.4847 -1.7313
-582 20 165 0.1953 -1.1073 -1.3026
-297 10 145 0.1458 -0.7581 -0.9039
-265 15 135 0.1023 -0.4593 -0.5616
-215 34 120 0.0618 -0.2451 -0.3069
25 86 86 0.0258 -0.0957 -0.1215


Data for Glenwood Canyon test wall
TUBE B
depth A+ A- DIFF.
2 -616 560 -1176
3 -590 536 -1126
4 -675 618 -1293
5 -597 537 -1134
6 -470 414 -884
7 -463 410 -873
8 -503 452 -955
9 -483 425 -908
10 -309 259 -568
11 -167 116 -283
12 -145 85 -230
13 -105 51 -156
14 -39 -18 -21
1/25/95
II. DIFF. CHANGE SUM
-1263 87 324
-1185 59 237
-1284 9 178
-1105 29 169
-887 3 140
-890 17 137
-968 13 120
-896 12 107
-562 6 95
-287 4 89
-250 20 85
-181 25 65
-61 40 40
DEF. in. 0.5358 -5.8494 step5(d) -6.3852
0.4386 -5.1282 -5.5668
0.3675 -4.4538 -4.8213
0.3141 -3.8337 -4.1478
0.2634 -3.2292 -3.4926
0.2214 -2.6781 -2.8995
0.1803 -2.1888 -2.3691
0.1443 -1.7313 -1.8756
0.1122 -1.3026 -1.4148
0.0837 -0.9039 -0.9876
0.057 -0.5616 -0.6186
0.0315 -0.3069 -0.3384
0.012 -0.1215 -0.1335


Data for Glenwood Canyon test wall
Tube B
depth A+ A- DIFF.
2 -616 527 -1143
3 -202 154 -356
4 -910 855 -1765
5 -922 868 -1790
6 -410 360 -770
7 -205 153 -358
8 -503 446 -949
9 -366 289 -655
10 339 -420 759
11 601 -668 1269
12 298 -422 720
13 102 -150 252
14 49 -99 148
5/25/95
II. DIFF. CHANGE SUM
-1176 33 7225
-1126 770 7192
-1293 472 6422
-1134 656 5950
-884 114 5294
-873 515 5180
-955 6 4665
-908 253 4659
-568 1327 4406
-283 1552 3079
-230 950 1527
-156 408 577
-21 169 169
DEF. in. 16.9035 -6.3852 step6(d) -23.2887
14.736 -5.5668 -20.3028
12.5784 -4.8213 -17.3997
10.6518 -4.1478 -14.7996
8.8668 -3.4926 -12.3594
7.2786 -2.8995 -10.1781
5.7246 -2.3691 -8.0937
4.3251 -1.8756 -6.2007
2.9274 -1.4148 -4.3422
1.6056 -0.9876 -2.5932
0.6819 -0.6186 -1.3005
0.2238 -0.3384 -0.5622
0.0507 -0.1335 -0.1842


Appendix B
One-dimensional Compression Test
Date Stress Stress Stress Time Elap. T DISP. DISP. Strain Strain/T Disp/T DISP/T
/1995 Airbag Calc'd Pa min min in cm /min in/min cm/min
2/16 0 0.063 434.4 0 0 0 0 0 0
2/17 2.00 1.772 12217.9 1440 1.4592 3.7064 0.0768 10.1333 25.7387
2/18 4.00 3.481 24001.5 2880 2.3636 6.0035 0.1244 8.2069 20.8456
2/19 6.00 5.189 35778.2 4320 3.0191 7.6685 0.1589 6.9887 17.7512
2/20 6.70 5.787 39902.5 4500 3.1160 7.9146 0.1640 6.9244 17.5881
2/20 7.10 6.129 42258.6 4680 3.1863 8.0932 0.1677 6.8083 17.2932
2/20 7.30 6.300 43436.7 4860 3.2148 8.1656 0.1692 6.6148 16.8016
2/20 7.40 6.385 44025.7 5040 3.2319 8.2090 0.1701 6.4125 16.2878
2/20 7.43 6.411 44202.4 5220 3.2395 8.2283 0.1705 6.2059 15.7631
2/20 7.47 6.445 44438.0 5400 3.2471 8.2476 0.1709 6.0131 15.2734
2/20 7.49 6.462 44555.8 5580 3.2547 8.2669 0.1713 5.8328 14.8153
2/20 7.50 6.471 44617.5 5760 0 3.2604 8.2814 0.1716 0 5.6604 14.3775
2/21 7.50 6.471 44617.5 7200 1440 3.2655 8.2944 0.1719 11.9353 4.5354 11.5200
2/22 7.50 6.471 44617.5 8640 2880 3.2706 8.3073 0.1721 5.9770 3.7854 9.6150
2/23 7.50 6.471 44617.5 10080 4320 3.2750 8.3185 0.1724 3.9900 3.2490 8.2525
2/24 7.50 6.471 44617.5 11520 5760 3.2804 8.3322 0.1727 2.9974 2.8476 7.2328
2/25 7.50 6.471 44617.5 12960 7200 3.2849 8.3436 0.1729 2.4012 2.5346 6.4380
2/26 7.50 6.471 44617.5 14400 8640 3.2891 8.3543 0.1731 2.0036 2.2841 5.8016


Date Stress Stress Stress Time Elap. T
/1995 Airbag Calc'd Pa min min
2/27 7.50 6.471 44617.5 15840 10080
2/28 7.50 6.471 44617.5 17280 11520
3/1 7.50 6.471 44617.5 18720 12960
3/2 7.50 6.471 44617.5 20160 14400
3/3 7.50 6.471 44617.5 21600 15840
3/4 7.50 6.471 44617.5 23040 17280
3/5 7.50 6.471 44617.5 24480 18720
3/6 7.50 6.471 44617.5 25920 20160
3/7 7.50 6.471 44617.5 27360 21600
3/8 7.50 6.471 44617.5 28800 23040
3/9 7.50 6.471 44617.5 30240 24480
3/10 7.50 6.471 44617.5 31680 25920
3/11 7.50 6.471 44617.5 33120 27360
3/12 7.50 6.471 44617.5 34560 28800
3/13 7.50 6.471 44617.5 36000 30240
3/14 7.50 6.471 44617.5 37440 31680
3/15 7.50 6.471 44617.5 38880 33120
3/16 7.50 6.471 44617.5 40320 34560
3/17 7.50 6.471 44617.5 41760 36000
3/18 7.50 6.471 44617.5 43200 37440
3/19 7.50 6.471 44617.5 44640 38880
DISP. DISP. Strain
in cm
3.2923 8.3624 0.1733
3.2954 8.3703 0.1734
3.2983 8.3777 0.1736
3.3002 8.3825 0.1737
3.3024 8.3881 0.1738
3.3049 8.3944 0.1739
3.3065 8.3985 0.1740
3.3078 8.4018 0.1741
3.3090 8.4049 0.1742
3.3104 8.4084 0.1742
3.3116 8.4115 0.1743
3.3127 8.4143 0.1744
3.3137 8.4168 0.1744
3.3146 8.4191 0.1745
3.3155 8.4214 0.1745
3.3163 8.4234 0.1745
3.3170 8.4252 0.1746
3.3177 8.4270 0.1746
3.3184 8.4287 0.1747
3.3189 8.4300 0.1747
3.3194 8.4313 0.1747
Strain/T Disp/T DISP/T
/min in/min cm/min
1.7190 2.0785 5.2793
1.5056 1.9071 4.8439
1.3395 1.7619 4.4753
1.2062 1.6370 4.1580
1.0973 1.5289 3.8834
1.0066 1.4344 3.6434
0.9296 1.3507 3.4308
0.8636 1.2762 3.2414
0.8063 1.2094 3.0720
0.7562 1.1494 2.9196
0.7120 1.0951 2.7816
0.6727 1.0457 2.6560
0.6374 1.0005 2.5413
0.6057 0.9591 2.4361
0.5771 0.9210 2.3393
0.5510 0.8858 2.2498
0.5271 0.8531 2.1670
0.5053 0.8228 2.0900
0.4851 0.7946 2.0184
0.4666 0.7683 1.9514
0.4493 0.7436 1.8887


Date Stress Stress Stress Time Elap. T
/1995 Airbag Calc'd Pa min min
3/19 7.50 6.471 44617.5 44640 38880
3/20 7.50 6.471 44617.5 46080 40320
3/21 7.50 6.471 44617.5 47520 41760
3/22 7.50 6.471 44617.5 48960 43200
3/23 7.50 6.471 44617.5 50400 44640
3/24 7.50 6.471 44617.5 51840 46080
3/25 7.50 6.471 44617.5 53280 47520
3/26 7.50 6.471 44617.5 54720 48960
3/27 7.50 6.471 44617.5 56160 50400
3/28 7.50 6.471 44617.5 57600 51840
3/29 7.50 6.471 44617.5 59040 53280
3/30 7.50 6.471 44617.5 60480 54720
3/31 7.50 6.471 44617.5 61920 56160
4/1 7.50 6.471 44617.5 63360 57600
4/2 7.50 6.471 44617.5 64800 59040
DISP. DISP. Strain
in cm
3.3194 8.4313 0.1747
3.3199 8.4325 0.1747
3.3206 8.4343 0.1748
3.3210 8.4353 0.1748
3.3213 8.4361 0.1748
3.3216 8.4369 0.1748
3.3219 8.4376 0.1748
3.3222 8.4384 0.1749
3.3227 8.4397 0.1749
3.3233 8.4412 0.1749
3.3235 8.4418 0.1749
3.3238 8.4424 0.1749
3.3240 8.4430 0.1749
3.3243 8.4436 0.1750
3.3245 8.4442 0.1750
Strain/T Disp/T DISP/T
/min in/min cm/min
0.4493 0.7436 1.8887
0.4334 0.7205 1.8300
0.4185 0.6988 1.7749
0.4046 0.6783 1.7229
0.3916 0.6590 1.6738
0.3794 0.6407 1.6275
0.3679 0.6235 1.5836
0.3571 0.6071 1.5421
0.3470 0.5916 1.5028
0.3374 0.5770 1.4655
0.3283 0.5629 1.4298
0.3197 0.5496 1.3959
0.3115 0.5368 1.3635
0.3038 0.5247 1.3326
0.2964 0.5130 1.3031


Date GREWS
/1995 in
2/16 0
2/17 3.8483
2/18 3.7838
2/19 3.7621
2/20 3.7607
2/20 3.7591
2/20 3.7575
2/20 3.7560
2/20 3.7544
2/20 3.7529
2/20 3.7515
2/20 3.7501
2/21 3.7401
2/22 3.7331
2/23 3.7279
2/24 3.7241
2/25 3.7212
2/26 3.7190
2/27 3.7173
2/28 3.7161
3/1 3.7151
3/2 3.7144
3/3 3.7139
3/4 3.7136
3/5 3.7134
3/6 3.7134
3/7 3.7134
3/8 3.7136
3/9 3.7139
3/10 3.7142
GREWS GREWS
cm Reading
0 48.2600
9.7747 38.48535
9.6110 38.64905
9.5558 38.7042
9.5522 38.70785
9.5482 38.7118
9.5441 38.71585
9.5402 38.71985
9.5362 38.72385
9.5324 38.7276
9.5288 38.73125
9.5253 38.7347
9.4999 38.7601
9.4820 38.778
9.4689 38.7911
9.4592 38.8008
9.4518 38.8082
9.4463 38.81375
9.4420 38.81805
9.4388 38.8212
9.4364 38.82365
9.4346 38.8254
9.4334 38.82665
9.4326 38.82745
9.4322 38.82785
9.4321 38.82795
9.4322 38.82785
9.4326 38.8274
9.4332 38.8268
9.4341 38.8259
84


Date GREWS
/1995 in
3/11 3.7147
3/12 3.7153
3/13 3.7162
3/14 3.7176
3/15 3.7208
3/16 3.7255
3/17 3.7271
3/18 3.7325
3/19 3.7383
3/20 3.7499
3/21 3.7528
3/22 3.7602
3/23 3.7709
3/24 3.7722
3/25 3.7831
3/26 3.7908
3/27 3.7918
3/28 3.8010
3/29 3.8068
3/30 3.8083
3/31 3.8183
4/1 3.8254
4/2 3.8262
GREWS GREWS
cm Reading
9.4353 38.8247
9.4369 38.82315
9.4391 38.82095
9.4428 38.81725
9.4509 38.8091
9.4629 38.79715
9.4668 38.79325
9.4805 38.77955
9.4954 38.7646
9.5248 38.7352
9.5321 38.7279
9.5510 38.70905
9.5782 38.68185
9.5813 38.6787
9.6091 38.65095
9.6286 38.63145
9.6310 38.62895
9.6546 38.60545
9.6693 38.5907
9.6730 38.587
9.6985 38.5615
9.7165 38.5435
9.7186 38.54145
85


Direct Shear Test
(Shear box 30"x30")
Project No.: 92005 CDOT
Project name: Glenwood Canyon
Material 2" shredded tires
Data: 9/19/1994
Sample No. Normal Stress Shear Stress (Shear @ 20%)
kPa kPa
SHR25 37.2 21.1
SHR275 55.5 34.9
SHR210 73.8 42.7
86


Appendix C
Input data of Finite Element Analysis for 1-D Compression Test
cm min kg One-Dimensional Compression ! 3/28/96
1 0 0 0 0 0
0 0 0 1 0 1
0 0 0 0 0 0 0 0 0
0.001 0. .0
E0 1 0. .032 0.5 1. 223 0.1 669000
669000.
0. .0155 0.492 0. 0155 0.49 0.055
0.00012
0. . 149 0.93 0. 0
1 1 1 1 1 1 1 10.0 1
1 0. 0. 2 43.0 0.
3 0. 9.652 4 43.0 9.652
5 0. 19. 304 6 43.0 19.304
7 0. 28 . 956 8 43.0 28.956
9 0. 38. 608 10 43.0 38.608
E 11 0. 48. 26 12 43.0 48.26
1 1 2 4 3 1
2 3 4 6 5 1
3 5 6 8 7 1
4 7 8 10 9 1
E 5 9 10 i 12 11 1
1 2 1 1
E 3 12 1
1 0 1
1 0 2
1 0 4
2 0 2
2 0 4
3 0 2
3 0 4
4 0 2
4 0 4
5 0 2
5 0 3
E 5 0 4
E 1 11 12 -0 . 125
2 0 0 0 0 0 1 1430.0 1
3 0 0 0 0 1 1 10.0 1
E 1 11 12 -0 . 12
4 0 0 0 0 0 1 1430.0 1
87


5 0 0 0 0 1 1 10.0 1
E 1 11 12 0.12
6 0 0 0 0 0 1 1430.0 1
7 0 0 0 0 1 1 10.0 1
E 1 11 12 0.042
8 0 0 0 0 0 1 170.0 1
9 0 0 0 0 1 1 10.0 1
E 1 11 12 0.024
10 0 0 0 0 0 1 170.0 1
11 0 0 0 0 1 1 10.0 1
E 1 11 12 0.012
12 0 0 0 0 0 1 170.0 1
13 0 0 0 0 1 1 10.0 1
E 1 11 12 0.006
14 0 0 0 0 0 1 170.0 1
15 0 0 0 0 1 1 10.0 1
E 1 11 12 0.0018
16 0 0 0 0 0 1 170.0 1
17 0 0 0 0 1 1 10.0 1
E 1 11 12 0.0024
18 0 0 0 0 0 1 170.0 1
19 0 0 0 0 1 1 10.0 1
E 1 11 12 - 0.0012
20 0 0 0 0 0 1 170.0 1
21 0 0 0 0 1 1 10.0 1
E 1 11 12 - 0.0006
22 0 0 0 0 0 1 170.0 1
23 0 0 0 0 0 1 1440.0 1
24 0 0 0 0 0 1 1440.0 1
25 0 0 0 0 0 1 1440.0 1
26 0 0 0 0 0 1 1440.0 1
27 0 0 0 0 0 1 1440.0 1
28 0 0 0 0 0 1 1440.0 1
29 0 0 0 0 0 1 1440.0 1
30 0 0 0 0 0 1 1440.0 1
31 0 0 0 0 0 1 1440.0 1
32 0 0 0 0 0 1 1440.0 1
33 0 0 0 0 0 1 1440.0 1
34 0 0 0 0 0 1 1440.0 1
35 0 0 0 0 0 1 1440.0 1
36 0 0 0 0 0 1 1440.0 1
37 0 0 0 0 0 1 1440.0 1
38 0 0 0 0 0 1 1440.0 1
39 0 0 0 0 0 1 1440.0 1
40 0 0 0 0 0 1 1440.0 1
41 0 0 0 0 0 1 1440.0 1
42 0 0 0 0 0 1 1440.0 1
43 0 0 0 0 0 1 1440.0 1
44 0 0 0 0 0 1 1440.0 1
45 0 0 0 0 0 1 1440.0 1
88


46 0 0 0 0 0 1 1440.0 1
47 0 0 0 0 0 1 1440.0 1
48 0 0 0 0 0 1 1440.0 1
49 0 0 0 0 0 1 1440.0 1
50 0 0 0 0 0 1 1440.0 1
51 0 0 0 0 0 1 1440.0 1
52 0 0 0 0 0 1 1440.0 1
53 0 0 0 0 0 1 1440.0 1
54 0 0 0 0 0 1 1440.0 1
55 0 0 0 0 0 1 1440.0 1
56 0 0 0 0 0 1 1440.0 1
57 0 0 0 0 0 1 1440.0 1
58 0 0 0 0 0 1 1440.0 1
59 0 0 0 0 0 1 1440.0 1
60 0 0 0 0 0 1 1440.0 1
61 0 0 0 0 0 1 1440.0 1
62 0 0 0 0 0 1 1440.0 1
63 0 0 0 0 0 1 1440.0 1
89


Full Text

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GLENWOOD CANYON GEOSYNTHETIC-REINFORCED SHREDDED TIRE RETAINING WALL b y Sung-Hsing Yu B .S., National Taiwan University 1990 A thesis submitted to the University of Colorado at Denver in partial fulfillment of the requirement for the degree of Master of Science Civil Engineering 2001

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This thesis for th e Master of Science d egree b y Su n g -H s in g Yu h as been a ppro ve d b y John R May s

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Yu Sung-Hsing (M.S. Civil Engineering) Glenwood Canyon Geo syn thetic-reinforced Shredded Tire Retaining Wall Thesis directed by Professor Jonathan T.H. Wu ABSTRACT In October 1994 the Colorado Department of Transportation constructed a geosynthetic-reinforced retaining wall using shredded tires as backfill. The retaining wall was constructed over a landslide area along Interstate Highway-70 near Glenwood Canyon, Colorado. The retaining wall was constructed in 7 tier s with a total height of21 m (70ft). This was, and still is the highest tire-shred retaining wall in the world. The wall was instrumented with survey targets and horizontal inclinometers at strategic locations to monitor its performance during and after construction A study was undertaken to investigate the long-term performance the geosynthetic-reinforced retaining wall. The study was conducted by the finite element method of analysis using a computer model GREWS. The computer model is capable of analyzing the time-dependent performance of an earth structure due to body forces and externally applied loads. Prior to conducting the analysis, the lll

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deformation properties of the shredded tires were investigated. One-dimensional compression tests and direct shear tests were performed using a specially designed apparatus that can accommodate a specimen size of76 em by 76 em by 61 em (30 in by 30 in by 24 in) The measured properties of the shredded tires were used as input to compute the deformed configuration of the wall. The computed deformation was compared with the measured deformation. Very good agreement was observed The analytical model was then employed to predict the long-term performance of the retaining wall. The predicted maximum displacement over 75 years was found to be on the order of 9 1 ft (2.8 m) occurred near the top tier. The retaining wall was subsequently demolished following self-combustion occurred in October 1995. Further research will be needed for future usage of shredded tires in the construction of retaining walls. This abstract accurately represents the content of the candidate's thesis. I recommend its publication IV

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ACKNOWLEDGEMENT I would like to thank Professor Jonathan Wu for his unlimited guidance and encouragement throughout my academic and research program. Also I would like to thank Colorado Department of Transportation for providin g all the materials equipment and information. Finally, I would like to thank my parents my wife and daughters for their unfaltering understanding and support through my study

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CONTENTS Figures. ....... ..... ................... ........ ......... ........... ... ......... .... ............... . ........ ......... 1x Tables ................................. ...................... ........ ............. ... ............ . ...... ... ... ... x1 Chapter 1. Introduction ..... .................. .... ..... .... ............ . .................................. ...... 1.1 Problem Statement .... .. ................ ...... .... .. .. .... .. .. .. .......... .... .. .... .. .. .. .. .. .. .. 1 1.2 Objectives.... ............. ... ............. ........ . ......... ......... .... ..................... ..... 2 1.3 Method of Research ........................ .. ........ ... ........................................... 2 2 The Glenwood Canyon Shredded Tire Test Wall.................................. 4 2.1 Overview......... ........................... ...... ..... ....................... ........... .......... 4 2.2 Pre-Construction Test : Oxford Test Wall ..................... .......... .. ............. 7 2.3 Design and Construction of Glenwood Canyon Test Wall .................... 10 2.4 Monitoring of Wall Performance.. ...................................... ................... 12 2.4 1 Survey Points ..... ....... ..... .............. . ..... . ......... ............. ...... ........ .......... 12 2.4.2 Horizontal Inclinometers........... ........ ... .... ................................... ..... ... 14 3. One-dimensional Compression Test and Direct Shear Test...... ............. 17 3 .1 Test Material................ ... ............................................... ......................... 1 7 3.2 One-dimensional Compression Test.......................... ............ ................ 17 3.2 1 TestApparatus ... ...................... ..... ...................................... ............ ........ 17 Vl

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3.2.1.1 Test Box........................................ .......... ............. . ........ ... ...... ... ..... .... 20 3 .2.1.2 Loading Mechanism............... ..... ........ .................. ............................ .... 20 3.2.2 Measurement and Data Acquisition System...... ........... ........ ............... 23 3.2.3 Sample Preparation and Test Procedure ........... ........ ..... ... ..... . .......... . 23 3 .2.4 Results and Discussions ... .. .. ...... .. .. . . . . . . . .. . .. .. .. ... . . . .. . .. .. ... . . .. 26 3 3 Direct Shear Test.................... ....... ........ .......... . .................... ....... ........ 29 3.3.1 TestApparatus .......... .... ......................................................................... 29 3.3 .2 Measurement and Data Acquisition System .................... . ................... 29 3.3.3 Sample Preparation and Test Procedure.... . ..................... ............. ...... 29 3 3.4 Results and Discussions..... ...... .................................................. . ........ 33 4. Finite Element Analysis............... ................... . ..... ................... ........... 37 4.1 Description of GREWS .............. . ......... .... . ...................... .................... 3 7 4.1. 1 ElementTypesofGREWS ............................ ... .............................. ....... 39 4.1.2 Soil Models......... ............ .............................. .................. .............. ........ 39 4.1.3 Beam and Bar Models ................ ....... ....................................... ............. 42 4.1.4 Interface Model......... .... ........................................................................ 42 4.2 Determination of Material Parameters for Tire Chips........... . .... .......... 43 4 .2.1 Material Parameters of Tire Chips .. .. .. . ...... .. . . ... .. . ... . . . .. . . . . .. . . 4 3 4.2.2 Material Parameters ofFoundation Soil.... ........ .................... .............. . 47 4.2.3 Material Parameters of Facing and Geogrid Reinforcement............ ...... 50 Vll

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4.2.4 Material Parameters of SoilTire Chips Interface..... .......... . .... ........ ... 54 4.3 Finite Element Analysis of the One-dimensional Compression Test..... 55 4.4 Finite Element Analysis of the Glenwood Canyon Test Wall....... . ...... 59 4.4 1 Comparison of Measured Results and Finite Element Analysis Results 61 4.4.2 Predicted Wall Movement of Glenwood Canyon Test Wall.. . ...... ...... 61 5. Summary and Conclusions........ ........... ................. . . ..... . .... ...... ..... . .... 64 5.1 Summary..... ..... ......... ........... ....... ... ..................... ................................ 64 5.2 Findings and Conclusions . . . . . . . . . .. .... .... . ... .. . . .. .. . ... .. . ... . .... .. . 65 Appendix A Survey and Inclinometer Data .......... ..... .... . ..................... . ....... . ........ 68 B. Data of One-dimensional Compression Test and Direct Test..... ............ 81 C. Input Data of Finite Element Analysis for One-dimensional Compression Test .... ... ..... . ................. . ................ ... . ...... . .... ............ 87 D Input Finite Element Analysis Data for Glenwood Canyon Test Wall .... ........... .... ... ...... .... . .... .......... ...... ... ... .... . ....... .............. ........ .... .... 90 References ....... ...... .............. ............. .......... ...................... .............. .................. 11 0 Vlll

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FIGURES Figure 2.1 The Site Appearance Before Construction of the Glenwood Can y on Shredded Tire Test Wall.... . .... ................. ......... ............ .... ..... ............ 5 2.2 The Appearance of the Glenwood Canyon Test Wall after Construction 6 2.3 Design Configuration ofthe Oxford Test Wall...... .... .... . ..................... 8 2.4 The Appearance ofthe Oxford Test Wall.......... . ..... . ...... ................... 9 2.5 The Design Configuration ofthe Glenwood Canyon Test Wall........... 11 2.6 Deformed Configuration ofthe Test Wall............ ............... ................ 13 2 7 Measured Vertical Displacement from Inclinometer Tube A, 3 Months after Construction................................................... ........... .......... . ........ 15 2.8 Measured Vertical Displacement from Inclinometer Tube B 3 Months after Construction. .................. . ....... ...... ......... .... ....... . ............ ........... 16 3 1 Various Lengths and Shapes ofTire Chips ..... ........ ........... ....... . .... ..... 18 3.2 Overall Schematic of One-dimensional Compression Test Apparatus.. 19 3.3 The Test Box...................... ............... ........ ... .... .......................... ............ 21 3.4 Pressure Gauges.......... ...................... ............. .......... ..... . ........ .... ....... . 22 3.5 The Installation ofLVDTs ........ . .................... .............. ....... . ..... ..... .... 24 3 6 Stress-StrainTime Curve for the Tire Chips ... .................. ...... .... .... ..... 27 lX

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3 7 Strain Rate vs. Log (Time) Curve for the Tire Chips ..... .... ........ ....... .... 28 3.8 Overall Schematic of Direct Shear Test Apparatus. .......... ..... .... .......... 31 3.9 The Test Setup for (a) One-dimensional Compression Test and (b) Direct Shear Test ...................... ....... .. ............ ....... ...... ....... ........ ......... 32 3.10 Shear Stress vs Normal Stress. .......... . ....... . ..... .......... ........... ..... ...... 36 4.1 Vertical Strain vs Logarithm of Time in One-dimensional Compression Test .... .................... .... ............... ... ............... .... ...... . ..... ..................... .... 51 4.2 Vertical Strain vs. Square Root of Time in One-dimensional Compression Test......... ..... ....... .... . ..... ......... ............. .... ........ ............. 52 4 3 Tire Blocks. ................... ................ .......... ..... ............ ..... ...................... 53 4.4 The Finite Element Mesh for One-dimensional Compression Test.... ... 57 4.5 The Comparison of the Creep Behavior of Tire Chips from GREWS Analysis and One-dimensional Compression Test................................. 58 4.6 Finite Element Mesh for Glenwood Canyon Test Wall................... ..... 60 4.7 Comparison of Measured and Finite Element Analysis Result.............. 62 4 8 Predicted Wall Movement after 75 Years of Glenwood Canyon Test Wall......... .............. ..... .................. .... ..... ..... .... ....... ........ ............... ...... 63 X

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TABLES Table 3.1 Data for the Dial Gauge Vertical Stress and Actual Vertical Stress at Failure.... ...... .... .... .... . ............. . ......... .... ................. ... ... ..... ...... . .... .... 3 4 3.2 The Vertical and Horizontal Stresses at Failure Using Corrected Areas 35 4 1 Material Parameters for Sekiguchi-Ohta Model...... ............... .......... .... 49 4.2 Properties of Foundation Soil.... .. ................ ... . ........... .......... .... .... .... 49 4 3 Material Paramet e rs for Foundation Soil .......... .... ........ .... ............... .... 49 4.4 Material Parameters for Beam Elements. ....... ...... ..... . ..... ..... ............ . 50 4.5 The Input Geogrid Parameters for Bar E lements.. .... . ..... . ......... ..... .... 50 4 6 The Input of the Interface Paramet ers.... . .......................... ................. 54 4.7 The Adjusted Input Parameter s for Tire Chips............ ............. ..... ....... 56 Xl

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1. Introduction 1.1 Problem Statement Over two billion waste tires are sitting in stockpiles across the U .S., and more than 240 million waste tires are being discarded each year (Main e Department of Environmental Protection (DEP) 1989 ; Eaton et al. 1991 ; Stark and Korte 1988). Disposal of these waste tires has become an acute environmental problem because of its fast increasing volume Although tires are classified as a nonhazardous waste their disposal presents fire hazards and pollution problems Serious tire fires have been reported in Texas Virginia, Washington and Florida (Maine DEP 1989). These fues were difficult to extinguish and typically lasted several months They also produced toxic air and toxic oil by products. In mid-1960s, an alternative disposal method for waste tires began in the asphalt pavement construction Ground tire rubber was blended with hot liquid asphalt as highway pavement material (Eaton, et al., 1991). In recent y ears waste tires are cut into chips (referred to as shredded tires or "tire chips ) of various sizes to reduce their disposal volume. Shredded tires have many desirable characteristics in engineering applications The y are durable 1

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lightweight, and free draining; therefore, they can be a viable substitute for soil in the construction of earth structures such as retaining walls. Only recently have attempts been made by researchers in Maine and Wisconsin to use shredded tires in retaining wall construction (Maine DEP 1989). In October 1994 the Colorado Department of Transportation constructed a 21 m (70ft) high retaining wall using shredded tires as backfill. The retaining wall was constructed over a landslide area and is located in Glenwood Canyon, Colorado along Interstate Highway-70. To the author s knowledge, this is the highest tire-shred retaining wall in the world. 1.2 Objectives The objectives of this study were two-fold. The first objective was to determine engineering properties of shredded tires. The second objective was to predict the long-term performance of the Glenwood Canyon tire chip test wall. 1.3 Method of Research To predict the long-term performance of the Glenwood Canyon tire chip test wall the finite element method of analy s is was employed. A computer program GREWS (Qeosynthetic-REinforced Wall and was used for the analysis (Wu, et al., 1994 ). The program is capable of simulating long-term creep of the tire chips 2

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and determining the long-term performance of the test wall. Direct shear tests were performed on tire chips. Since the chips are fairly large in size (nominal width= 2 in.), a large direct shear apparatus was manufactured to conduct the tests. The test box was also used to conduct a one-dimensional long term compression test for the tire chips 3

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2. The Glenwood Canyon Shredded Tire Test Wall This chapter g i v es a brief overview of the Glenwood Canyon shredded tire wall and describes the design and construction of test wall. In addition the monitoring system including the survey points and horizontal inclinometers, which were installed during construction is presented. 2.1 Overview In 1930s two lanes of the U.S. Highway 6 was built through the Glenwood Canyon Colorado. The construction resulted in a number of erosional scars along this highway. In the 1980s the two-lane highway was expanded into four lands becoming part of Interstate Highway-70. There was an agreement between the Colorado Department of Highways (CDOH) and the Environmental and Citizen Group prior to the reconstruction of the road to repair the erosional scars (Bell et al. 1983) The instabilities of the scars near the Hanging Lake rest station about 12 miles east of Glenwood Springs, have been a concern for highway safety In the early 1990s the CDOH began to remediate the slopes. After evaluating alternatives the CDOH decided to employ a lightweight fill retaining wall system with a s loping top 4

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surface cover the scars The Glenwood Canyon shredded tire test wall was constructed from October 1994 to February 1995. Figure 2.1 shows the appearance ofthe Glenwood Canyon test wall site before construction. Figure 2 2 shows the Glenwood Canyon test wall after construction. Figure 2 1 The Site Appearance before Construction of the Glenwood Canyon Shredded Tire Test Wall 5

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Figure 2.2 The Appearance of the Glenwood Canyon Te s t Wall after Construction 6

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2.2 Pre-construction Test: Oxford Test Wall In June 1994 CDOT constructed a small tire chip GRS test wall prior to construction of the Glenwood Canyon wall. This test wall was referred to as the Oxford test wall. Figure 2.3 depicts the design configuration of the Oxford test wall. This test wall had one tier, which was about 3 m (10 ft) tall. The area was approximately 20 m (60 ft) long and 6 m (18 ft) high. The wall face consisted of compressed tire blocks which weigh about 113 of concrete. The backfill was large size shredded tires. The shredded tire backfill is about 1/4 the weight of soil. No anchors were used, and the backfill was reinforced with layers Tensar 1400 geogrid at 60 em (2ft) vertical spacing. Figure 2.4 shows the appearance of the Oxford test wall. The survey points were installed to monitor the performance of the test wall after construction. A total of 20 survey targets were installed. The survey targets were mounted on the wall face in a somewhat uniformly distributed pattern. 7

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Front View 3m 6.1 m I 2 3 Instnnnentation Layout -number points are survey reflectors Side View Tensar UX 1400 Shredded Tire Backfill ..__2.1 m--" Existing Ground Surface Reinforcement Layout Figure 2.3 Design Configuration of the Oxford Test Wall 8

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Figure 2.4 The Appearance of the Oxford Test Wall 9

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2.3 Design and Construction of Glenwood Canyon Test Wall The engineering design for the Glenwood Canyon test wall was perform e d by John Kliethermes Jr. and constructed by Service Engineering Inc. This test wall had 7 tiers with each tier about 3 m (1 0 ft) tall. The area was appro x imately 100m (300ft) long and 30m (90ft) high. The wall face consi s ted of compressed tire blocks and the backfill was shredded tires (5 em (2 in ) tire chips) in th e top 5 tiers The backfill in the bottom 2 tiers was on site soils. No anchors back into the hillside were used and the backfill was reinforced with layers T ensar 1400 geogrid at 60 em (2 ft) vertical spacing. Figure 2.5 depicts the design configuration of the Glenwood Canyon test wall. The total estimated cost for this project was approximately $750 000. This is about 113 the cost of a traditional concrete retaining solution which would require lon g soil anchors for stability due to the weights o f concrete and s oil backfill (Barrett 1995) 10

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_. _. Scale 0 2 4 6 Tier 1 8 10m Tier 5 / Soil Backfill Shredded Tire Backfill \_Existing Gmund SuiToo< Figure 2.5 The Design Configuration of the Glenwood Canyon Test Wall

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2.4 Monitoring of Wall Performance The survey points and inclinometers were installed to monitor the performance of the test wall during and after construction. A total of 112 survey targets and four horizontal inclinometers were installed The survey targets were mounted on the wall face in a somewhat uniformly distributed pattern. The inclinometers were embedded at the bottom of the 3rd and 5th tiers. 2.4.1 Survey Points Figure 2.6 shows the displacement profile near the center section of the test wall 7 months after construction as measured by the survey points. The maximum wall displacement was about 138 em (4.5 ft) outward and 109 em (3.6 ft) downward and occurred at the top after sixth tier. The measurement data of survey points are presented in Appendix A. 12

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Scale 0 2 w 4 6 8 10m Maximum Displacement De s ign Configuration 7 months Figure 2.6 Deformed Configuration of the Test Wall

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2.4.2 Horizontal Inclinometers Figures 2. 7 and 2.8 show the result of inclinometer tubes A and B respectively. Inclinometer tube A was located at the center section of the third tier and inclinometer tube B, also installed in the third tier, was located at 5 m (15ft) to the right of tube A. The last set of data was taken 3 months after construction due to a very large displacement, which bent the tube very significantly. The largest displacement 3 month after construction was about 73 em (29 in.) in tube A, and 59 em (23 in.) in tube B, both occurred near wall face. The displacement decreased approximately linearly toward the back of the wall. Inclinometer tubes C and D were located at the fifth tier. The last set of data was taken about 1 month before the end of construction. Because of large displacements tube C and D deformed substantially, it was not possible to insert the inclinometer probe in the tube for measurement. The measurement data of the inclinometers are also shown in Appendix A. 14

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,.--..._ 8 (.) ...__, 0 c: -20 Q) 8 Q) (.) -40 0.. Cll a -60 .... ...... ....... Q) > -80 0 100 Tier 3 Center Section 200 300 400 500 Distance from Wall Face (em) Figure 2.7 Measured Vertical Displacement from Inclinometer Tube A 3 Months after Construction 15

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0 ,...-._ 8 (.) ';:: -20 s:: 8 (.) -40 a Tier 3, 5 meter to the Right of Center Section -60 ----------> -80 0 100 200 300 400 Distance from Wall Face (em) 500 Figure 2.8 Measured Vertical Displacement from Inclinometer Tube B 3 Months after Construction 16

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3. One-dimensional Compression Test and Direct Shear Test A one-dimensional compression test was conducted to determine time dependent deformation of the tire chips. Direct shear tests were conducted to determine the friction characteristics of the tire chips. The tests were conducted using a test apparatus designed and manufactured by the Colorado Transportation Institute (CTI). 3.1 Test Material The tire chip tested is referred to as 5 em (2 in.) tire chip, implying that the maximum width of the tire chip is 5 em (2 in.). The length of the chips typically varies between 2 5 em (1 in ) and 15 em (6 in.). Typical thickness is 0.8 em (0.3 in.) with some containing a steel belt sandwiched at the middle Figure 3.1 shows various lengths and shapes of the tire chips. 3.2 One-Dimensional Compression Test 3.2.1 Test Apparatus As shown in Figure 3 2 the test apparatus consists of a test box a pulley frame arrangement and a data acquisition system The pulley-frame arrangement 17

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was used to hoist the components of the test apparatus during assembly and disassembly. Figure 3.1 Various Lengths and Shapes of Tire Chips 18

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Scale Pressure Gauges _. \0 Data Acquisition System Figure 3.2 Overall Schematic of One-dimensional Compression Test Apparatus

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3.2.1.1 Test Box The test box for the one-dimensional compression test consists o f a lower bo x an upper box, a sliding block and a top cap as is shown in Figure 3.3 The top box is 76 em (30 in.) in length 76 em (30 in.) in width and 41 em (16 in.) in height the bottom box has the same length and width as the top box but its height is 20 em (8 in .). The side walls in the interior of the test box were lubricated to minimize side wall friction upon load application. The lubrication was achieved by placing a latex membrane between the internal side wall of the test box and the test material (i.e. tire chips) A uniform layer of silicon grease was applied to the surface of internal side walls before placement of the membrane. Such a technique has been shown to reduce the friction angle to 1 degree (Tatsuoka et al. 1984). 3.2.1.2 Loading Mechanism The vertical load was applied by pneumatic pressure applied to the top surface of the tire chips The pressure was exerted by using an air bladder which was fitted inside the upper box between the top cap and the sliding block (see Figure 3.3). Three gauges were used to monitor the air pressure (see Figure 3.4). 20

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Sliding Block 40 6 em Upper Box -+ 20 3 I 7-=----::-:-=----L. 76.2 em / Figure 3.3 The Test Box 21 --.---

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To Air Bladder-------. Figure 3.4 Pressure Gauges 22

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3.2.2 Measurement and Data Acquisition System Two Linear Voltage Displacement Transducers (L VDT) were used to measure the compression of the tire chips. The sensing rod of the L VDT was in contact with a blade extruding through a narrow slot outside of the test box from the sliding block (see Figure 3.5) A personal computer equipped with an electronic board was connected to the L VDT to record the digital data which were converted from voltages read by the L VDT through an electronic board. The computer program used to collect the data is called KEITH. The data acquisition system has 5 channels which could be connected to L VDT' s or load cells. In the one-dimensional compression tests, readings were taken at 1 0-minute intervals. 3.2.3 Sample Preparation and Testing Procedure The procedure of sample preparation and testing can be described by the following steps: 1 Place the upper box directly over the lower box and securely clamp the 2 boxes. 2. Lubricate side walls: Apply a thin layer of Shin-Etsu Silicone grease on internal side walls by using a brush. 23

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LVDT LVDT Figure 3 5 The Installation ofLVDTs 24

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3 Place a layer of latex membrane on the side wall: The size of membrane needs to be slightly larger than the side wall to prevent direct contact of the tire chips with the side wall 4 Place the tire chips inside the text box: Separate a total weight of tire chips of 179.8 kg (396lbs) into 3 equal parts Each part of the tire chips was placed inside the test box and compacted to the desired density It was found that compacting tire chips was very different from compacting soils After removal of the compaction load, the tire chips tend to rebound The modified Proctor with 4.5 kg (10 lbs) hammer was not efficient for compaction because of the elasticity of the tire chips. It was found that a person jumping up and down on the surface with the help of a metal rod poking the chips produced fairly efficient compaction After 3 layers of compaction the total height of the test samples in the test box was 48.3 em (19 in ) and the unit weight ofthe tire chips was 6.3 kN/m3 (40 pet) 5 Set the sliding block on the top surface of the tire chips 6. Install the air bladder on top of the sliding block. 7 Assemble the top cap and lock off the steel posts to secure the boxes. 8 Install the LVDT as described in Section 3.2.2 9 Install the pressure supply system and data acquisition system 10. Begin the test: The pressure in the air bladder was applied in four increments 25

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over a period of four days. An equal increment of 13.8 kN/m2 (2 0 psi) was applied in the first 3 days. On the fourth day, an increment of 10. 3 kN/m2 (1.5 psi) was applied which brought the total pressure to 51.7kN/m2 (7.5 psi) Thereafter the pressure was maintained at 51.7kN / m2 (7.5 psi) for 42 days. Readings of compression were taken at 10 minutes intervals for the first 7 days. Thereafter the interval of reading was 1 day. 3.2.4 Results and Discussions The purpose of the one-dimensional compression test was to determine the load-deformation behavior of the tire chips which was needed for finite element analysis. In addition a long term compressibility test was performed to determine creep characteristics of the tire chips under a sustained load. The test data presented in this chapter were tabulated in Appendix B Figure 3 6 shows the relationships of strain elapsed time and vertical stre ss. The strain is calculated based on the vertical displacements as the average of the 2 L VDT measurements. The strain-tim e curve shows the creep behavior under a vertical stress of 51.7 kN/m2 (7.5 psi). It should be noted that the deformation continued to occur when the test was terminated 26

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N -....J 2 f1t 1'1 /rtl ) StreSS Strain(% ) 20 10 2o 3o Figure 3.6 Stress-StrainTime curve for the tire chips 40 s 0 6 l'irne I 1 oo o 0 (tnin)

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Figure 3 7 illustrates the strain rate versus logarithm of time. The curve shows that the strain rate decreases with time at decreasing rate At the end the test period of60, 000 minutes (42 days) the strain rate was 0.2964x10 -5 /min. V) 0 ><: : s E '-' Q) ..... ell 1-< c: c; t: r:/J One-dimensional Compression Test 16 14 ' .. .. ----------. ------... ---. -----------------.--------------. ------' ' ' ' ' . ' 12 -. . --. ---.----.. ---.... ---... ---.. -.... -... -. ..... -----.--.--.. ._.... -----.. -.. I I o o o o o o o I I o 0 o o 0 o o 0 ' ' . ' ' ' ' ' . I I o o o o o o o 10 I o o o o o 0 o o ------------________ _, ______ .. ____ .. ___ .. __ ... __ _. _ .. _____ _____________ .. ________ ---------' . .. ' . ' ' ' ' ' ' ' ' . 8 o o o I o o I J J I. l L J J l.J l .. I o 0 o o o o o o o I I I I o o I o I I I I o o o I o o o I I I o o o I o o I I I I o o o 0 o o ' ' ' ' 6 ' ' ' ' ' ' ' ' ' -------------;----------r-rr-,---,--;--,------------r-------------, ' ' ' ' ' ' .. ' ' ' ' I o I I I I 4 -----------.. --------.---.--.----.--... --,--.--.--------------,.------------------2 0 1 000 0 ' ' ' ' 0 ' ' ' ' ................. .., .... ,. ... ,. . r-.-. .. ' .. . .. ... ' ' ' 10, 000 100, 000 log (tim e ) (min) Figure 3.7 Strain Rate vs. Log (Time) Curve for the Tire Chips 28

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3.3 Direct Shear Test 3.3.1 Test Apparatus The test apparatus used in direct shear tests was the same as that used in the one-dimensional compression test as described in Section 3 .2.1, except that : The lower bo x was attached to a hydraulic jack and was allowed to move horizontally relative to the upper box (see Figure 3.8). A load cell was mounted to measure the horizontal force transferred to the upper box (see Figure 3 8). 3.3.2 Measurement and Data Acquisition System The measurement and data acquisition system was the same as that described in Section 3 .2.2 for the one-dimensional compression test except that a L VDT was added to measure horizontal displacement of the lower bo x as the shear force was being applied 3.3.3 Sample Preparation and Test Procedure Per AASHTO designation T236-84 Direct Shear Test of Soil Under Consolidated Drained Conditions ," the width of direct shear box should be at least twice as the height and the height of the box should be at least six times the soil 29

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grain size (AASHTO 1986) For the 5 em (2 in.) tire chips the size oftest box is deemed adequate Sample preparation and data acquisition followed essentially the same procedure as that described in Section 3.2.3 Th e testing procedure can be described by the following steps : 1 A load cell was set to recording the horizontal force. The hydraulic jack was set to push the lower box at a constant displacement rate of2.5 em/min (1 in ./ min) speed 2. Three different vertical stresses were applied to the specimen. Th e first test was conducted under 34.5 kN/m2 (5 psi) of vertical stress the second at 51.7 kN/m2 (7.5 psi) vertical stress and the third at 69.0 kN/m2 (10 psi) vertical stress. 3. Remove the clamps which were employed to fixed the upper box and lower box during preparation of the sample then start the test. A comparison of the test setup between the one-dimensional compression test and direct shear test is shown in Figure 3.9 4 The tests were terminated when the horizontal movement reached 15.2 em ( 6 in ) (i .e., 20% of the length of the sheer box) 30

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w ........ Pulley Scale 0 Air 0.5 1m Sliding Block Steel Post Top Plate Pressure Gauges c=::J Hydraulic Jack Data Acquisition System Figure 3.8 Overall Schematic of Direct Shear Test Apparatus

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Clamp Upper Box Lower Box (a) Upper Box (Affixed) Lower Box I (b) Clamp Shear Force Figure 3.9 The Test Setup for (a) One-dimensional Compression Test and (b) Direct Shear Test 32

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3.3.4 Results and Discussions The AASHTO (1986) designation T236-84 Direct Shear Test of Soil Under Consolidated Drained Conditions specifi e s that failure occur s wh e n the horizontal displacement reaches to 10% of the length of bo x This specification is for those direct shear tests that cannot achie v e a peak shear stress such as tire chips The vertical stress was applied by pneumatic pressure which had been calibrated by Mr. Ruckman ofCDOT. The calibration equation is: crA= 0 .85 cro + 437 1 where crA= Calibrated applied pressure N / m2 cro= Applied pressure (from pressure gauge) N/m2 (3.1) Table 3.1 shows the relationship between the applied and calibrated pressures used in the tests. 33

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Table 3.1 Data for the Dial Gauge Vertical Stress and Actual Vertical Stress at Failure Applied Pressure (from Calibrated applied pressure cr A Pressure gauge) cro (kN/m 2 ) (kN/m2) 34.5 (5 psi) 29.7 (4.3 psi) 51.7 (7 5 psi) 44.4 (6.4 psi) 69.0 (10 psi) 59.0 (8.6 psi) Note: crA= 0.85 cr0 + 437 1 The contact area between upper and low er boxes decreases during the test. To determine the stresses in the soil, the actual contact area (corrected area) should be used. The corrected area can be calculated as : A c = Wx(L-2d) (3.2) In which, W is the width of the shear box L is the length of the shear box, and d is the displacement. Using the corrected areas, the vertical and horizontal stress can be calculated, as shown in Table 3.2. It is noted that the horizontal stresses were determined as the displacement reached 10% of the box length per AASHTO T23684. 34

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Table 3.2 The Vertical and Horizontal Stresses at Failure Using Corrected Areas Corrected Area Vertical Stress Horizontal Stress A c (m 2 ) cro (kN/m 2 ) 't (kN/m2) 0.465 (720 in ? ) 37.2 (5.39 psi) 21.1 (3.06 psi) 0.465 (720 in ? ) 55.5 (8.05 psi) 34 9 (5.06 psi) 0.465 (720 in. 2 ) 73.8 (10.7 psi) 42.7 (6.19 psi) Figure 3.10 shows the Mohr-Coulomb failure envelope. The strength parameters were : internal friction 30 .5, and cohesion C = 0.2 kN/m 2 (4.4 psf) Humphrey et al (1992) reported strength parameters of various tire chip in the range 19 to 25 and C = 7.66 kN/m2 (160 psf) to 11.49 kN/m 2 (240 psf) The tire chips in their study was generally smaller in size, and the test apparatus measured was 30 em by 30 em (12 in. by 12 in.). 35

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,.-... "' E ---..__, en en Q) $-, ...... [/) Q) ...c: [/) 100 80 60 40 20 0 0 Direct Shear Test C = 0. 2 kN/ m2 = 30.5 ' ----------_,_-----------!------------. ' ' ' ' ' ' ' ' ' ' -.----------1------------' ' r-. ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' 20 40 60 80 Normal Stress (kN/m2 ) Figure 3.10 Shear Stress vs. Normal Stress 36 100

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4. Finite Element Analysis A finite element computer code, GREWS, was selected for analyzing performance of the Glenwood Canyon tire shred wall. The computer program was developed by Wu, et al. (1994) on behalf of CTI and CDOT. This chapter describes the analytical model GREWS, determination of material parameters, analysis of one-dimensional compression tests, and condition analysis of the Glenwood Canyon test wall. 4.1 Description of GREWS GREWS is a comprehensive analysis and design tool for geosynthetic reinforced retaining walls and steep slopes. The program GREWS was derived from a finite element program DACSAR, an acronym for Deformation Analysis Considering .S.tress Anisotropy and Reorientation. The program DACSAR was developed by Iizuka and Ohta (1987) at Tokyo University, Japan The program GREWS has four levels of sophistication (Wu, et al., 1994): Level-l: Empirical Design Level-l is for design only. It can be used for design of geosynthetic reinforced retaining walls using limit equilibrium methods, including the 37

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U S Forest Service ultimate-strength method AASHTO ultimate-strength method and the CTI service-load method. Level-2 : Automated Design or Analysis Level-2 can be used for analysis and design of geosynthetic-reinforced soil walls in a variety of different conditions. A set of different automated finite element meshes has been utilized to accommodate geosynthetic reinforced soil walls of different heights, different backfills, different foundations and different retained soil conditions. Level-3 : Semi-Automated Design or Analysis Level-3 allows the user to make modifications to the input of Level-2 design or analysis; moreover it can be used in situations where the user wants to specify the material properties. Level-4: Standard Finite Element Analysis Level-4 uses standard finite element method for analysis of geosynthetic reinforced soil walls. As a result the user need to input the finite element mesh, the material properties the boundary conditions the loadings and construction sequences. In this study, Level-4 was used for the analysis of the geosynthetic-reinforced tire shred retaining wall. 38

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4.1.1 Element Types of GREWS GREWS incorporates the following elem e nt types (Wu et al. 199 4) : (1) Soil element: Soil elements are four-node quadrilateral elements. Each node has 2 degrees of freedom (horizontal and vertical displacements) (2) Beam element: Beam elements are two-node straight line elements with ( 3 ) Bar element : axial shear and bending stiffn e ss Bar elements are two-node straight-line elements with axial stiffness only. (4) Interface element: The interface elements are four-node elements Each 4.1.2 Soil Models interface element consists of 2 linear elastic perfectly plastic springs (normal and shear springs) which control the displacement between the interface of 2 materials. GREWS has 3 soil models a linearly elastic model a nonlinear elastic hyperbolic model and an elasto-viscoplastic model. The elasto-viscoplastic model incorporated in GREWS is Sekiguchi-Ohta model (Sekiguchi and Ohta 1977). This model is capable of simulating the time-dependent and time39

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independent parts of elasto-viscoplastic soils. For the time independent model the soil parameters needed are A, crv; ko, kx/Yw, ky(z/Yw, ei and Ak. The following are the meaning of each parameter. Lame's constant Lame's constant effective overburden pressure in-situ ko : coefficient of earth pressure at rest coefficient of permeability in x(y) direction at the reference stress state coefficient of permeability in y(z) direction at the reference stress state initial void ratio in-situ gradient of e plotted against ln(k) The time-dependent part of the model was used in this study for simulation of the tire chips. The parameters needed in this model are D, A, M, u, , kx
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A: M: u' : ko : k;: a : dv0/dt A.: eo (1963) irreversibility ratio expressed as A=l-(k/A.) critical state parameter effective Poisson's ratio coefficient of permeability in x(r) direction at the reference stress state coefficient of permeability in y(z) direction at the reference stress state preconsolidation pressure coefficient of earth pressure at rest effective overburden pressure in-situ coefficient of in-situ earth pressure at rest coefficient of secondary compression initial volumetric strain rate at reference state expressed by dvo /dt =a/ tc where tc is the time at end of primary consolidation compression index in the e -ln(p'/p0 ') relationship void ratio corresponding with avo' at 41

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reference state gradient of e plotted against ln(k) plot 4.1.3 Beam and Bar Models The stress-strain behavior for both beam and bar elements is assumed l i nearl y elastic in thi s study The properties E A and I are s pecified for each beam element, whereas the properties E and A are specified for each bar element. Output includes displ a cement s, moment trust and shear for beam e lements displacements and tru s t for bar element. The following are the meanin g of the parameters E: A: I : 4.1.4 Interface Model Young s modulus ofbeam or bar cross-sectional area moment of inertia of area The interface model was similar to the type proposed by Goodman, et al. (1968) based on the method of stiffness. Two linear spring constants kn (normal stiffness) and k s (shear stiffness) are used to simulate th e interfac e b e havior in normal and tangent direction The parameters for the interface model are kn, k5 crv , k ;, c and 42

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The following are the meaning of the parameters. normal stiffness shear stiffness overburden pressure coefficient of in-situ earth pressure at rest c: cohesion tangent of angle of internal friction 4.2 Determination of Material Parameters for Tire Chips 4.2.1 Material Parameters of Tire Chips Some properties of tire chips were determined from results of onedimensional compression tests and direct shear tests, others were by empirical correlation. The time dependent parameters of Sekiguchi-Ohta model (Sekiguchi and Ohta, 1977) can be determined as follows: From the direct shear test, therefore, M = 43 (4.1)

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M = 1.22 And ko =1= 0.492 For one-dimensional compression tests, the mean stress is: Since Therefore cr1 + 2 x cr3 p =----3 0"3 = koX 0"1 = 0.492xcr1 p = 0.661 X O"I (4.2) (4.3) The initial void ratio can be computed by the following equation (Sekiguchi and Ohta 1977) (4.4) where y0 is the compacted unit weight of tire chips which was 6.3 kN/m3 ( 40 pet); G s is the specific gravity of tire chips which was 1.24 (Humphrey et al. 1992) ; 44

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and Yw is the unit weight of water which was 9.81 kN/m3 (62.4 pet). The initial void ratio of the compacted tire chips was determined to be 0 .93. Choosing a data point (point a) from the stress-strain curve for the tire chips Ea = 0.0768 and cra = 12.4 kPa (or 1.8 psi) therefore, P a = 0.661 x cr2 = 8.2 kPa (or 1.2 psi) The compression box measures, 76 2 em (30 in ) in width and length and 48.3 em (19 in.) in height thus the surface area was 0 .58 m2 (900 in.2 ) and the volume was 0 .28 m3 (17,100 in .3 ) From 1-D compression test, M = 3.71 em (or 1.46 in.) thus, Since and therefore, ,1.V= M Area= 0 022 m3 (or 1314 in .3 ) e = V v = 0.93 V s (4.5) (4.6) Choosing another test data point (point b) from the stress-strain curve for the tire chips 45

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Using the above procedure Since thus, Assuming thus,
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determine the value a. However, instead of plotting displacement versus logarithm of time the vertical strain versus logarithm of time was plotted in Figure 4.1. The coefficient of secondary compression a, is the slope of the secondary compression curve which is equal to 0 00058. The initial volumetric strain rate can be calculated by dv0/dt = a/ to where tc=t9oThe Taylor's square root of time fitting method was applied to obtain t9o, which was equal to 31,500 min (see Figure 4.2 for vertical strain versus square root of time plot) Therefore dvo /dt = 1.8x 108 min -1 The kx(r) and k y(z) the coefficients of permeability were assumed to be the average value obtained by the permeability test conducted by Humphrey et al. (1992). Both kx(r} and ky(z) were assumed to be equal to 11.15 cm/s (4.4 in./s). The unit weight oftire chips in the one-dimensional compression test is 6.3 kN/m3 (40 pcf) and the height of the sample was 48.3 em (19 in); therefore, the average I effective overburden pressure ( crv ) was 1.5 k.Pa (0.22 psi) Table 4.1 1 summarizes the Sekiguchi-Ohta material parameters of the tire chips. 4.2.2 Material Parameters of Foundation Soil According to the foundation report for uphill retaining walls at Shoshone Dam in Glenwood Canyon published by the Colorado Department of Highways, a 47

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depth from 0 to 6.1 meter (20 ft) consists of colluvial nature and primarily of talus in a matrix of sandy gravel with scattered cobbles and boulders (Bell, et al., 1983). Some soil propertie s were selected based on the soil type The unit weight, Young's modulus (E) friction angle ( ) Poisson's ratio ( v ), coefficient of permeability (k), and initial void ratio ( e0 ) of the soil are shown in Table 4.2 Using the equations, -:;= ___ v__E__ d E A an (1 + v )(1-2v) f.1 = 2(1 + v) therefore = 80.64 kg/ cm2 (or 1147 psi) ii = 25.5 kg/ cm2 (or 362 psi) The unit weight of soil was 15.7 kN/m3 (100 pcf) and the height of a tier was 3.05 m (10ft); therefore, the average effective overburden pressure ( crv1 ) was 23. 9 kPa (500 psf). The linear elastic soi l parameters of the foundation soil are shown in Table 4.3. 48

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Table 4.1 Material Parameters for Sekiguchi-Ohta Model I 0 015 kg/cm2 (1.5 kPa) D 0.036 crv, A 0 5 k i 0.49 M 1.22 a 0 00058 v 0 1 dv0/dt 1 8 X 1 0-S minI kx(r/Y w 11.15 cm/syw A 0.17 k y(z/ Y w 11.15 cm/syw eo 0.93 I 0.015 kg/cm2 (1.5 kPa) O"vo Ak 0.17 k o 0.49 2 Table 4.2 Properties ofFoundation Soil y 0.0016 kg/cm3 (100 pcf) \.) 0.38 E 70.31 kg/cm2 (1000 psi) K 0.01 cm/s 40 eo 1.0 Table 4 3 Material Parameters for Foundation Soil A 80 64 kg/cm2 kx(r/Y w 0.01 cm/syw J..l 25.5 kg/cm2 k y(z/ Yw 0 .01 cm/syw I 0.24 kg/cm2 O"v; ei 1.0 ko 0.357 Ak 0 49

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4.2.3 Material Parameters of Facing and Geogrid Reinforcement In the finite element analysis, the wall face was simulated by a series of beam elements and reinforcement by a series of bar elements. The wall face was comprised of tire blocks which were made of melted compressed tires. Each tire block measures approximately 122 em (4ft) long 61 em (2ft) high, and 45.7 em (1.5 ft) wide (see Figure 4.3) Tensar UX-1400 geogrid was installed at 61 em (2 ft) vertical spacing. The material parameters of the beam and bar elements are shown in Table 4.4 and Table 4 5 Table 4.4 Material Parameters for Beam Elements E 281 kg/cm2 ( 4000 psi) A 116.1 cm2 (18 in2 ) I 20200 em 4 ( 486 in 4 ) Table 4.5 The Input Geogrid Parameters for Bar Elements. E 1.4 kg/cm2 (20 psi) A 50

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17.0% 17.1% 17.2% 'C[( '--" c: 17.3% "@ !::3 r:/) 17.4% 17.5% 17.6% 1,000 10,000 100,000 log (time) (min) Figure 4.1 Vertical Strain vs. Logarithm of Time m One-dimensional Compression Test 51

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17.1% 17.2% ------------17.3% '-" 1:::1 "(ii 1-; ...... r:/) 17.4% 17.5% -------------0 50 100 150 200 250 Figure 4.2 Vertical Strain vs. Square Root of Time in One-dimensional Compression Test 52

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Figure 4.3 Tire Blocks 53

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4.2.4 Material Parameters of Soil-Tire Chips Interface Two linear spring constants k5 (shear stiffness) and kn (normal stiffness) were used to simulate the interface behavior on tangent and normal directions at the soil-tire chip interface The k5 was the slope of the shear stress versus relative displacement curve and was assumed to be 112 of the initial k5 value of the tire chips alone The kn was assumed to be a large" value in order to prevent penetration of the contacting nodes. The friction angle was assumed to be 2 / 3 of the internal friction angle of the tire chips and the cohesion of the interface was assumed to be 1 /2 of the cohesion of tire chips The coefficient of in-situ early pressure at-rest ki was calculated as ki = 1 The unit weight of tire chips was 6.3 kN/m3 ( 40 pet) and the average height of backfill was 4.7 m (15. 5 ft ), hence the o v erburden pressurecrv, was 29.7 kPa (620 psf) The material paramet e rs of interface model ar e shown in T a ble 4.6. Table 4 6 The Input of the Interface Parameters k s 0.0038 kg/cm3 kl 0 .653 kn 1 000,000 kg/cm3 c 0 O"v; 0.3 kg/cm2 0.371 54

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4.3 Finite Element Analysis of the One-Dimensional Compression Test The purpose of this study was to determine engineering properti es of the tire chips and to predict the long-term performance of the Glenwood Canyon tire chip test wall. It was assumed that the material characteristics of the using the soil tire chips are similar to those of soils; as a result some property tests were conducted testing methods. The data resources for tire chips are very limited hence it was necessary to perform some property tests for the tire chips. However the test results might vary under different test conditions. For example different apparatus size of tire chips and temperature may significantly change the properties of the tire chips Therefore, back analysis was needed to determine properties of the tire chip in finite element analyses. GREWS was fust used to simulate the onedimensional compression test. The main purpose of the analysis was to make adjustments of the input parameters for tire chip properties. The strain versus time curve as shown in Figure 3.6 for the tire chips was used for the back-analysis. The simulation of one-dimensional compression test assumed the test box was in an axi-symmetric condition The radius of the equivalent cylindrical box was computed by 1t x r2 = A where r is the equivalent radius and A is the total area of the test box which is equal to 0.58 m2 (900 in ? ) ; therefore r is equal to 43 55

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em (16.9 in.). A finite element mesh was established as shown in Figure 4.4 The mesh includes 5 quadrilateral elements and 12 nodes. Material parameters listed in Table 4.1 were first used in the analysis of the one-dimensional compression test. The results were compared with Figure 3.6. The input data for this analysis are shown in Appendix C. Figure 4 5 shows a comparison of the creep curves obtained from GREWS analysis and the actual test. It is noted that the analysis shows a slightly smaller instantaneous strain (about 0.2 % lower) than the measured value. However, the creep behavior is almost identical. The adjusted material parameters of the tire chips are shown in Table 4 7 These adjusted parameters of the tire chips were used in the finite element analysis for the Glenwood Canyon tire chip test wall. Table 4.7 The Adjusted Input Parameters for Tire Chips I 0.015 kg/cm2 1.5 kPa) D 0 036 O"v; 0.5 k; 0.49 M 1.22 a 0 055 v 0.1 dv0/dt 1.2 x 10-4 min-1 kx(r/Yw 11.15 crnlsyw 'A 0.17 ky(z / r w 11.15 crnlsyw eo 0.93 I 0.015 kg/cm2 1.5 kPa) O"vo Ak 0.17 ko 0.492 56

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Surcharge / '-' / / '-' / \ \ \ \ 48.3 '-------76.2 em--------' Figure 4.4 The Finite Element Mesh for One-dimensional Compression Test 57

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19 18 ,-.... -c: 17 ------------...... ro .!:l r/J 16 15 0 ' ----------------,----------------------------------.----------------------------------' ' ' ' ' --------------... --------------------------------------------------------------------' ' ' ' ' ' ------------------------------------------------------------------------------------' ' ' ' --------------------------------------------------1----------------------------------i i 20 000 40,000 60 000 Time (min) __.,_Test GREWS Figure 4 5 The Comparison ofthe Creep Behavior of Tire Chips from GREWS Analysis and One-dimensional Compression Test 58

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4.4 Finite Element Analysis of the Glenwood Canyon Test Wall A finite element mesh was established for the Glenwood Canyon test wall as shown in Figure 4.6. The mesh includes 327 quadrilateral/triangular elements for simulation of the fill 31 beam elements for simulation of the compressed tire block face, 231 bar elements for simulation of the geogrid reinforcement and 42 interface elements for simulation of the contact surface between tire chips fill and the in-situ foundation soil. The analysis simulated the field construction sequences and time table. In this analysis, the test wall was constructed in 44 increments and it took four months to complete the construction in the field. Material parameters listed in Tables 4.3 to Table 4.7 were used as input parameters and all the input data are shown in Appendix D 59

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0'1 0 Scale 0 I l _ l r.;.... . : o l ' : ... : ... ,,\ .. :. ; ... 0 "' : : :-. .. : 0 . . : : ,:: . ... } 0 : : : l '\ ." .' .... ;.: ... : .:'. ': ,.: ... ....... ....... / 7 : ? r-T17 ___....-T Om _r--v -,.--.............. !.; / ,--,...-, v / \ I _,..... I \ / \. -v I.; / D, D quadrilater a l/ triangular element (tire chip fill) /}. D quadrilat e ra l/tria ngular element (soil fill) ----interface e lement beam (facing block) element --bar (geosynthetic reinforcement) element Figure 4.6 Finite Element Mesh for Glenwood Canyon Test Wall

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4.4.1 Comparison of Measured Results and Finite Element Analysis Results This finite element analysi s was performed based on the time dependent model and time zero means the fir s t day of construction Construction of the test wall was completed in about 4 months. The elapsed time for the analysis was 7 months, i.e., 3 months beyond the end of construction. A comparison of the wall face deformation of the analysis with the measured wall face deformation 7 months after the construction started is shown in Figure 4.7. It is seen the analysis shows slightly larger deformation than the measured value. This is considered acceptable as the predicted deformation beyond the measurement period is likely to be on the conservative side. 4.4.2 Predicted Wall Movement of Glenwood Canyon Test Wall Predicted wall movement at 75 years after construction is depicted in Figure 4.8. The maximum movement at 75 years after construction is predicted to be 2 8 m (9.1 ft) which occurs near the 7th tier. The wall movement at 7 months is also presented for comparison It is seen that since the deformation rate was decreasing with time, the movement from 7 months to 75 years is smaller than the movement in the first 7 months. It should be noted that movement is still occurring, although at a very slow rate at 75 years after construction. 61

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0\ N Scale 0 2 4 6 8 10m Design Configuration 7 months (finite element analysis) 7 months (measured) Figure 4 7 Comparison of Measured and Finite Element Analysis Result

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0\ w Scale 0 2 4 6 8 10 m Design Configuration 7 months (finite element analysis) 7 months (measured) - 75 years (finite element analysis) Figure 4.8 Predicted Wall Movement after 75 Years of Glenwood Canyon Test Wall

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5. Summary and Conclusions 5.1 Summary In October 1994, the Colorado Department of Transportation constructed a geosynthetic-reinforced retaining wall using shredded tires as backfill. The retaining wall was constructed over a landslide area along Interstate Highway-70 near Glenwood Canyon Colorado. The retainin g wall was constructed in 7 tie rs with a total height of21 m (70ft). To th e author s knowledge this was (and still is) the highest tire-shred retaining wall in the world. The wall was instrumented with survey targets and horizontal inclinometers at strategic locations to monitor its performance during and after construction. This study was undertaken to determine the engineering properties of the shredded tires (a nominal size of 5 em ( 2 in ) and to investi g ate the long-term performance the geosynthetic-reinforced retainin g wall. Long -term one-dimensional compression tests and direct shear tests were performed using a specially designed apparatus that can accommodate a specimen size of76 em by 76 em by 61 em (30 in. by 30 in. by 24 in .). The one-dimensional compression tests were performed by applyin g incremental loads to the top s urfac e of the test specimen. After a maximum pressure of 51. 7 kN / m2 (7 .5 psi) was reach e d th e load was maintained for 42 days. 64

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The direct shear tests were performed under 3 overburden pressures: 34.5 kN/m2 51. 7 kN/m2 and 69.0 kN/m2 (5 psi, 7.5 psi and 10 psi). All tests were performed at an initial unit weight of 6.3 kN/m3 ( 40 lblft\ The measured properties were then used to conduct finite element analysis using a computer model, GREW. The finite element model is capable of analyzing the time-dependent performance of the retaining wall due to its self-weight and externally applied loads. To validate the finite element model, the deformed configuration of the retaining wall as computed by the finite element model was compared with the measured deformation. After the model was properly validated, the analytical model was employed to predict the long-term performance of the retaining wall over its design life. 5.2 Findings and Conclusions The fmdings and conclusions of this study can be grouped into 3 areas : (A) laboratory tests, (B) measured performance versus finite element analysis, and (C) long-term performance of the Glenwood Canyon retaining wall. (A) Laboratory Tests The long-term one-dimensional compression tests indicated that the shredded tires experienced large time-dependent deformation. The deformation decreased with time at a decreasing rate. At the end of 65

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the test (42 days under 51.7 kN/m2 (7.5 psi) surcharge pressure), the total deformation was approximately 17.5%, and the strain rate was 0.43% per day, approximately 1140 of the strain rate in the first day of the 51.7 kN/m2 (7.5 psi) surcharge pressure. The direct shear test results indicated that the Mohr failure envelope was fairly close to being a straight line. The angle of internal friction of the tire chips was 30.5 degrees, and the cohesion was very small 0.2 kN/m2 (4.4lb/ft2). (B) Measured Performance vs Finite Element Analysis The retaining wall experienced large deformation Three months after construction, the maximum downward movement was 109 em (3.6 ft) and the maximum outward movement was 138 em (4.5 ft) measured in the 6th tier (second tier from the top) of the wall. Upon calibrations with the measured results, very good general agreement was observed between the calculated deformed configuration of the wall 3 months after construction and the measured deformation. This indicates that the finite element model is capable of analyzing time-dependent performance of the retaining wall. 66

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(C) LongTerm Performance Using the analytical model the maximum movement of the wall will be approximately 9.1 ft (2 8 m) 75 years after construction This would be excessive by any measures. The Colorado Department of Transportation attempted several remedial measures to arrest the wall movement but without an y success. The wall was subsequently demolished following a fire due to self-combustion. Future usage of shredded tires as backfill of retaining walls will require further study to fmd solutions to the following questions: (a) what are the optimum size of shredded tires for construction of retaining walls, (b) how to reduce deformation of shredded tires, (c) how to effectively compact shredded tires in the field and (d) how to avoid self-combustion of shredded tires 67

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Appendix A Survey Data : Date: 5/25/1995 TierNo. Survey Point Displacement (ft) Location 0.162 y 1 Bottom 0.210 X y 0.143 y 1 Top 0.200 X 0.191 y 2 Bottom 0.320 X L 0.221 y 2 Top 0.435 X X 0.588 y 3 Bottom 1.375 X 0.543 y 3 Top 2.000 X 1.375 y 4 Bottom 2 .655 X 1.365 y 4 Top 3.260 X 3.284 y 5 Bottom 4.150 X 2.860 y 5 Top 4.270 X 3.576 y 6 Bottom 4.440 X 3.569 y 6 Top 4.525 X 3.368 y 7 Bottom 3.980 X 3.328 y 7 Top 3.955 X 68

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Initial data for Glenwood Canyon test wall TUBE A depth A+ AINI. DIFF. 2 -279 235 -514 3 -312 270 -582 4 -331 289 -620 5 -372 332 -704 6 -409 368 -777 7 -423 383 806 8 -460 417 -877 9 -532 491 -1023 10 -581 540 -1121 11 -601 560 -1161 12 -625 584 -1209 13 -606 563 -1169 14 -570 528 -1098 15 -563 521 -1084 69

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Data for Glenwood Canyon test wall 11/27 / 94 TUBE A INI. DIFF depth A+ A-DIFF CHANGE SUM( C ) DEFF .in. step2(d) -514 2 -417 367 -784 270 2461 5.3256 -5. 3256 -582 3 -459 409 -868 286 2191 4 5873 -4. 5873 -620 4 -437 386 -823 203 1905 3 .93 -3.93 -704 5 -356 304 -660 44 1702 3.3585 -3. 3585 -777 6 -302 251 -553 224 1658 2 .8479 -2 8479 -806 7 -338 287 -625 181 1434 2.3505 -2 3505 -877 8 -418 365 -783 94 1253 1.9203 -1.9203 -1023 9 -512 457 -969 54 1159 1.5444 -1.5444 -1121 10 -537 488 -1025 96 1105 1.1967 -1.1967 -1161 II -519 466 -985 176 1009 0 .8652 -0.8652 -....l -1209 -966 833 0 5625 -0.5625 0 12 -509 457 243 -1169 13 -479 427 -906 263 590 0 3126 -0 3126 -1098 14 -474 422 -896 202 327 0.1356 -0.1356 -1084 15 -505 454 -959 125 125 0 0375 -0 0375

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Data for Glenwood Canyon test wall 12118/ 94 TUBE A INI. DIFF. depth A + A-DIFF CHANGE SUM( C ) DEFF .in. s tep3(d) -784 2 -362 301 -663 121 446 0.7407 -0.7407 -5. 3256 -6 0663 -868 3 -432 371 -803 65 325 0.6069 -0 6069 -4.5873 -5. 1942 -823 4 -438 382 -820 3 260 0 5094 -0 5094 -3.93 -4.4394 -660 5 -375 316 -691 31 257 0.4314 -0.4314 -3.3585 -3.7899 -553 6 -317 259 -576 23 226 0.3543 -0 3543 -2.8479 -3.2022 -625 7 -339 282 -621 4 203 0 2865 -0.2865 -2.3505 -2.637 -783 8 -406 347 -753 30 199 0.2256 -0.2256 -1.9203 -2.1459 -969 9 -491 436 -927 42 169 0 1659 -0 1659 -1.5444 -1.7103 -1025 10 -529 471 -1000 25 127 0.1152 -0 1152 -1.1967 -1.3119 -985 11 -507 448 -955 30 102 0 0771 -0 0771 -0 8652 -0 9423 -.....) -966 -500 442 -942 24 72 0.0465 -0 .0465 -0 5625 -0.609 ........ 12 -906 13 -471 411 -88 2 24 48 0 0249 -0 0249 -0.3126 -0.3375 -896 14 -471 412 -883 13 24 0 0105 -0 0105 -0 1356 -0 .1461 -959 15 -504 444 -948 11 11 0.0033 -0.0033 -0 0375 -0 0408

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Data for Glenwood Canyon test wall 1114/95 TUBE A depth A+ A-DIFF. INI. DIFF CHANGE SUM( C) DEF in step4(d) 2 -321 272 -593 -663 70 283 0.4092 -6 0663 -6.4755 3 -408 358 -766 -803 37 213 0.3243 -5 1942 -5.5185 4 -440 392 -832 -820 12 176 0.2604 -4.4394 -4.6998 5 -388 337 -725 -691 34 164 0.2076 -3. 7899 -3.9975 6 -320 272 -59 2 -576 16 130 0 1584 -3.2022 -3.3606 7 -355 288 -643 -621 22 114 0.1I94 -2 637 -2 7564 8 -39I 34I -732 -753 2I 92 0.0852 -2.I459 -2.23II 9 -479 427 -906 -927 21 7I 0 0576 -1.7I03 -1.7679 IO -518 470 -988 -1000 12 50 0 0363 -1.3II9 -1.3482 -..J N II -494 445 -939 -955 16 38 0 0213 -0.9423 -0.9636 I2 -488 438 -926 -942 I6 22 0.0099 -0.609 -0.6I89 I3 -469 4IO -879 -882 3 6 0 0033 -0 3375 -0.3408 I4 -468 4I6 -884 -883 1 3 O.OOIS -O.I461 -O. I476 15 -499 447 -946 -948 2 2 0.0006 -0 0408 -0 :04I4

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Data for Glenwood Canyon test wall l/25/95 TUBE A depth A + A-DIFF INI. DIFF. CHANGE SUM(C) DEF in step5(d) 2 -279 224 503 -593 90 351 0 567 -6.4755 -7. 0425 3 -380 324 -704 -766 62 261 0.4617 -5. 5185 -5. 9802 4 -444 387 -831 -832 1 199 0.3834 -4 6998 -5. 0832 5 404 349 -753 -725 28 198 0.3237 -3.9975 -4 3212 6 -323 269 -592 -592 0 170 0.2643 -3.3606 -3. 6249 7 -334 279 -613 -643 30 170 0.2133 -2. 7564 -2 9697 8 -386 327 -713 -732 19 140 0 1623 -2.2311 -2.3934 9 -468 413 -881 -906 25 121 0 1203 -1.7679 -1.8882 10 -513 457 -970 -988 18 96 0.084 -1.3482 -1.4322 ......:J \..;.) 11 -484 428 -912 -939 27 78 0 0552 -0. 9636 -1.0188 12 -481 422 -903 -926 23 51 0 0318 -0. 6189 -0 6507 13 -471 394 -865 -879 14 28 0 0165 -0. 3408 -0. 3573 14 -473 410 -883 -884 1 14 0 0081 -0. 1476 -0. 1557 15 -495 438 -933 -946 13 13 0 0039 -0. 0414 -0. 0453

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Data for Glen wood Canyon test wall 5 / 25 / 95 Tube A depth A + A DIFF. INI. DIFF CHANGE SUM(C) DEF in Step6 (d) 2 -276 271 -547 -503 44 7740 21.7305 -7. 0425 -28 773 3 -239 184 -423 -704 281 7696 19.4085 -5. 9802 2 5.3887 4 -603 569 -1172 -831 341 7415 17. 0997 -5. 0832 -22 1829 5 -759 713 -1472 -753 719 7074 14.8752 4 3212 -19 1964 6 -527 478 -1005 -592 413 6355 12. 753 -3. 6249 -16 3779 7 -350 308 -658 -613 45 5942 10. 8465 -2. 9697 -13.8162 8 -392 340 -732 -713 19 5897 9 0639 -2. 3934 -11.4573 9 -380 354 -734 -881 147 5878 7.2948 -1.888 2 -9 .183 10 -215 -111 -104 -970 866 5731 5 5314 -1.4322 -6 9636 -...] 11 -377 376 1288 4865 3.8121 -1.0188 -4 .8309 -1 -912 12 -64 -140 76 -903 979 3577 2 3526 -0. 6507 3 .003 3 13 22 -317 339 -865 1204 2598 1 2795 -0.3573 -1. 6368 14 -12 -250 238 -883 1121 1394 0 .5001 -0. 1557 -0.6558 15 -403 257 -660 -933 273 273 0 0819 -0. 0453 -0 1272

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lnitial data for Glenwood Canyon test wall TUBE B depth, ft A+ A-INI.DIFF 2 -732 687 -1419 3 -704 662 -1366 4 -662 622 -1284 5 -615 574 -1189 6 -568 525 -1093 7 -518 478 -996 8 -470 426 -896 9 -427 385 -812 10 -373 329 -702 11 -302 259 -561 12 -257 212 -469 13 -218 176 -394 14 -168 126 -294 75

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D ata f or Gle n wo od Cany on test wall 11/ 27/94 TUBE B INI.DIFF depth ft A+ ADIFF CHANGE SUM(C ) DEFF.in step 2(d ) -1419 2 -718 668 -1386 33 1600 4 .1751 -4 .1751 -1366 3 -688 643 -1331 35 1567 3 6951 -3 6951 -1284 4 -658 615 -1273 11 1532 3 225 -3 225 -1189 5 555 503 -1058 131 1521 2 7654 -2 7654 -1093 6 -480 434 -914 179 1390 2.3091 -2 .3091 -996 7 -490 442 -932 64 1211 1 .8921 -1.8921 -896 8 -517 463 -980 84 1147 1.5288 -1. 5288 -812 9 -475 429 -904 92 1063 1 1847 -1.1847 -702 10 303 255 -558 144 971 0 8658 -0 8658 ......:) -561 11 -171 117 -288 273 827 0 5745 -0 5745 0\ -469 12 -156 103 259 210 554 0 3264 -0.3264 -394 13 -146 94 -240 154 344 0 1602 -0 1602 294 14 79 25 104 190 190 0 057 -0 057

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D ata for Glen wo od Cany on test wall 12/18/94 TUBE B INI.DIFF depth ft A+ ADIFF CHANGE SUM(C ) DEFF .in. step 3(d ) -1386 2 -697 634 -1331 55 440 0 9255 -0 9255 -4 1751 -5 1006 -1331 3 -653 597 -1250 81 385 0 7935 -0 7935 -3 6951 -4.4886 -1273 4 -683 616 -1299 26 304 0 678 -0 678 -3.225 -3 903 -1058 5 -575 518 -1093 35 278 0 5868 -0.5868 -2 7654 -3.3522 -914 6 -481 423 -904 10 243 0 5034 -0 5034 -2 3091 -2 8125 -932 7 -479 422 -901 31 233 0.4305 -0.4305 -1. 8921 -2 3226 -980 8 -516 457 -973 7 202 0 3606 -0 3606 -1. 5288 -1. 8894 -904 9 -477 425 -902 2 195 0 3 -0 3 -1. 1847 1.4847 -558 10 -315 267 -582 24 193 0 2415 -0 2415 -0 8658 1 1073 -....) -288 11 -176 121 -297 9 169 0 1836 -0 1836 -0 5745 0 7581 -....) -259 12 -161 104 -265 6 160 0.1329 -0 1329 -0 3264 -0.4593 -240 13 137 78 -215 25 154 0 0849 -0 0849 -0 1602 0 2451 -104 14 55 80 25 129 129 0 0387 -0 0387 0 057 0 0957

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Data for Glenwood Canyon test wall 1/14/95 TUBE B depth A+ ADIFF INI. DIFF. CHANGE SUM DEF in. step4(d) 2 -654 609 -1263 -1331 68 364 0 7488 -5 1006 -5 8494 3 -618 567 -1185 -1250 65 296 0 6396 -4.4886 -5 1282 4 -667 617 -1284 -1299 15 231 0 5508 -3 903 -4.4538 5 -575 530 -1105 -1093 12 216 0.4815 -3 3522 -3 8337 6 -469 418 -887 -904 17 204 0.4167 -2. 8125 -3 2292 7 -469 421 -890 -901 11 187 0 3555 -2. 3226 -2 6781 8 -511 457 -968 -973 5 176 0 2994 -1. 8894 -2.1888 9 -473 423 -896 -902 6 171 0 2466 -1.4847 -1.7313 10 -307 255 -562 -582 20 165 0 1953 -1. 1073 -1.3026 -...l 11 -168 119 -287 -297 10 145 0 1458 -0 7581 -0 9039 00 12 -158 92 -250 -265 15 135 0 1023 -0.4593 -0 5616 13 -123 58 -181 -215 34 120 0 0618 -0. 2451 -0.3069 14 -75 -14 -61 25 86 86 0 0258 -0. 0957 -0 1215

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D a t a f or G le n woo d Ca n yo n t es t w all 1 / 25/95 TUBE B depth A+ ADIFF INI. DIFF CHANGE SUM DEF. i n step5(d ) 2 -616 560 -1176 -1263 87 324 0 5358 -5 8494 -6 3852 3 -590 536 1 126 -1185 59 237 0.4386 -5 1282 5 5668 4 675 618 1293 -1284 9 178 0 3675 -4.4538 -4 8213 5 597 537 -1134 1105 29 1 69 0 .3141 -3 8337 -4. 1478 6 -470 414 -884 -887 3 140 0 2634 -3 2292 -3.4926 7 -463 410 -873 -890 17 137 0 2214 -2. 6781 -2. 8995 8 503 452 -955 -968 13 120 0 1803 -2. 1888 2 3691 9 -483 425 -908 -896 12 107 0 1443 -1. 7313 1 8756 10 -309 259 -568 -562 6 95 0 1122 -1. 3026 -1.4148 -.....) 11 -167 116 -283 -287 4 89 0 0837 -0 9039 -0 9876 \0 12 -145 85 -230 -250 20 85 0 057 -0 5616 -0 6186 13 105 51 -156 -181 25 65 0 0315 -0.3069 -0 3384 1 4 -39 -18 -21 6 1 40 40 0 012 -0 1215 -0 1335

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Data for G l e nwood Canyo n t est wal l 5 / 25 / 95 Tube B depth A+ A DIFF. INI. DIFF. CHANGE SUM DEF i n step6(d) 2 -616 527 -1143 1176 33 7225 16 9035 -6 3852 -23 2887 3 -202 154 -356 -11 26 770 7192 14 736 -5 5668 -20 3028 4 -910 855 1765 -1293 472 6422 12. 5784 -4 8213 17 3997 5 -922 868 1790 -1134 656 5950 10 6518 -4 1478 -14 7996 6 -410 360 -770 -884 114 5294 8 8668 -3.4926 -12 3594 7 -205 153 -358 -873 515 5180 7 2786 -2 8995 -10 1781 8 -503 446 -949 -955 6 4665 5 7246 2 3691 -8 0937 9 -366 289 -655 908 253 4659 4 3251 -1. 8756 6 2007 10 339 -420 759 -568 1327 4406 2 9274 -1.4148 -4 3422 00 0 11 601 -668 1269 -283 1552 3079 1 6056 -0 9876 -2 5932 12 298 -422 720 -230 950 1527 0 6819 -0 6186 -1. 3005 13 102 -150 252 -156 408 577 0 2238 -0.3384 -0 5622 14 49 -99 148 -21 169 169 0 0507 -0 1335 -0 1842

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Appendix B One-dimensional Compression Test Date Stress Stress Stress Time Elap. T DISP DISP Strain Strain/T Disp / T DISP/T /1995 Airbag Cale'd Pa min min in em /min in/min em/min 2/16 0 0.063 434.4 0 0 0 0 0 0 2/17 2.00 1.772 12217.9 1440 1.4592 3.7064 0.0768 10.1333 25.7387 2 /18 4 00 3.481 24001.5 2880 2 3636 6.0035 0.1244 8 2069 20 8456 2 /19 6.00 5 189 35778 2 4320 3 0191 7.6685 0.1589 6.9887 17.7512 2 / 20 6.70 5 787 39902 5 4500 3 1160 7.9146 0.1640 6 9244 17. 5881 2 / 20 7.10 6 129 42258.6 4680 3.1863 8.0932 0.1677 6 8083 17.2932 2 / 20 7 30 6.300 43436 7 4860 3 2148 8.1656 0.1692 6.6148 16.8016 2 / 20 7.40 6.385 44025.7 5040 3.2319 8 2090 0 .1701 6.4125 16. 2878 00 2 / 20 7.43 6.411 44202.4 5220 3 2395 8 2283 0 1705 6.2059 15.7631 -2 / 20 7.47 6.445 44438.0 5400 3.2471 8.2476 0 1709 6.0131 15. 2734 2 / 20 7.49 6.462 44555.8 5580 3 2547 8 2669 0 1713 5 8328 14 8153 2 / 20 7 50 6.471 44617 5 5760 0 3 2604 8 2814 0 1716 0 5 6604 14. 3775 2 /21 7 50 6.471 44617.5 7200 1440 3.2655 8 2944 0 1719 11.9353 4.5354 11. 5200 2 / 22 7.50 6.471 44617 5 8640 2880 3 2706 8 3073 0 .1721 5 9770 3 7854 9.6150 2 /23 7 50 6.471 44617 5 10080 4320 3 2750 8 3185 0 1724 3.9900 3.2490 8.2525 2 / 24 7.50 6.471 44617 5 11520 5760 3 2804 8.3322 0 1727 2.9974 2.8476 7.2328 2 / 25 7.50 6.471 44617.5 12960 7200 3.2849 8.3436 0.1729 2.4012 2 5346 6.4380 2 / 26 7.50 6.471 44617 5 14400 8640 3 2891 8.3543 0 .1731 2 0036 2 2841 5.8016

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Date Stress Stress Stress Time Elap. T DISP DISP Str ain Strain!T Disp / T DIS PIT / 1995 Airbag Cale'd Pa min min in em / min in/min em/min 2 / 27 7.50 6.471 44617 5 15840 10080 3.2923 8.3624 0.1733 1.7190 2.0785 5 2793 2 / 28 7 50 6.471 44617 5 17280 11520 3 2954 8 3703 0 1734 1 5056 1 9071 4.8439 311 7 50 6.471 44617 5 18720 12960 3.2983 8 3777 0 1736 1 3395 1.7619 4.4753 3 / 2 7 50 6.471 44617 5 20160 14400 3 3002 8 3825 0.1737 1.2062 1 6370 4 1580 3 / 3 7.50 6.471 44617.5 21600 15840 3.3024 8 3881 0.1738 1 0973 1.5289 3 8834 3 / 4 7 50 6.471 44617 5 23040 17280 3 3049 8 3944 0 1739 1 0066 1.4344 3 6434 3 / 5 7 50 6.471 44617 5 24480 18720 3 3065 8 3985 0 1740 0.9296 1.3507 3.4308 3 / 6 7.50 6.471 44617 5 25920 20160 3.3078 8.4018 0 .1741 0.8636 1.2762 3 2414 317 7 50 6.471 44617 5 27360 21600 3.3090 8.4049 0.1742 0.8063 1 2094 3 0720 3 / 8 7.50 6.471 44617 5 28800 23040 3 3104 8.4084 0 1742 0.7562 1.1494 2 9196 3/9 7 50 6.471 44617.5 30240 24480 3 3116 8.4115 0 1743 0.7120 1.0951 2.7816 00 3/10 7.50 44617.5 N 6.471 31680 25920 3 3127 8.4143 0.1744 0.6727 1.0457 2 6560 3 /11 7.50 6.471 44617.5 33120 27360 3 3137 8.4168 0 1744 0.6374 1 0005 2.5413 3112 7.50 6.471 44617 5 34560 28800 3 3146 8.4191 0.1745 0.6057 0 9591 2.4361 3113 7.50 6.471 44617 5 36000 30240 3.3155 8.4214 0 1745 0.5771 0 9210 2 3393 3114 7.50 6.471 44617.5 37440 31680 3 3163 8.4234 0.1745 0.5510 0.8858 2 2498 3115 7 50 6.471 44617.5 38880 33120 3.3170 8.4252 0 1746 0.5271 0.8531 2.1670 3116 7 50 6.471 44617.5 40320 34560 3.3177 8.4270 0.1746 0.5053 0 8228 2 0900 3 /17 7 50 6.471 44617 5 41760 36000 3.3184 8.4287 0 1747 0.4851 0.7946 2.0184 3 /18 7.50 6.471 44617 5 43200 37440 3.3189 8.4300 0 1747 0.4666 0.7683 1.9514 3 /19 7.50 6.471 44617.5 44640 38880 3.3194 8.4313 0.1747 0.4493 0 7436 1.8887

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Date Stress Stress Stress Time Elap T DISP DISP Strain Strain!T Disp / T DISP / T / 1995 Airbag Cale'd Pa min min in em / min in/min em/min 3 /19 7.50 6.471 44617.5 44640 38880 3 3194 8.4313 0.1747 0.4493 0.7436 1 8887 3 / 20 7.50 6.471 44617 5 46080 40320 3 3199 8.4325 0 1747 0.4334 0.7205 1.8300 3 /21 7.50 6.471 44617 5 47520 41760 3 3206 8.4343 0 1748 0.4185 0 6988 1.7749 3 / 22 7 50 6.471 44617 5 48960 43200 3 3210 8.4353 0 1748 0.4046 0 6783 1 7229 3 / 23 7.50 6.471 44617 5 50400 44640 3 3213 8.4361 0 1748 0 3916 0 6590 1 6738 3 / 24 7.50 6.471 44617 5 51840 46080 3.3216 8.4369 0 1748 0.3794 0 6407 1.6275 3 / 25 7.50 6.471 44617.5 53280 47520 3 3219 8.4376 0 1748 0.3679 0 6235 1 5836 3 / 26 7 50 6.471 44617.5 54720 48960 3.3222 8.4384 0 1749 0 3571 0.6071 1.5421 3 / 27 7 50 6.471 44617 5 56160 50400 3.3227 8.4397 0 1749 0.3470 0 5916 1 5028 3 / 28 7.50 6.471 44617 5 57600 51840 3.3233 8.4412 0 1749 0.3374 0.5770 1.4655 3 / 29 7.50 6.471 44617 5 59040 53280 3.3235 8.4418 0 1749 0.3283 0 5629 1.4298 00 3 / 30 7.50 6.471 44617 5 60480 54720 3.3238 8.4424 0.1749 0.3197 0 5496 1.3959 w 3 /31 7 50 6.471 44617 5 61920 56160 3.3240 8.4430 0 1749 0.3115 0 5368 1.3635 4 / 1 7.50 6.471 44617 5 63360 57600 3 3243 8.4436 0 1750 0.3038 0 5247 1 3326 4 / 2 7.50 6.471 44617 5 64800 59040 3.3245 8.4442 0 1 7 50 0.2964 0 5130 1.3031

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Date GREWS GREWS GREWS / 1995 in em Reading 2 /16 0 0 48 2600 2/17 3 .8483 9 7747 38.48535 2 /18 3 7838 9 6110 38.64905 2119 3 7621 9 5558 38 7042 2 / 20 3 7607 9 5522 38.70785 2 / 20 3.7591 9 5482 38 7118 2 / 20 3 7575 9.5441 38.71585 2/ 20 3 7560 9 5402 38 71985 2/20 3 7544 9.5362 38 72385 2 / 20 3 7529 9.5324 38.7276 2 / 20 3 7515 9 5288 38 73125 2 / 20 3.7501 9.5253 38 7347 2 /21 3.7401 9.4999 38 7601 2 / 22 3 7331 9.4820 38 778 2 /23 3 7279 9.4689 38 7911 2 / 24 3 7241 9.4592 38.8008 2 /25 3 7212 9.4518 38 .8082 2 / 26 3 7190 9.4463 38 81375 2 / 27 3 7173 9 4420 38 81805 2 / 28 3.7161 9.4388 38 .8212 3 / 1 3.7151 9.4364 38 82365 3 / 2 3 7144 9.4346 38 .8254 3 / 3 3 7139 9.4334 38 .82665 3 / 4 3 7136 9.4326 38 .82745 3 / 5 3.7134 9.4322 38 .82785 3/ 6 3.7134 9.4321 38 .82795 3/7 3.7134 9.4322 38.82785 3 / 8 3 7136 9.4326 38.8274 3 / 9 3 7139 9.4332 38 .8268 3/10 3 7142 9.4341 38 .8259 84

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Date GREWS GREWS GREWS / 1995 in em Reading 3/11 3.7147 9.4353 38 8247 3/12 3.7153 9.4369 38.82315 3/13 3 7162 9.4391 38 82095 3 /14 3 7176 9 4428 38 81725 3/15 3.7208 9.4509 38 8091 3/16 3 7255 9.4629 38 79715 3/17 3 7271 9.4668 38 79325 3 /18 3.7325 9.4805 38 77955 3 /19 3.7383 9.4954 38 7646 3 / 20 3.7499 9 5248 38 7352 3 /21 3 7528 9.5321 38.7279 3 / 22 3 7602 9.5510 38 70905 3 / 23 3 7709 9.5782 38.68185 3 / 24 3 7722 9.5813 38 6787 3 / 25 3 7831 9 6091 38 65095 3 / 26 3 7908 9 6286 38.63145 3 / 27 3 7918 9 6310 38 62895 3/28 3.8010 9 6546 38 60545 3 / 29 3.8068 9.669 3 38 5907 3 / 30 3.8083 9.6730 38 587 3 /31 3 8183 9.6985 38 5615 4/1 3 8254 9 7165 38.5435 4 / 2 3 8262 9 7186 38 54145 85

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Direct Shear Test (Shear box 30"x30") Project No. : 92005 CDOT Project name: Glenwood Canyon Material 2" shredded tires Data : 9 /1911994 Sample No Nonnal Stres s Shear Stress (Shear@ 20%) kPa kPa SHR25 37.2 21.1 SHR275 55. 5 34.9 SHR210 73.8 42 7 86

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Appendix C Input data ofFinite Element Analysis for 1-D Compression Test em min kg One-Dimensional Compression 3/28/96 1 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 001 O o O EO 1 0 0 032 0 0 5 1. 223 0 0 1 6690000 6690000 0 00155 0 0 492 Oo0155 0 0 4 9 0 0055 Oo00012 O o149 Oo93 OoO 1 1 1 1 1 1 1 10 0 0 1 1 0 0 0 0 2 43o0 0 0 3 0 0 9o652 4 43 0 0 9 o 652 5 0 0 190304 6 4300 190304 7 0 0 280956 8 43 o 0 28o956 9 0 0 380608 10 43 0 0 38 o 608 E 11 0 0 48026 12 4300 48 o26 1 1 2 4 3 1 2 3 4 6 5 1 3 5 6 8 7 1 4 7 8 10 9 1 E 5 9 10 12 11 1 1 2 1 1 E 3 12 1 1 0 1 1 0 2 1 0 4 2 0 2 2 0 4 3 0 2 3 0 4 4 0 2 4 0 4 5 0 2 5 0 3 E 5 0 4 E 1 11 12 -00125 2 0 0 0 0 0 1 1430o 0 1 3 0 0 0 0 1 1 1000 1 E 1 11 12 0 012 4 0 0 0 0 0 1 14300 0 1 87

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E E E E E E E E E 5 0 0 1 11 1 2 6 0 0 7 0 0 1 11 12 8 0 0 9 0 0 1 11 1 2 10 0 0 11 0 0 1 11 12 12 0 0 13 0 0 1 11 12 14 0 0 15 0 0 1 11 12 16 0 0 17 0 0 1 11 12 18 0 0 19 0 0 1 11 12 20 0 0 21 0 0 1 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 12 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 -0.12 0 0 0 1 -0.042 0 0 0 1 -0.024 0 0 0 1 -0.012 0 0 0 1 -0.006 0 0 0 1 -0.0018 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 -0.0024 0 0 1 0 1 1 -0.0012 0 0 1 0 1 1 -0.0006 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 88 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 10.0 1430.0 10.0 170.0 10.0 170.0 10. 0 170.0 10.0 170.0 10. 0 170.0 10. 0 170.0 10. 0 170.0 10.0 170.0 1440. 0 1440.0 1440. 0 1440. 0 1440.0 1440. 0 1440.0 1440. 0 1440.0 1440. 0 1440. 0 1440.0 1440.0 1440.0 1440. 0 1440.0 1440.0 1440.0 1440.0 1440.0 1440.0 1440. 0 1440.0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

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46 0 0 0 0 0 1 1440 0 1 47 0 0 0 0 0 1 1440.0 1 48 0 0 0 0 0 1 1440.0 1 49 0 0 0 0 0 1 1440. 0 1 50 0 0 0 0 0 1 1440. 0 1 51 0 0 0 0 0 1 1440. 0 1 52 0 0 0 0 0 1 1440.0 1 53 0 0 0 0 0 1 1440. 0 1 54 0 0 0 0 0 1 1440. 0 1 55 0 0 0 0 0 1 1440. 0 1 56 0 0 0 0 0 1 1440.0 1 57 0 0 0 0 0 1 1440.0 1 58 0 0 0 0 0 1 1440.0 1 59 0 0 0 0 0 1 1440 0 1 60 0 0 0 0 0 1 1440.0 1 61 0 0 0 0 0 1 1440.0 1 62 0 0 0 0 0 1 1440.0 1 E 63 0 0 0 0 0 1 1440.0 1 89

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Appendix D Input Finite Element Analysis data for Glenwood Canyon Test Wall ern kg day Glenwood Canyon Test Wall! 3/26/96 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0.001 0.0 0 1 0 .032 0 5 1. 223 0 1 963360000.963360000. 0 .151 0 4 92 0 .151 0. 4 9 0.005 0.2 0 .149 0 .93 0 0 1 2 80.67 25.47 0 .244 0 .357 864000. 864000. 1.0 0 0 2 3 281.23 116.1 20229. 3 4 1. 406 1. 61 E4 5 0 .003822 1000000.0 0 .303 0 .653 0.0 0.371 1 1 1 1 1 1 1 0 .0001 2 1 0 0 2 0. 0 3 60.96 0. 4 60.96 0 5 121. 92 0. 6 121. 92 0 7 182.88 0 8 182.88 0. 9 0 30.48 12 182.88 30. 48 1 3 2 1 3 .36 30.48 14 213.36 30.48 15 0. 91.44 18 182.88 91 44 19 259.08 91.44 20 259.08 91.44 2 1 0 152. 4 24 182.88 152.4 25 264.57 152. 4 26 320. 04 152. 4 27 320. 04 152. 4 28 0 213.36 31 182.88 213.36 32 268.83 213. 36 33 327.66 213.36 34 365.76 213.36 35 365.76 213.36 36 0 274.32 39 182.88 274.32 40 274.32 274.32 41 335.28 274.32 90

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42 365.76 274.32 43 426.72 274.32 44 426.72 274.32 45 0 304 8 46 60 .96 304. 8 47 121.92 312.42 48 182.88 320. 04 49 274.32 335.28 50 335.28 335.28 51 365.76 335.28 52 426.72 335.28 53 472. 44 335.28 54 472.44 335.28 55 274.32 396. 24 56 335.28 396. 24 57 365.76 396. 24 58 426.72 396. 2 4 59 4 68 4 8 396. 2 4 60 533. 4 396. 24 61 533. 4 396. 24 62 274.32 457. 2 63 335.28 457.2 64 365.76 457. 2 65 426.72 457. 2 66 463.3 457.2 67 527. 3 457.2 68 579.12 457.2 69 579.12 457.2 70 274.32 518.16 71 335.28 518.16 72 365.76 518.16 73 426.72 518.16 74 459.03 518.16 75 521.21 518.16 76 576. 4 518.16 77 640.08 518.16 78 640.08 518.16 79 274.32 548. 64 80 335. 28 548. 64 81 365.76 548.64 82 426.72 548.64 83 457. 2 548. 64 84 518.16 548.64 85 575. 5 548.64 86 637. 0 548. 64 87 670.56 548. 64 88 670.56 548.64 89 274.32 579.12 90 335.28 579.12 91 365.76 586. 74 91

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92 426.72 601. 98 93 457.2 609.6 94 518.16 609.6 95 573.33 609. 6 96 62 9. 72 609. 6 97 670.56 609.6 98 746.76 609. 6 99 746.76 609. 6 100 457. 2 670.56 101 518.16 670.56 102 569. 98 670.56 103 623.62 670.56 1 04 670.56 670.56 105 746.76 670.56 106 807.72 670.56 107 807.72 670.56 108 457.2 731.52 109 518.16 731.52 110 568.15 731.52 111 617.22 731.52 112 670.56 731.52 113 746.76 731.52 114 807. 72 731.52 115 883. 92 7 31.52 116 883.92 731.52 117 457. 2 792.48 118 518.16 792.48 119 565. 71 792.48 120 609. 6 792.48 121 670.56 792.48 122 746.76 792.48 123 807. 72 792.48 124 883. 92 792.48 125 944.88 792.48 126 944.88 792.48 127 457. 2 853.44 128 518.16 853.44 129 563.88 861.06 130 609.6 868.68 131 670.56 868.68 132 746.76 868.68 133 807.72 868. 68 134 883. 92 868.68 135 944 .88 868.68 136 1036.32 868.68 137 1036.32 868.68 138 609. 6 929. 64 139 670.56 929. 64 140 746.76 929. 64 141 807.72 929.64 92

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142 883.92 929. 64 143 944.88 929.64 144 1036.32 929. 64 145 1097.28 929. 64 146 1097.28 929. 64 147 609.6 990. 6 148 670.56 990. 6 149 746.76 990. 6 150 807.72 990. 6 151 883.92 990.6 152 944.88 990.6 153 1036.32 990.6 154 1097.28 990. 6 155 1173.48 990. 6 156 1173.48 990. 6 157 609.6 1051.56 158 670.56 1051.56 159 746.76 1051.56 160 807.72 1051.56 161 883. 92 1051.56 162 944.88 1051.56 163 1036.32 1051.56 164 1097.28 1051.56 165 1169.2 1051.56 166 1234. 44 1051.56 167 1234. 44 1051.56 168 609.6 1112.52 169 670.56 1112.52 170 746.76 1112. 52 171 807.72 1112.52 172 883. 92 1112 .52 173 944.88 1112.52 174 1036.32 1112 .52 175 1097.28 1112.52 176 1166.2 1112.52 177 1232.3 1112.52 178 1310. 64 1112.52 179 1310. 64 1112.52 180 746.76 1143. 0 181 807.72 1173. 48 182 883.92 1173.48 183 944.88 1173.48 184 1036.32 1173.48 185 1097.28 1173.48 186 1161.9 1173.48 187 1230.5 1173.48 188 1305. 2 1173.48 189 1371. 6 1173.48 190 1371. 6 1173. 48 191 883. 92 1203.96 93

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192 944.88 1234.44 193 1036.32 1234.44 194 1097.28 1234.44 195 1158.24 1234.44 196 1228. 2 1234.44 197 1301.0 1234.44 198 1366. 0 1234. 44 199 1447.8 1234.44 200 1447. 8 1234.44 201 1036.32 1264. 92 202 1097.28 1295.4 203 1158.24 1295.4 204 1227.0 1295.4 205 1297. 0 1295.4 206 1361. 0 1295. 4 207 1443. 0 1295. 4 208 1508.76 1295. 4 209 1508.76 1295. 4 210 1097.28 1356. 36 211 1158.24 1356. 36 212 1225.0 1356.36 213 1292. 0 1356.36 214 1356.0 1356.36 215 1438.0 1356.36 216 1503. 0 1356.36 217 1584.96 1356.36 218 1584.96 1356.36 2 1 9 1097.28 1417.32 220 1158.24 1417.32 221 1223.0 1417.32 222 1287.0 1417.32 223 1351.0 1417.32 224 1433. 0 1417.32 225 1498.0 1417.32 226 1576. 0 1417.32 227 1645.92 1417.32 228 1645.92 1417.32 229 1097.28 1508.76 230 1158.24 1508.76 231 1220.7 1508.76 232 1280.16 1508.76 233 1341.12 1508.76 234 1427.0 1508.76 235 1492.0 1508.76 236 1570.0 1508.76 237 1645.92 1508.76 238 1 752. 6 1508.76 239 1752. 6 1508.76 240 1097.28 1539. 24 241 1158.24 1539. 24 94

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242 12190 2 1554048 243 1280016 1569072 244 1341012 1569 0 72 245 142200 1569 0 72 246 14870 0 1569 0 72 247 156500 1569072 248 1645o92 1569072 249 17520 6 1569 0 72 250 18280 8 1569072 251 18280 8 1569072 252 1280016 1630068 253 1341012 1630068 254 14170 0 1630068 255 14820 0 163006 8 256 15600 0 1630068 257 1645092 1630o68 258 175206 1630o68 259 18280 8 1630068 260 1889076 1630068 261 1889076 1630068 262 1280o16 16910 64 263 1341.12 1691064 264 1413o0 1691.64 265 14780 0 1691.64 266 155600 16910 64 267 1645o92 1691.64 268 175206 1691.64 269 1828o8 1691. 64 270 1889076 1691.64 271 1950o72 1691. 64 272 1950072 1691. 64 273 1280016 1783008 274 1341.12 1783o08 275 1405o0 1783o08 276 1463o04 1783008 277 15240 0 1783008 278 1645o92 1783008 279 17520 6 1783008 280 182808 1783 0 08 281 1889076 1783 0 08 282 1950072 1783o08 283 20570 4 1783o08 284 20570 4 1783 0 08 285 1280o16 1813056 286 1341. 12 1813056 287 1402008 182808 288 1463o04 1844004 289 15240 0 1844004 290 1645092 1844004 291 17520 6 1844004 95

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292 1828. 8 1844.04 293 1889.76 1 844.04 294 1950.72 1844.04 295 2057. 4 1844. 04 296 2133. 6 1844. 04 297 2133. 6 1844. 04 298 1463.04 1905. 0 299 1524. 0 1905. 0 300 1645.92 1905. 0 301 1752. 6 1905. 0 302 1828.8 1905. 0 303 1889.76 1905. 0 304 1950.72 1905.0 305 2057.4 1905. 0 306 2133.6 1905. 0 307 2194.56 1905. 0 308 2194.56 1905. 0 309 1463. 04 1965.96 310 1524.0 1965.96 311 1645. 92 1965.96 312 1752. 6 1965.96 313 1828.8 1965.96 314 1889.76 1965.96 315 1950.72 1965.96 316 2057.4 1965.96 317 2133. 6 1965.96 318 2194.56 1965.96 319 2270.76 1965.96 320 2270.76 1965.96 321 1463.04 2026. 92 322 1524. 0 2026. 92 323 1645. 92 2026. 92 324 1752. 6 2026.92 325 1828. 8 2026. 92 326 1889.76 2026.92 327 1950.72 2026. 92 328 2057. 4 2026.92 329 2133. 6 2026.92 330 2194.56 2026. 92 331 2270.76 2026.92 332 2331.72 2026. 92 333 2331. 72 2026.92 334 1463. 04 2087.88 335 1524. 0 2087.88 336 1645.92 2087.88 337 1752. 6 2087.88 338 1828.8 2087.88 339 1889.76 2087.88 340 1950.72 2087.88 341 2057.4 2087.88 96

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342 2133.6 2087.88 343 2194.56 2087.88 344 2270.76 2087.88 345 2331.72 2087.88 346 2407. 92 2087.88 347 2407.92 2087.88 348 1645.92 2133.6 349 1752. 6 2148.84 350 1828. 8 2148.84 351 1889.76 2148.84 352 1950.72 2148. 84 353 2057.4 2148.84 354 2133.6 2148.84 355 2194.56 2148.84 356 2270.76 2148.84 357 2331.72 2148.84 358 2407.92 2148. 84 359 2468.88 2148. 84 360 2468.88 2148. 84 361 1828.8 2179.32 362 1889.76 2194.56 363 1950.72 2209.8 364 2057.4 2209.8 365 2133.6 2209. 8 366 2194.56 2209.8 367 2270.76 2209.8 368 2331.72 2209. 8 369 2407.92 2209.8 370 2468.88 2209.8 371 2545.08 2209.8 372 2545. 08 2209.8 373 2057.4 2249.42 374 2133. 6 2270.76 375 2194.56 2286.0 376 2270.76 2286. 0 377 2331.72 2286.0 378 2407.92 2286. 0 379 2468.88 2286.0 380 2545. 08 2286.0 381 2590.8 2286.0 382 2590.8 2286.0 383 2270.76 2316. 48 384 2331.72 2331.72 385 2407.92 2346.96 386 2468.88 2346.96 387 2545.08 2346.96 388 2621.28 2346.96 389 2621.28 2346.96 390 2468.88 2377.44 391 2545.08 2392. 68 9 7

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392 2621.28 2423.16 393 2682.24 2438.4 E 394 2682. 24 2438.4 1 1 9 3 2 1 3 10 9 2 3 2 4 3 1 5 4 3 5 11 10 2 5 4 6 5 3 5 6 5 7 1 2 11 2 7 6 8 7 5 5 8 7 13 12 2 9 8 14 13 7 5 E 10 9 10 4 13 1 0 1 0 0 0 2 0 1 1 1 0.0 0.0 0.0 0 4 0 1 1 1 0.0 0.0 0 0 0 6 0 1 1 1 0.0 0.0 0.0 0 8 0 1 1 1 0.0 0.0 0 0 0 9 0 1 0.0 0 E 14 0 1 1 1 0 0 0.0 0.0 0 2 0 1 2 0 4 4 0 1 6 0 1 E 8 0 2 0 2 0 0 -0.0016 0.0 0 4 0 0 -0.0016 0.0 0 6 0.0 -0.0016 0 0 E 0 8 0.0 -0.0016 0.0 2 0 1 1 1 1 1 4 0 2 14 9 15 3 15 9 10 16 15 2 16 10 11 17 16 2 18 19 14 20 19 13 5 E 20 15 1 6 4 23 15 0 1 0 0 0 E 20 0 1 1 1 0.0 0.0 0.0 0 15 0 4 E 18 0 2 E 0 15 18 0 0 -0.0016 0 0 3 0 1 1 1 1 1 4 0 2 24 15 21 3 25 15 16 22 2 1 2 26 16 17 23 2 2 2 28 29 19 26 25 2 30 20 27 26 19 5 E 31 21 22 4 35 21 0 1 0 0 0 E 27 0 1 1 1 0 0 0 0 0 0 0 25 0 4 98

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E 29 0 2 E 0 25 29 0 0 -0.0016 0.0 4 0 1 1 1 1 1 4 0 2 36 21 28 3 37 21 22 29 28 2 38 22 23 30 29 2 41 42 26 34 33 2 43 27 35 34 26 5 E 44 28 29 4 49 28 0 1 0 0 0 E 35 0 1 1 1 0.0 0 0 0 0 0 37 0 4 E 42 0 2 E 0 37 42 0 0 -0.0016 0 0 5 0 1 1 1 1 1 4.0 2 50 28 36 3 51 28 29 37 36 2 52 29 30 38 37 2 56 57 34 43 4 2 2 58 35 44 43 34 5 E 59 40 41 4 61 36 0 1 0 0 0 E 44 0 1 1 1 0.0 0.0 0.0 0 51 0 4 E 57 0 2 E 0 51 57 0.0 -0.0016 0 0 6 0 1 1 1 1 1 4.0 2 62 36 45 3 63 36 37 46 45 2 64 37 38 47 46 2 66 67 40 49 3 68 40 41 50 49 2 70 71 43 53 52 2 72 44 54 53 43 5 E 73 49 50 4 76 40 0 1 0 0 0 45 0 1 0 0 0 49 0 1 0 0 0 E 54 0 1 1 1 0 0 0 0 0.0 0 63 0 3 63 0 4 64 0 3 65 0 3 66 0 3 E 71 0 2 0 63 66 0 0 0 .0016 0.0 E 0 68 71 0.0 -0.0016 0.0 7 0 1 1 1 1 1 4.0 2 77 49 55 3 78 49 50 56 55 2 99

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79 50 51 57 56 2 81 82 53 60 59 2 83 54 61 60 53 5 E 84 55 56 4 88 55 0 1 0 0 0 E 61 0 1 1 1 0 0 0 0 0 0 0 78 0 4 E 82 0 2 E 0 78 82 0 0 -0.0016 0 0 8 0 1 1 1 1 1 4 0 2 89 55 62 3 90 55 56 63 62 2 91 56 57 64 63 2 94 95 60 68 67 2 96 61 69 68 60 5 E 97 62 63 4 102 62 0 1 0.0 0 E 69 0 1 1 1 0.0 0.0 0.0 0 90 0 4 E 95 0 2 E 0 90 95 0 0 0 .0016 0 0 9 0 1 1 1 1 1 4 0 2 103 62 70 3 104 62 63 n 70 2 105 63 64 72 71 2 109 110 68 77 76 2 111 69 7 8 77 68 5 E 112 7 0 71 4 118 70 0 1 0 0 0 E 78 0 1 1 1 0.0 0 0 0 0 0 104 0 4 E 110 0 2 E 0 104 110 0 0 -0.0016 0 0 10 0 1 1 1 1 1 4 0 2 119 70 79 3 120 70 71 80 79 2 121 71 72 81 80 2 126 127 77 87 86 2 128 78 88 87 77 5 E 129 83 84 4 132 79 0 1 0 0 0 E 88 0 1 1 1 0.0 0.0 0 0 0 120 0 4 E 127 0 2 E 0 120 127 0 0 0 0 016 0 0 11 0 1 1 1 1 1 4.0 2 133 7 9 89 3 134 79 80 90 89 2 135 80 8 1 9 1 90 2 137 138 83 93 3 100

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r... _l_'I::J :?.J :?'I 'I _!_'!:? 83 0 1 0.0 0 89 0 1 0.0 0 93 0 1 0.0 0 E 99 0 1 1 1 0 0 0.0 0 0 0 134 0 3 134 0 4 135 0 3 136 0 3 137 0 3 E 143 0 2 0 134 137 0 0 0 .0016 0 0 E 0 139 143 0 0 0 .00064 0 0 1 2 0 1 1 1 1 1 4.0 2 150 93 100 3 151 93 94 101 100 1 152 94 95 102 101 1 155 156 98 106 105 1 157 99 107 106 98 5 E 158 100 101 4 163 100 0 1 0 0 0 E 107 0 1 1 1 0.0 0.0 0 0 0 151 0 4 E 156 0 2 E 0 151 156 0 0 -0.00064 0.0 1 3 0 1 1 1 1 1 4.0 2 164 100 108 3 165 100 101 109 108 1 166 101 102 llO 109 1 170 171 106 ll5 114 1 172 107 ll6 ll5 106 5 E 173 108 109 4 179 108 0 1 0 0 0 E ll6 0 1 1 1 0 0 0 0 0 0 0 165 0 4 E 171 0 2 E 0 165 171 0.0 -0.00064 0 0 14 0 1 1 1 1 1 4 0 2 180 108 ll7 3 181 108 109 ll8 117 1 182 109 110 ll9 ll8 1 187 188 ll5 125 1 24 1 189 116 126 125 ll5 5

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E 188 0 2 E 0 181 188 0 0 -0.00064 0.0 15 0 1 1 1 1 1 4 0 2 198 117 127 3 199 117 118 128 127 1 200 118 119 129 128 1 201 202 120 130 3 203 120 121 131 130 1 204 121 122 132 131 1 207 208 125 136 135 1 209 126 137 136 125 5 E 210 130 131 4 215 120 0 1 0 0 0 127 0 1 0 0 0 130 0 1 0.0 0 E 137 0 1 1 1 0 0 0 0 0.0 0 199 0 3 199 0 4 200 0 3 201 0 3 E 208 0 2 0 199 201 0 0 -0.00064 0 0 E 0 203 208 0 0 -0.00064 0 0 16 0 0 0 0 1 1 1.0 2 1 127 0 0 -3. 8 0 0 1 128 129 0 0 -7. 5 0 0 E 1 130 0 0 -3. 8 0 0 17 0 1 1 1 1 1 4.0 2 216 130 138 3 217 130 131 139 138 1 218 131 132 140 139 1 222 223 136 145 144 1 224 137 146 145 136 5 E 225 138 139 4 231 138 0 1 0.0 0 E 14 6 0 1 1 1 0.0 0 0 0 0 0 217 0 4 E 223 0 2 E 0 217 223 0.0 -0.00064 0.0 18 0 1 1 1 1 1 4.0 2 232 138 147 3 233 138 139 1 48 147 1 234 139 140 14 9 148 1 239 240 145 155 154 1 2 4 1 146 156 155 1 45 5 E 242 147 148 4 249 147 0 1 0 0 0 E 156 0 1 1 1 0 0 0 0 0 0 0 233 0 4 E 240 0 2 102

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E 0 233 240 0.0 -0.00064 0.0 19 0 1 1 1 1 1 4.0 2 250 147 157 3 251 147 148 158 157 1 252 148 149 159 158 1 258 259 155 166 165 1 260 156 167 166 155 5 E 261 157 158 4 269 157 0 1 0.0 0 E 167 0 1 1 1 0 0 0.0 0.0 0 251 0 4 E 259 0 2 E 0 251 259 0 0 -0.00064 0 0 20 0 1 1 1 1 1 4 0 2 270 157 168 3 271 157 158 169 168 1 272 158 159 1 7 0 169 1 279 280 166 178 177 1 281 167 179 178 166 5 E 282 168 169 4 290 168 0 1 0.0 0 E 17 9 0 1 1 1 0.0 0.0 0.0 0 271 0 3 271 0 4 E 280 0 2 E 0 271 280 0 0 -0.00064 0 0 21 0 1 1 1 1 1 1.0 2 291 169 170 180 1 292 170 171 181 180 1 293 171 172 182 181 1 299 300 178 189 188 1 E 301 179 190 18 9 178 5 E 190 0 1 1 1 0 0 0.0 0.0 0 291 0 3 292 0 3 E 300 0 2 E 0 291 300 0.0 -0.00064 0.0 22 0 1 1 1 1 1 1.0 2 302 181 182 191 1 303 182 183 192 191 1 304 183 184 193 192 1 309 310 189 199 198 1 311 190 200 199 189 5 E 312 194 195 4 316 E 200 0 1 1 1 0 0 0.0 0.0 0 302 0 3 303 0 3 E 310 0 2 E 0 302 310 0 0 -0.00064 0.0 23 0 1 1 1 1 1 4.0 2 103

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317 192 193 201 1 318 193 194 202 201 1 319 194 202 3 320 194 195 203 202 1 321 195 196 204 203 1 324 325 199 208 207 1 326 200 209 208 199 5 E 327 202 203 4 332 194 0 1 0 0 0 202 0 1 0 0 0 E 209 0 1 1 1 0.0 0.0 0.0 0 317 0 3 318 0 3 E 325 0 2 0 317 318 0.0 0 .00064 0 0 E 0 320 325 0 0 -0.00064 0.0 24 0 0 0 0 1 1 1.0 2 1 168 0.0 -3.8 0 0 1 169 0 0 -7. 5 0 0 1 180 181 0 0 -7.5 0.0 1 191 192 0 0 -7. 5 0 0 1 201 0 0 -7. 5 0 0 E 1 202 0.0 -3.8 0 0 25 0 1 1 1 1 1 4 0 2 333 202 210 3 334 202 203 211 210 1 335 203 204 2 1 2 211 1 339 340 208 217 2 1 6 1 341 209 2 1 8 217 208 5 E 342 210 211 4 348 210 0 1 0 0 0 E 218 0 1 1 1 0 0 0 0 0.0 0 334 0 4 E 340 0 2 E 0 334 340 0 0 -0.00064 0 0 26 0 1 1 1 1 1 4.0 2 349 210 219 3 350 210 211 220 219 1 351 211 212 221 220 1 356 357 217 227 226 1 358 218 228 227 217 5 E 359 219 220 4 366 219 0 1 0.0 0 E 228 0 1 1 1 0.0 0 0 0 0 0 350 0 4 E 357 0 2 E 0 350 357 0.0 -0.00064 0 0 27 0 1 1 1 1 1 4 0 2 367 219 229 3 368 219 220 230 229 1 104

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369 220 221 231 230 1 375 37 6 227 238 237 1 377 228 239 238 227 5 E 378 232 233 4 383 229 0 1 0.0 0 E 239 0 1 1 1 0 0 0 0 0 0 0 368 0 4 E 376 0 2 E 0 368 37 6 0 0 -0.00064 0 0 28 0 1 1 1 1 1 4 0 2 384 229 240 3 385 229 230 241 240 1 386 230 231 242 241 1 387 388 232 243 3 389 232 233 2 44 243 1 390 233 234 245 244 1 394 395 238 250 24 9 1 396 239 251 250 238 5 E 397 243 244 4 403 232 0 1 0 0 0 240 0 1 0.0 0 243 0 1 0 0 0 E 251 0 1 1 1 0 0 0.0 0.0 0 385 0 3 385 0 4 386 0 3 387 0 3 E 395 0 2 0 385 387 0.0 -0.00064 0.0 E 0 389 395 0.0 -0.00064 0.0 29 0 0 0 0 1 1 1.0 2 1 240 0 0 3 8 0 0 1 24 1 242 0.0 7 5 0 0 E 1 243 0 0 -3. 8 0 0 30 0 1 1 1 1 1 4 0 2 404 243 252 3 405 243 244 253 2 5 2 1 406 244 245 254 253 1 411 412 250 260 259 1 413 251 261 260 250 5 E 414 252 253 4 421 252 0 1 0.0 0 E 261 0 1 1 1 0 0 0 0 0 0 0 405 0 4 E 412 0 2 E 0 405 412 0 0 -0.00064 0 0 31 0 1 1 1 1 1 4 0 2 422 252 2 62 3 423 252 253 263 262 1 424 253 254 264 263 1 430 105

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431 260 271 270 1 432 261 272 271 260 5 E 433 262 263 4 441 262 0 1 0 0 0 E 272 0 1 1 1 0 0 0.0 0 0 0 423 0 4 E 431 0 2 E 0 423 431 0.0 -0.00064 0 0 32 0 1 1 1 1 1 4.0 2 442 262 273 3 443 262 263 274 273 1 444 263 264 275 274 1 451 452 271 283 282 1 453 272 284 283 271 5 E 454 276 277 4 4 60 273 0 1 0.0 0 E 284 0 1 1 1 0.0 0.0 0 0 0 443 0 4 E 452 0 2 E 0 443 452 0 0 -0.00064 0.0 33 0 1 1 1 1 1 4.0 2 4 61 273 285 3 462 273 274 286 285 1 463 274 275 287 286 1 4 64 4 65 276 288 3 4 66 276 277 289 288 1 4 67 277 278 290 289 1 472 473 283 296 295 1 474 284 297 296 283 5 E 475 288 289 4 482 276 0 1 0.0 0 285 0 1 0 0 0 288 0 1 0.0 0 E 297 0 1 1 1 0 0 0.0 0.0 0 462 0 3 4 62 0 4 4 63 0 3 4 64 0 3 E 473 0 2 0 4 62 4 64 0 0 -0.00064 0 0 E 0 466 473 0 0 -0.00064 0 0 34 0 0 0 0 1 1 1.0 2 1 285 0 0 -3. 8 0 0 1 286 287 0.0 -7.5 0.0 E 1 288 0.0 -3.8 0.0 35 0 1 1 1 1 1 4 0 2 483 288 298 3 484 288 289 299 298 1 485 289 290 300 299 1 4 91 4 92 296 307 306 1 106

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4 93 297 308 307 296 5 E 4 94 298 299 4 502 298 0 1 0 0 0 E 308 0 1 1 1 0.0 0 0 0 0 0 484 0 4 E 4 92 0 2 E 0 484 4 92 0 0 -0.00064 0 0 36 0 1 1 1 1 1 4.0 2 503 298 309 3 504 298 299 310 309 1 505 299 300 311 310 1 512 513 307 319 318 1 514 308 320 319 307 5 E 515 309 310 4 524 309 0 1 0 0 0 E 320 0 1 1 1 0 0 0.0 0.0 0 504 0 4 E 513 0 2 E 0 504 513 0.0 -0.00064 0 0 37 0 1 1 1 1 1 4.0 2 525 309 321 3 526 309 310 322 321 1 527 310 311 323 322 1 535 536 319 332 331 1 537 320 333 332 319 5 E 538 321 322 4 548 321 0 1 0 0 0 E 333 0 1 1 1 0 0 0 0 0.0 0 526 0 4 E 536 0 2 E 0 526 536 0 0 -0.00064 0 0 38 0 1 1 1 1 1 4.0 2 54 9 321 334 3 550 321 322 335 334 1 551 322 323 336 335 1 560 561 332 346 345 1 562 333 347 346 332 5 E 563 334 335 4 573 334 0 1 0 0 0 E 347 0 1 1 1 0.0 0 0 0 0 0 550 0 3 550 0 4 E 561 0 2 E 0 550 561 0.0 -0.00064 0.0 39 0 1 1 1 1 1 1.0 2 574 335 336 348 1 575 336 337 349 348 1 576 337 338 350 34 9 1 584 585 346 359 358 1 586 347 360 359 346 5 107

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E 587 349 350 4 593 E 360 0 1 1 1 0.0 0 0 0 0 0 574 0 3 575 0 3 E 585 0 2 E 0 574 585 0.0 0 .00064 0 0 40 0 1 1 1 1 1 1.0 2 594 349 350 361 1 595 350 351 362 361 1 596 597 352 353 364 363 1 603 604 359 371 370 1 605 360 372 371 359 5 E 606 363 364 4 609 E 372 0 1 1 1 0.0 0.0 0 0 0 594 0 3 595 0 3 596 0 3 E 604 0 2 E 0 594 604 0 0 -0.00064 0 0 41 0 1 1 1 1 1 1 0 2 610 363 364 373 1 611 364 365 374 373 1 612 613 366 367 376 375 1 617 618 371 381 380 1 E 619 372 382 381 371 5 E 382 0 1 1 1 0.0 0.0 0 0 0 610 0 3 611 0 3 612 0 3 E 618 0 2 E 0 610 618 0.0 -0.00064 0.0 42 0 1 1 1 1 1 1.0 2 620 375 376 383 1 621 376 377 384 383 1 622 623 378 379 386 385 1 625 E 626 382 389 388 381 5 E 389 0 1 1 1 0.0 0 0 0.0 0 620 0 3 621 0 3 622 0 3 E 625 0 2 E 0 620 625 0.0 -0.00064 0 0 43 0 1 1 1 1 1 1.0 2 627 385 386 390 1 628 386 387 391 390 1 629 630 388 393 392 1 E 631 389 394 393 388 5 E 394 0 1 1 1 0.0 0.0 0.0 0 627 0 3 628 0 3 108

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629 0 3 630 0 2 E 630 0 3 E 0 627 630 0 0 -0.00064 0 0 44 0 0 0 0 1 1 1.0 2 1 334 0 0 3 8 0 0 1 335 0.0 -7.5 0.0 1 348 0 0 -7.5 0.0 1 349 0 0 -7.5 0.0 1 361 362 0 0 -7.5 0.0 1 363 0.0 -7.5 0.0 1 373 374 0 0 -7.5 0 0 1 375 0 0 -7.5 0 0 1 383 384 0 0 -7.5 0 0 1 385 0 0 -7.5 0 0 1 390 392 0 0 -7.5 0.0 E 1 393 0.0 3 8 0.0 45 0 0 0 0 0 1 5 0 2 E 46 0 0 0 0 0 1 85. 0 2 109

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References AASHTO (1986), Standard Specifications for Transportation Materials and Methods of Sampling and testing, Part II: Methods of Sampling and Testing, 14th ed., American Association of State Highway and Transportation Officials Washington, DC., 1275 pp. Barrett, R.K (1995), Personal Communication. Bell, J.R., barrett, R K., and Ruckman, A.C. (1983), "Geotextile Earth Reinforced Retaining Wall Test," Glenwood Canyon, Colorado. Transportation Research Record 916, pp. 59-69. Eaton R A., Roberts, R.J. and Blackburn R.R. (1991) "Use of Scrap Rubber in Asphalt Pavement Surfaces," prepared for presentation at the ARA International Tire Recycling Conference, San Jose, California January 1991, 37 pp. Goodman, R.E., Taylor, R.L., and Brekker, T.L. (1968) A Model for the Mechanics of Jointed Rock," Journal of Soil Mechanics and Foundations, ASCE, Vol. 94, SM3, pp. 637-659. Humphrey, Dana N., Sandford, Thomas C., Cribbs, Michelle M., Gharegrat, Haresh G., and Manion, William P. (1992), Tire Chips as Lightweight Backfill for Retaining Walls Phase I, Department of Ci vii Engineering, University of Maine, pp 45-109. Izuka, A. and Ohta, H. (1987), "A Determination Procedure of Input Parameters in Elasto-Viscoplastic Finite Element Analysis, Soil & Foundation, Vol. 27, No. 3 pp. 71-87 Maine Department of Environmental Protection (DEP) (1989), Bureau of Solid Waste management, Report to Maine State Legislature on Waste Tires White Goods and Demolition Debris, May. Manion, William P., and Humphrey, Dana N., (1992), Tire Chips as Lightweight and Conventional Embankment Fill Phase I Laboratory, Department of Civil Engineering, University ofMaine, pp. 1-96. 110