Citation
Station Plaza

Material Information

Title:
Station Plaza
Creator:
Walter, Brian
Publication Date:
Language:
English
Physical Description:
65, [67] leaves : illustrations, charts, maps (some color), plans ; 30 cm

Subjects

Subjects / Keywords:
Buildings -- Remodeling for other use -- Illinois -- Evanston ( lcsh )
Terminals (Transportation) -- Designs and plans -- Illinois -- Evanston ( lcsh )
Office buildings -- Designs and plans -- Illinois -- Evanston ( lcsh )
Buildings -- Remodeling for other use ( fast )
Office buildings ( fast )
Terminals (Transportation) ( fast )
Illinois -- Evanston ( fast )
Genre:
Designs and plans. ( fast )
theses ( marcgt )
non-fiction ( marcgt )
Designs and plans ( fast )

Notes

General Note:
Submitted in partial fulfillment of the requirements for the degree, Master of Architecture, College of Design and Planning.
Statement of Responsibility:
Brian Walter.

Record Information

Source Institution:
University of Colorado Denver
Holding Location:
Auraria Library
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
13141399 ( OCLC )
ocm13141399
Classification:
LD1190.A72 1985 .W35 ( lcc )

Full Text
tlWIRONMENTAL DESirw mraria library
Stati on Plaza an archi tectural thesis presented to j, t the
Col 1ege of Design and Planning, University of Colorado at
Denver, in partial fulfillment of the requirements for the
Degree of Master o-f Archi tecture.
Brian Walter
May 1985
1


The Thesis o-f Brian Walter is approved.
Committee Chairman
Lf.
Pri nci pal
Advi sor
University of Colorado Denver May 1985


ACKNOWLEDGEMENTS
This program and design would not have been possible without the valuable assistance of:
Paul Heath Robert Kindig Dwayne Nuzum Rae Noritake Thomas Thompson Candace Schafer


TABLE OF CONTENTS
Acknowledgements..................................*.........3
Dedi cation............................................... 4
Introduction................................................6
Thesis Statements..........................................14
Project Description.................................... 16
HUMAN FACTORS
Activities........
Groups 8< Goals. Characteristics...
Social Forces.....
Policies and Codes
Attitudes.........
Qua!i ti es.......
17
21
23
24
25
27
28
PHYSICAL FACTORS
Locati on.........
Site Conditions... Building/Facility.
Systems...........
Servi ces.........
Functi ons........
Ci rculati on.....
Envi ronment......
EXTERNAL FACTORS
Zoning Map........
Zoning Ordinances. Permitted Uses.... Building Codes....
Soil Analysis.....
Cli mate..........
APPENDIX A APPENDIX B APPENDIX C APPENDIX D
DESIGN
Process
Final Presentation
4
44
46
47 50
52
53
56
57 63
BIBLIOGRAPHY


INTRODUCTION
Urban spaces exist because of the existance of human beings. Just as there are different human races there are different types of urban spaces. Are the human beings really different? No, the skin color may be different, but on the inside the basic elements that make up the individual, the number of chromosomes, the placement of organs, and the biological and chemical reactions that occur every within that body are the same. Are the urban spaces really different? This question is slightly harder to answer. It would be too general a statement to say that they are because they have activities associated with them, possess boundries, or are of a certain type. If one thinks in the realm of the abstract, it becomes evident that there exists only two types of urban space; transitory and object. In those instances when an object space also functions as a transitory space, a hybrid space is created. The hybrid space is not another type of space but rather, as a square is really a rectangle, the combination of the two basic types.
In its simplest form and in the simplest societies, i.e. a primitive society, the transitory space can be the path between two different elements in the society. This simple path is manifest in the simple street. This simple street can become more complex depending on activities that occur on or around it. When two major streets intersect each other, a special place is possible, and as was often the case in European and some American cities, a building of major importance was placed there.
As the activities along these simple streets became
6


INTRODUCTION
increasingly complex and the density around them greater, a new space developed. This space, I refer to as a buffer, pushed the street back and created a transition from it to the building. This can be seen in St. Andrea al Quirinale by Bernini. The space sets the building back to give it added prominence and still allows the normal street activities.
Another type of transitional space that developed from the simple street is the processional space. In this space, a ruler or other ranking individual, was afforded the opportunity to be seen in the best possible way.
The object space, or at least a pure abject space will always be harder to find. In a primitive society, the space could be the religious center where a member of the society went to pray and because of religious custom or mores, nothing more was permitted to occur there. Although these spaces may have been located in the middle of a social gathering area, and physical boundries absent, to merely
walk through was a very serious offense.
The object space in the modern American city is a
scarce resource indeed. This scarcity is the result of
incredibly high densities and the need for more places to
build because of them. The lakefront, with beaches and
parks, along the eastern edge of Chicago, is a vast open
space. At first impression this space might appear to be a
transitional space; the transition from the water to the
city itself. After more thought, especially on the subject
of how the lakefront is used in reality, it does in fact prove itself to be an object space. The inhabitants migrate
7


INTRODUCTION
to the 1 akefront in an effort to escape the city for a short time. They then venture back after having their fill of the space itself.
The hybrid space is one which has the two basic spatial types joined together. A classic example is Central Park in New York City. In addition to being an object space for people to escape the city, it also serves as a transitional space between two parts of the city. Those individuals that study the urban stage would probably yell in protest- over that last statement. The space was originally designed as an object space. Although this may be true, it is now a hybrid space.
The complexity of the urban space is largely dependent on the complexity of the activites of the society which created them. In the simple societies of primitive man, the gathering space functioned for all activities the society did; religious, governmental, and social. Commercial space as we know it did not exist because of the communal lifestyle of the society. As society became increasingly complex the activites associated with it also became more complex. This, in turn, led to the development of specialized spaces.
"If we think of prehistoric urban gathering space, which had many uses, as a prototype that still survives in simple communities everywhere, then we can begin to acknowledge how great an act of invention the walling off of a temple square was. The separation tells us, as it told the residents of E The ancient Greek ci vi .1 i zati on and society were more complex than that of Babylon. The activities were also more
a


INTRODUCTION
complex, and hence their urban spaces became more complex.
"The Greeks intermingled -functions by putting, the city treasury into chie-f and by having shrines and altars in the midst of government buildings like the council chamber. Because of this mingling, their urban spaces reflected a view of man's place in reality that was much more complicated than the view revealed by Mesopotamian cities."(2)
The activities that occur in an open space are determined by the social mores and codes of the society. If the
society is highly religious, then open spaces will be blocked off for the sole purpose of religious rites. If- the society has tremendous wealth and power, special places for leisure and entertainment will develop, as they did in the Roman Empire. The social mores will change over time in any society. In turn the activities will change which causes a change in open space. (This is why Central Park in New York City is now a hybrid space rather than an object space.)
"Christian sentiments after the fifth century put an end to theatres and amphitheatres. Economic and military necessity put an end to the chariot and horse races of the Stadium. But the baths persisted on a reduced scale until the fourteenth century, when the Black Death made social gatherings impossible for a while."(3)
If the complexity of the open space is a result of the activities that occur in it, what are these activities? Futhermore, what activities can be expected in today's society? The activities that seem to have carried throughout history are; religious, governmental, commercial, and social. There is no question that at times they have intermingled with one another or that one or more has lost importance to the others. These activities exist in all cultures, although they may affect the open spaces differently.
9


INTRODUCTION
You're walking down a tree lined street -from one block to the next. As you approach the intersection of the crossing avenue, you are bathed in warm sunlight. You cross, reenter into the shade o-f the tress and continue on your way. The activity is pleasurable and easy to understand. It also holds important in-formation concerning the architectural set up of an open space. The sunlight at the end of the street (or the begining of the next), shows the boundry of the space. An open space must have an indication that an individual is either in or out of the space. In otherwords, the open space must have its own identity or proof of it's exi stance.
The trees visually break down the distance between intersections. The scale isn't the trees per se, since they may be twenty feet apart, but rather the sunlight coming through the trees and the cast shadows of branches. The tress create a mosaic of light and dark on the sidewalk.
A space can be broken down in scale and still be unapproachable. A vast space of merely brick pavers is just as uncrossable as a football stadium that is empty. This is due to the scale of the space being broken down by elements that are too far apart in relative size. In order for an open space to be broken down into human scale elements, :i t is important that those elements, which break the scale down, do so in a smooth transitional manner.
The sidewalk is of course a hard materi iU yet it
doesn't make you shy away as would a sidewalk in many commercial districts. The trees provide the needed contrast


INTRODUCTION
between hard and soft edges or materials. The trees move and sway. In an open space, the soft qualities or amenities can be grass, trees, water, or any combination of them. If the entire space were o-f grass or trees it would lack another basic element in a good open space; di-f-ferent activity setti ngs.
As with the two basic activities, active and inactive, the activity settings will be of two types; a place to watch and a place to be watched. In the example used so far, a place to watch could be a porch on a house. The sidewalk and street areas are the reciprocal space, a place to be watched. Lunch hour is a good time to test for these types of spaces; are men watching women? Are women watching men? If these activities are occuring, then one of the necessary elements of an open space probably exists.
Even though there are only two activities, most people do them in different ways. For this, a good open space must possess different activity settings. These settings would allow an individual to sun bathe while watching others pass by or allow another to sit in the shade and talk with friends. The list, in actuality, is endless in terms of how people might use the space.
Earlier, in the discussion of space types (transit i onal obj ect and hybrid) it was mentioned that Central Park, although designed to be an object space, is now used as a hybrid space. This exemplfies another component of a
good open space; to be flexible enough to allow an evolution of activities or uses.
12


INTRODUCTION
In summary, a good open space will allow activities to occur in a rational, natural manner, as well as, letting them evolve and change. Futhermore, the space will have archi tectural effort (read designed into it) put into developing a sense of place, an entry, and its own identity. This can be achieved with an understanding of scale, proportion, materials, textures, and human behavior (how and why people do things). Understanding human behavior allows one to see that people doing basically the same things (active and inactive) do not do them in the same way. For this reason different activity settings are important, and why a good open space will have them. Finally, after the space is built, the designer should review it in use. Since there isnt a set formula for the design of a good open space, the design in use may not live up to all of the designers expectations. The designer should review it and make corrections if possible. To do this, isnt an admission of defeat or bad design, but rather fine tuning a design as would be done after a critique.
-l)From, "The Historical Development of Urban Open Space",an article by Dora Polk Chouch in Urban Open Spaces
13


Thesis Statements
The elements contained between or within the boundries of a transitional space will be the main determining factors of whether the project will be a success or not.
In my discussion of what made an open space good or bad, I didn't break the discussion into separate arguments for transitional space and object space. This is a result of my belief that the "rules" are the same. This particular statement deals with the transitional space specifically. Individuals going through the space will do so at there own pace. If the elements that make up the space do not permit this to happen it is not a good open space. If, however, the space contains those elements already discussed, and is designed with some intelligent thought and experimentation the space will make itself used.
The architecture bounding an open space will only enhance the character of the area. It will not make the space, nor will it prevent its use.
Lets start by assuming the open space is well designed using the techniques discussed. If the architecture is of poor quality, peolpe in the space will ignore it and enjoy themselves in the open area. If the architecture is very good, it will be noticed to be sure, but the space will be used on the same level as before. I believe this to be true, because the average person just looks at, they do not perceive their surroundingsan understanding of human nature.
Those spaces which are the most sucessful will be those
14


Thesis Statements
which don't try to change the traditional functions (activities) of the open space, but allow them to carry on and allow an evolution of new functions.
What is really being said is that the space should be socially responsive. Society inevitably changes, and the open space should be able to change with it.
15


PROJECT DESCRIPTION
The original Preservation League of Evanston Design Competition called for a proposed adaptive reuse of the existing train depot, a retail portion, a 300,000 sq. ft. office building and a civic plaza. This square footage would have easily exceeded the College's prefered limit of about 70,000 to 100,000 sq. ft.. Therefore this project contains the following:
1) Proposed adaptive reuse of the Davis St. Depot and its intergration into the project.
2) Civic or pedestrian plaza area.
3) Pedestrian links between the transit systems and between new development projects in the area.
4) Retail spaces up to 6:1 FAR.
5) Drop off and service areas as required.


HUMAN FACTORS
ACTIVITIES
ASCERTAINMENTS
-Eating in a restaurant in lower level of depot and northeast corner restaurant.
-Nightclub activity in northwest corner.
-Car rental on northern edge.
-Parking of autos in private parking lot at center of site.
-Dropping off / picking up of passengers on east and west edges.
-Transfering between buses and trains of various transit systems.
-High volume retail directly north of site.
-Low to medium volume retail and commercial east, south, and west of site.
-Vehicular activity around site with small percentage through the site.
PREDICTIONS
-Development around the site will bring increased activity around the site and will increase the activities associated with the mass transit systems.
RECOMENDATIONS
-Bring in activities which will be used through out the day.
17


HUMAN FACTORS
ACTIVITIES
ASCERTAINMENTS
-"Heaviest transfer volumes are between NORTRAN buses and CTA rail and buses. More than 500 riders per day transfer between NORTRAN routes 208, 212, and 213 and CTA rail and
bus routes. Of these transfers, about 85 percent are made to and from rapid transit trains and 15 percent to and from Evanston buses."(1)
-Diagram one indicates the estimated A.M. and P.M. peak hour transit patronage under current conditions.
PREDICTIONS
-Increased use of the transportation center site as a transportation hub and activity center is expected from several sources:
Clark Benson Project*
Downtown II*
Future fuel prices and availabilty*
A "universal transfer" program**
Diagram two presents an estimate of A.M. peak hour usage.
RECOMENDATIONS
-Increases in usage of the area should be designed for. In the case of transit use and transfering it is especially impotant to bring greater efficiency to the system.
-(1) taken from the repor t, Evanston Tr jjnsportat i.on Center Conceptual. PX.anni.ng and Desi.gn,0ct. 1980.
* Refer to Social Forces section.
** Refer to Policy and Codes section.
18


HUMAN FACTORS
-"Estimated patronage Transportation Center carriers, records, tant."(2)
ACTIVITIES
ASCERTAINMENTS
on existing transit routes serving the site was was determined -from survey, and on site observation by consul-
ARRIVING DEPARTING TOTAL
AM PM AM PM AM PM
NORTRN 150 100 280 250 430 350
CNW 210 400 620 200 830 600
CTA 490 330 280 480 770 810
TOTALS a so 830 1180 930 2030 1760
(3) Estimated transit patronage at
Di agram no.1 transportation center site.
(2) ibid.
(3) ibid.
19


HUMAN FACTORS
ACTIVITIES
PREDICTIONS
A.M. ONLY
ARRIVING DEPARTING
DOWNTOWN TRANSFER TOTAL DOWNTOWN TRANSFER TOTAL
NORTRAN 80 110 190 150 180 330
CNW 290 40 330 690 140 830
CTA (rapid) 480 200 880 190 150 340
CTA (bus) N/A 200 200 N/A 80 80
TOTALS 850 550 1400 1030 550 1580
EXISTING 850 - 1180
GROWTH 657. 347.
Diagram no.2 Forecast of peak hour patronage at the
(4)
transportation center.
-"Projected volumes would pertain to a time after implementation of the Clark-Benson and Downtown II development projects. If present plans progress as anticipated, the target period would be 1990-1995. The estimated number of arriving passengers at the Transportation Center site would be si>:ty~five per cent greater than at present (1980), while the number of departing passengers would increase by thirty-four percent(5)
- (4)ibid.
i ncreases
- (5)ibid.
Only A.M. forecasts were available but si mi liar can be expected for F'.M. peak hour patronage.


HUMAN FACTORS
GROUPS AND GOALS ASCERTAINMENTS
-Preservation League of Evanston: sponser of the original
competition. The F'.L.E. would like to see the rehabilitation and reuse of the Davis Street Depot because of its architectural merit.
-City of Evanston and the City of Evanston Planning Office: The concerns of these groups lie in the development of an underdeveloped area. In addition to increased tax revenues (especially with Downtown 11), relief from what is considered an eyesore in Evanston is hoped to be gained.
-The CTA and CNW: It is hoped that by improving on the
efficiency, comfort, safety, and convience of transit uses, more peolpe will be attracted to public transportation.
PREDICTIONS
-It is believed that the current research park concept (university and private industry research area) of Downtown II, "would generate 8,600 jobs and millions of additional property and sales tax dollars for the city."(6)
RECOMENDATIONS
-By reusing the existing depot, its architectural response with the new construction could help communicate the mixed use character of the area.
-Additionally, by reusing the depot service interruption to the CNW at this stop could be kept to a minimum.
(6)From,"Research Park Aim of City, NU for Downtown Site",
an article in the March 15,1984Evanstgn Review, by Tom Lassi ter.
21


HUMAN FACTORS
GROUPS AND GOALS ASCERTAINMENTS
-Carley Capital Group: The development group which is/has invested funds for the Downtown II and Clark Benson projects. They, would of course like to see a return on their investments, but have worked closely with city, public, and university officials in hopes of satisfying all concerned parties. They hope to achieve a quality development.
-Users of transit services and the general community: The transit patrons would like to see the area improved because this site is perfectly suited for all transportation needs (transfering, arriving, and departing). The community would,"...enjoy national visibilty generated by the research park"(7) and would recieve, "better promise for successful redevelopment of the downtown area an aim which has eluded the city for years."(8)
PREDICTIONS
-"...The emphasis has been placed on people rather than vehicles."(9)This will surely help in the sucess of the redevelopment projects concerned and is most important to the sucess of the transportation center project.
-"The major benefits derived from the Transportation Center would be enhancement of the area, passenger amenities, improved comfort and convenience, etc. For the thousands of people who traverse this area daily, however, and many more who will be attracted by new downtown development, improved accessibilty to public transit and relief from the present unslightly conditions would be added incentive to use public transportation."(10)
-The current set of goals and objectives, which should remain fairly constant for the seeable future, seem to satisfy all concerned and are realistic and attainable.
RECOMENDATIONS
-The conceptual design proposals from the report, Evanston Transportation Center Site Conceptual Planning and Design, should be used as starting point for the designer. This report was made up with the goals and objectives listed above as a basis for the conceptual design.*
(7) ibid.
(8) ibid.
(9) taken from the report, Evanston IC5Q5EQCtiiti.gn Center
Hit ELeqqLqq EQd. 0ct.,i980.
(10) ibid.
* The conceptual design proposal is listed in Appx. A


HUMAN FACTORS
CHARACTERISTICS
ASCERTAINMENTS
-Presently, the majority of the users of the site are commuters and transit passengers. They are varied
ethnically, socially, economical 1y, and racially. A slightly greater percentage of the consumers are white collar job holders going to or returnig from jobs in downtown Chicago.
PREDICTIONS
-The proposed developments, DOWNTOWN II and Clark-Benson, would undoubtly bring in more users to the site. The difference between white collar and blue collar workers would increase in favor of the white collar worker. The largest increase in users would come from individuals going to shop, eat, or relax at the site because of the increase in possible activities. This increase would be made up of people living in Evanston and Northwestern University students.
RECOMENDATIONS
-Because of the diversity in character!stics of the users it is important that the architecture be "democratic". By this it is meant that each individual will be able to experience the area in his or her own way. (In other worcds the creation of a "Villa Italia", specific to one group, would probably be inappropiate.)


HUMAN FACTORS
SOCIAL FORCES ASCERTAINMENTS
-Currently the ex i stance of any real social -forces to use the site are not apparent, although previous thinking about the site as being "vehicle -friendly" have been replaced with it being "user friendly" and becoming a, "...lively 'station plaza' traditional1y found in American communities during the heyday of passenger railroads and srill flourshing in European communities."(11)
-A shortage of parking in the CBD now exists. This shortage seems to have little if any effect on the usage of the site, although it should seem to bring about an increase.
PREDICTIONS
-"The impetus for increased transit service would derive from additional development in downtown Evanston. The following potential projects would be of particular signigica-nce in this respect.
Clark-Benson:A multi-use development including office and retail facilities and condominiums.
DOWNTOWN II: An extensive mixed-use project which could include office and retail space and dwellings as well as the Transportation Center.
"Implementation of these projects would more than double
the amount of office space in downtown Evanston and would result in an increase of more than forty percent the floor area devoted to retail uses. The number of residential units in the greater CBD area would increase from 1700 to about 2700, or by approximately sixty percent12)
"While these comprise an ambitious program, it is also inevitable that other development will occur. The effect of presently unforseen development would be to further increase activity at the Transportation Center."(13)
-"The consquences of future fuel pricing and availability are not yet clearly discernable. Most planners, however, forsee an increase in the use of public transit, particularly for home-to-work trips. It is probable, therefore, that the Transportation Center would experience further increased usage as travel habits change."(14) 11
(11) ibid.
(12) ibid.
(13) ibid.
(14) i b i d .
24


HUMAN FACTORS
POLICIES AND CODES ASCERTAINMENTS
-Between the various transit systems (CNW, CTA, and NOTRAN) there lacks a policy which would permit ease of movement between the different lines.
PREDICTIONS
-"A 'universal transfer1 program has been proposed for near-term implementation in the Chicago metropolitan area. Among other movements, this would allow free transfers between CTA and CNW services at the Evanston Transportation Center. The number of such transfers cannot be accurately forecast with the data at hand, but it is apparent that some passengers would find downtown Evanston a convient location to change travel mode."(16)
RECOMENDATIONS
-If the proposed "universal transfer" program becomes a reality (and even if it doesnt) a direct link between CNW and CTA terminals should be provided. This link would improve efficiency in either case.
(16)ibid.


HUMAN FACTORS
POLICIES AND CODES ASCERTAINMENTS
-"There is a present policy of the regulations which permits a discount to developers to provide only -forty to sixty percent o-f the required parking spaces -for developments located in specified sections of the CBD core area."(17) Unfortunatley the City has not provided the parking necessary to make up for the discounts. It would appear that this would be an added incentive to use public transit to reach destinations in the CBD; it isnt.
PREDICTIONS
-The attitudes which the community has regarding public transit in the area is the major block in this particular problem.
RECOMENDATIONS
-Change the public's attitudes about public transit in the area through architectural means.#
(17)Taken from a summary report, EVANSJON CBD PARKING AND TRAFFIC SILJDY, Oct. 1979, pg. 3.
*The existing attitudes concerning public transit in the area may be found in the section entitled "Attitudes".
26


HUMAN FACTORS
ATTITUDES
ASCERTAINMENTS
-These three questions (18) were used in parking and transit questionnaires used in the EVANSTON CBD PARKING AND TRAFFIC STUDY.
Q. Which problem and inconvience do you associate with
walking downtown?
R. Danger -from traffic
Long waits for traffic No weather protection Requires more time Q. What changes would infl
downtown?
RANKING PERCENTAGE
1 20. 6
n Xm 15.5
3 14. 7
7 4. 4
e you to walk more in
RANKING PERCENTAGE
R. Increase physical comfort 1 25.8
Make route more attractive 18. 8
Make destination more acessible 16. 4
Make walk shorter 4 9. 4
Q. What can be done to improve walking envi or meri t
encourage more use?
RANKING
PERCENTAGE
R. Provide weather shelter Provide more stores/rests, Provide more sitting and resting places Provide street malls
31.1 22.7 8o
6.8
RECOMENDATIONS
-From all three questions, it appears that protection from weather or physical comfort is important to the users. This is "in line" with the goals of the CTA, CNW, and NORTRAN systems. The use of covered walkways and heated waiting areas is imperative.
-The city wanted, as a goal, to improve the poor visual quality of the site. This is again in line with user opinion. Open plazas or enclosed atriums are possible solutions to this problem and would also provide sitting and/or relaxation areas.
-The transit passengers didn't mind if it took extra time with walking downtown (automobile drivers ranked it number two with 14.4 percent (19)). This indicates that the transit area itself is what is causing a lack of use.
(18)ibid.
(19)ibid.
27


HUMAN FACTORS
QUALITIES
ASCERTAINMENTS
-Cam-fart: Under present conditions transit patrons are
forced to stand or sit in unheated waiting areas until their train, bus, or ride arrive. Those transfering between CNW and CTA must walk to their destination exposed to the given weather conditions. In the winter months this walk can be extremely hazardous because of the sites proximity to the lake and its effect on weather (Lake Effect).
-Efficiency: Because there isnt a direct link or even a
straight line between the Davis Street Depot and the CTA terminal, transfering patrons must walk around using Davis or Church Streets.
RECOMENDATIONS
-Comfort: Enclose the route between CTA and CNW stations to
provide protection from the elements. Waiting areas which are heated and/or enclosed would be a welcome addition to those who are forced to wait outside.
-Efficiency: A direct walkway between the two stations, as
described in the conceptual designed proposed in the competition program. Additionally, this direct link would be an excellent tool if the "universal transfer" program became reality.
28


HUMAN FACTORS
QUALITIES
ASCERTAINMENTS
-Security: The area, although not a very high crime area, is not a good place to be night. The stairs -for CNW platforms are unlit (a safety hazard as well) do to vandalism. Street lights exist but do not seem to help in making one feel secure. The CTA station is well lit inside but there is very little light on the outside. The CNW station had no lights on when I visited the site.
-Safety: Because the CNW station is in a state of disrepair
it really is a safety hazard. Rotten wood on the platform is easily stumbled on. Unlit stairwells are extremely difficult to neogotiate past sunset. In the winter time falls on icy sidewalks are not uncommon.
RECOMENDATIDNS
-Security: Increase lighting to provide less dark areas. If
the plaza is designed well, and activities which go on throughout the day and evening are brought in this should help "secure" the area.*
-Safety: Aside from rehabilitating the Davis Street Depot,
the covered walkways would be a major step in the right di recti on.
*This recomendation is based in part on chapter six,"The
Undesi rabl es", f rom, The Social. Life of Smaff Urban Spaces, by William H. Whyte.


HUMAN FACTORS
QUALITIES
ASCERTAINMENTS
-Access: Access to the site is relatively easy -for vehicles, transit vehicles, pedestrians, and bicyclists.
-Convenience: The site is located ideally -for those comin
to the CBD, transfering to or from the CNW, or using th CTA services.
RECOMENDATIONS
-Access: To improve access signage would help direct
commuters and in turn possibly avoid confrontations between pedestrians and vehicles.
a> gj


HUMAN FACTORS
COMFORT
EFFICIENCY
SECURITY
SAFETY
ACCESS
CONVIENCE
QUALITIES
ASCERTAINMENTS
^ !/ 'Sj ^ ^ d* '.b *Jj d d d d ^ ^ ^ ^ ^ ^ ^ * Jp
#
V P B A A G E
E 0 E V B 0 X
R 0 L. G. V. 0 E
Y R A A D C
P. V V
G. G.
31


PHYSICAL FACTORS
LOCATION-RELATION TO CHICAGO


AVENUE
PHYSICAL FACTORS
LOCATION-COMMUNITY
ASCERTAINMENTS
-From City of Evanston Planning Office
J £> anNJAV t


PHYSICAL. FACTORS
L.OCAT I ON-COMliUN ITY PREDICTION
34


PHYSICAL FACTORS
SITE CONDITIONS-SURROUNDING AREA-PHOTOS


PHYSICAL FACTORS
SITE CONDITIONS-SURROUNDING AREA-PHOTOS
36


PHYSICAL FACTORS
SITE CONDITIONS
ASCERTAINMENTS
-From City o-f Evanston Engineering Department,
o /


PHYSICAL FACTORS
SITE CONDITIONS-PHOTOS
33


PHYSICAL FACTORS
BUILDING/FACILITY ASCERTAINMENTS
-The Davis Street Depot is in rather a bad state. This is the result of several things. Since the structures intended purpose, passenger and freight service, has become obsolete, not much in the way of preventive maintance has been done. The lack of maintance shows in rotten wood stairs and staircoverings, graphetti, loose and or fallen slate shingles, and concrete that is cracked and getting worse.
Architectural1y, the building is a good example of Burnham's ideas concerning the train in the city. The track is elevated from street level to aleviate some of the problems of noise, dirt, and congestion with traffic. The massing is rather simple, but a clarity of design comes through the spartan detailing. The main floor acts as a base for the building and elevates the important space of the structure, the waiting areas, to the track leveL. The differance in the importance of the two spaces is revealed by the use of brick at the upper level and concrete at the lower level.
-Refer to Appendix B for additional information concerning the Davis Street Depot.
39


PHYSICAL FACTORS
BUILDING/FACILITY-PHOTOS ASCERTAINMENTS
40


PHYSICAL FACTORS
BUILDING/FACILITY-PHOTOS ASCERTAINMENTS
41


PHYSICAL FACTORS
BUILDING/FACILITY
ASCERTAINMENTS PLANS,ELEVATIONS,SECTIONS


PHYSICAL FACTORS
SYSTEMS-LIGHTING
ASCERTAINMENTS
-As mentioned in the "qualities" section of this document, the lighting that exists is poor -for not only safety reasons, but also from a design aspect. The lighting is typical city lighting with no attempt to bring intereset into the site at night.
RECOMENDATIONS
-Use lighting to accent entries or other major focal points. Additionally, signage, both lit and unlit would help in directing users to their destinations.
-Lighting for safety and security mist be increased to help foster a comfortable feeling for the area.
43


PHYSICAL FACTORS
SERVICES-WATER SUPPLY ASCERTAINMENTS
-From Evanston's engineering department.
44


PHYSICAL FACTORS
SERVICES-STORM DRAINAGE ASCERTAINMENTS
-From Evanstons engineering department.
45
?a y


PHYSICAL FACTORS
FUNCTIONS
Depot is Its primary
-The CNW service. station.
-The parcel is now a private either the CNW or -Hours of operation
ASCERTAINMENTS
no longer used for passenger or freight function at this time is that of a commuter
of land directly east of the depot (the site itself)
parking lot. It provides no direct access t
CTA systems.
CNW 5:00am to 12:00am Monday - Friday
CTA trains 5:00am to 2:00am Monday - Friday
8:00am to 10:00pm Sat. and Sun.
buses 5:00am to 2:00am everyday
Nortran 7:00am to 8:00pm Monday - Friday
RECOMENDATIONS
-The hours of operation cover the normal hours of most businesses. It is obvious to see that the types of retail or
business to be brought in should have a wide spread of operating hours so that there will always be some activity in the plaza area.
46


PHYSICAL FACTORS
CIRCUL AT I ON-F'EDESTR I AN ASCERTAINMENT
47
4 AVENUE


PHYSICAL FACTORS
CIRCULATION-VEHICULAR ASCERTAINMENT
48
| AVKNUC


PHYSICAL FACTORS
CIRCULATION-PEDESTRIAN PREDICTION
49
rrr-r. 7>


PHYSICAL FACTORS
CIRCULATION-VEHICULAR PREDICTION
50


PHYSICAL FACTORS
ENVIRONMENT
ASCERTAINMENTS
Visually: The depot is in a state of disrepair and needs quite a bit o-f work to be just presentable. Rotten wood, extremely weathered paint, and graf-fitti are serious problems. The CTA station is just plain beaten up, and the surrounding earth berms are usually trash filled.
Accoustical 1y: Auto traffic and general street noise are not a serious problem here. The CTA Rapid Transit trains, although not a continous source of noise can become an annoyance unless filtered out.
RECOMENDATIONS
Visually: Depending on what is to be done to the earth berms, a change os spieces is in order. The new plantings should be thick to keep trash out and easily cleaned. Futhermore, the "evergreen" variety would bring some color into a otherwise drab site.
The depot will need quite a bit of restoration in order to be aesthically pleasing. The adaptive reuse will of course change the building somewhat, but it should maintain the character it originally had.
Accoustical 1y: A buffer of some sort between the CTA track area and the site will take the edge off the noises produced by the trains. It is impossible to elimainate all of the sound from the trains and in fact could be used in the design process.
51


EXTERNAL FACTORS
ZONING MAP ASCERTAINMENTS


EXTERNAL FACTORS
ZONING ORDINANCES ASCERTAINMENTS
-General Requirements:
-All business, service, storage, merchandise, display, and repair processing, where allowed, shall be conducted only within completely enclosed building except -for off street automobile parking, off-street loading, open sales lots, automobile service stations, drive-in facilities and drive-in restaurants, vending machines and restaurants in the districts where such uses are allowed.
-The conduct of sales as permitted herein shall be subject to the following restrictions:
-Any structures or apparati which are to be placed on the public right of way in conjunction with the exception granted herein shall be situated so as to facilitated continued easy access to and travel on said sidewalk for its entire length by pedestrians, i.e., said structures shall not be situated or constructed in such a manner as to present any physical threat to pedestrians traversing the public way in the vicinty of said structure.
-The applicant shall submit to the City
evidence of insurance in the amount of $100,000.00/$300,000.00 over any sale for
which application is made hereunder, with the City being named as co-insured thereon.
-No applicant hereunder shall conduct a sale at any time other than betweent the hours of nine oclock a.m. and nine oclock p.m. on any day pursuant to an exception granted hereunder. -Each temporary exception so granted shall be in writing and a copy thereof, together with the application and any supporting documentation, shall be transmitted to the Director of Inspections and Permits to be maintained amoung the records of that Department.
-The production of any goods on the premises shall be clearly incidential to the principal retail or service use and shall be sold at retail, primarily on the premises, unless otherwise specifically provided herein.
-Within a business district, goods offered for sale by any business establishment, except an antigue store or resale shop for apparel and accessories, shall consist of not less than sevent-five percent new merchandis and not less than seventy-five percent of the total sales volume shall consist of -Taken in whole or in part from the Zoning Ordinances of the City of Evanston (Revised 5/84)


EXTERNAL FACTORS
ZONING ORDINANCES
ASCERTAINMENTS retail sales on premises.
-Processes and equipment employed, and goods processed or sold, shall be limited to those which are not objectionable by reason of odor, dust, smoke, cinders, gas, noise, vibration, re-fuse matter or water-carried waste.
-When a business or commercial district adjoins a residence district, yards shall be provided in accordance with the regulations set -forth in each o-f the business and commercial districts.
RECOMENDATONS
-The immediate concern has to do with the permitted times of selling that the zoning ordinances specify. A varience of some sort would be needed to allow the retail areas of this project to sell at times earlier than what is permitted.
-Taken in whole or in part from the Zoning Ordinances of the City of Evanston (Revised 5/84).
54


EXTERNAL FACTORS
ZONING ORDINANCES ASCERTAINMENTS
-Floor Area Ratio:
-In a B-5 District, not to exceed 6.0 except, the gross floor area may be increased by four square feet for each square foot of open space provided on the lot and by two square feet for each square foot of arcade area, but in no case shall the total floor area ratio permitted by these premiums exceed 7.0.
-Open space shall be defined as a plaza or other area, suitably paved and landscaped, open to the sky and adjacent to a public street. Such area shall not be used for business or commercial purposes or for parking, loading or vehicular access.
-An arcade shall be defined as a covered area adjacent to or connecting with a public street or an open space. Said arcade shall be open on at least one end available for pedstrian traffic at all times. It shall have a clear height of at least twelve feet, a minimum width of not less than eight feet and the maximum width which may be used in computing the floor area premium set forth above shall not exceed twenty feet.
-Building Height:
-In a B-5 District, not to exceed eighty-five feet.
-Taken in whole or in part from the Zoning Ordinances of the
City of Evanston (Revised 5/S4)


EXTERNAL FACTORS
PERMITTED USES
ASCERTAINMENTS -Amusement establishments.
-Antique stores.
-Bakeries.
-Banks and other -financial institutions, not including drive facilities.
-Book and stationary stores.
-Child care services intended primarily for the care of children of patrons of the business area.
-Clothes pressing establishments.
-Clothing stores.
-Department stores.
-Drug and pharmacies.
-Fast food restaurants.
-Flower shops and conservatories.
-Gift shops.
-Newsstand and agencies.
-Package liquor stores.
-F'hotographic studiosincluding development and printing of photographs when conducted on the premises as a part of a retail business.
-Restaurants.
-Tailor shops.
-Ticket agencies.
-Travel bureaus.
-Taken in whole or in part from the Zoning Ordinances of the
City of Evanston (Revised 5/84).
-These uses do not comprise the entire list of permitted uses but rather what is felt would be most beneficial to the proposed project.
56


EXTERNAL FACTORS
BUILDING CODES ASCERTAIMENTS
-Codes applying to use groups perimitted in a B-5 District, which could exist in the retail or transit terminal portions of the project.
-Use groups permitted:
-Use Group A-Public Assembly.
-Use Group B-Business.
-Use Group F-Factory.
-Use Group M-Mercanti1e.
secti on
312.0
401.0
516.0
CODES COVERING ALL PERMITTED USE GROUPS
page
TYPES OF CONSTRUCTION
Mixed use and occupancy 69
Construction classification 71-76
Special historic buildings and disticts , 92
ALLOWABLE AREA AND HEIGHT
505.0
506.0
507.0
509.0
General area and height limitations 80-
Area exceptions Unlimited areas
Height exceptions -83
FIRE SEPARATIONS
1403.0
1407.0
1409.0
1410.0
1412.0
2112.0
Fire resistance tests 290-292
Fire walls and party walls 298-299
Fire separation walls 300-
Vertical shafts -302
Fire resistance rated flaor/roof/ 303-
ceiling assemblies -304
Elevator opening protectives 395
EXTERIOR WALL PROTECTION
1406.0 Exterior walls
1414.0 Exterior opening protectives
2902.0 Glazing of unprotected areas
FIRE LIMIT REQUIREMENTS
296-298
304-305
420
502.0
503.0
1426.0
Restrictions within the fire limits 77-
Restrictions outside the fire limits -79
Roof Structures 317-320
FIRE RESISTANCE
1402.0 Fire hazard classification 290
1403.0 Fire resistance tests 290292 1403.3 Opening protectives 291 1403.5 Fire retardant wood 292 -The information supplied here lists the section number,
title, and page number where it could be found in the 1981 edition of the BOCA code. Any architectural design which has a code pertaining to it here or not, should still be throughly checked in a complete BOCA (1981 edition).
57


EXTERNAL FACTORS
1405.7
1411.0
1412.0
1413.0
1416.0
1420.0
1426.0 1426.3
1427.0
1608.0
1404.0
1421.0
1422.0
806.0 807. 0 808.0
809.0
810.0 811.0 812.0
814.0
816.0 817. 0 818.0
819.0
823.0
824.0
2109.0
1702.0
1704.0
1711.0
1713.0
1714.0
1718.0
1410.0
1420.0
BUILDING CODES
ASCERTAINMENTS FIRE RESISTANCE cont.
Grade -floor protection Fire resistance of structural mbrs. Fire resistance rated floor/roof/ ceiling assemblies.
Roof construction
Fire window and shutter
Fire stopping and draft stopping
Roof Structures
Skyli ghts
Roof coverings
Refuse vaults
294
302-
-304
306
309-311
317-320
317
320-321
INTERIOR FINISH
Flame spread and resistance tests Interior finish and trim Application of interior finish MEANS OF EGRESS
292293
311-
-315
Occupant load 151-
Types and locations Capacity of exits Number of exits
Exit access passageways and corridors Grade passageways used as an exit
Means of egress doorways -160
Horizontial exit 161-
Interior exit stairways Access to roof Smokeproof inclosures
Exterior exit stairways -170
Exits signs and lights 172-
Means of egress lighting -173
Elevator exit restrictions 295
FIRE PROTECTION SYSTEMS
Fire supression systems Water sprinkler systems Standpipe systems Fire department connections Water supply and other exting. Supervi si on
VERTICAL OPENINGS
media
336-339
341-342
347-349
350-
352
355-356
Vertical shafts 301302
Firestopping 309-311
58


EXTERNAL FACTORS
2108.0
600.5
600.6
605.0
607.0
704.0
706.0
711.0
1410.0
2405.0 Appx A
515.8 1317.0 ART 22
ART 20
515.0
ART 25
BUILDING CODES
ASCERTAINMENTS VERTICAL OPENINGS cont.
Hoistway enclosures and venting HAZARDOUS AREAS
Equipment rooms Segregation of storage spaces Existing buildings Pyroxylin plastics
LIGHT AND VENTILATION
Artificial light and ventilation Natural lighting and ventilation Bath and toilet rooms Vertical shafts Skylight assemblies Referenced standards SANITATION
Access to plumbing fixtures Protection from termites and decay Plumbing Systems
ELECTRICAL WIRING
Electrical wiring and equipment HANDICAPPED
Physically handicapped and aged ENERGY CONSERVATION
Energy conservation
393-394
93-
-94
96
96-99
140
141-142
143-144
301-302 - 423
90-91
282-284
405-409
377-381
88-92
427-438
59


EXTERNAL FACTORS
BUILDING CODES-GROUP A
section ASCERTAINMENTS page INTERIOR FINISH
1424 Decorative material restrictions 316 FIRE RESISTANCE
1405.5 1425.4 Truck loading and shipping areas 294 Balconies 316 MEANS OF EGRESS
617.0 812.5.4 FIRE PROTECTION SYSTEMS
1717.0 Manuel -fire alarm systems 354-355 VERTICAL OPENINGS
631.0 Open wells 135-138 HAZARD AREAS
603. 1 Inspections 95 MOTION PICTURE PROJECTION ROOMS
608.0 Use and storage o-f -flammable -film 99-102 STAGES AND PLATFORMS
617.6 617.7 Stage enclosure walls 114 Stage -floor construction 114
60


EXTERNAL FACTORS
BUILDING CODES-GROUF' B ASCERTAINMENTS
section FIRERESISTANCE page
1425.4 Balconies MEANS OF EGRESS 316
809.3 Buildings with one exit FIRE PROTECTION SYSTEMS 155
ART 17 Fire protection systems VERTICAL OPENINGS 335-356
631.0 Open wells 135-138
61


EXTERNAL FACTORS
sect!on BUILDING CODES-GROUP F ASCERTAINMENTS FIRE RESISTANCE page
1425.0 Exterior trim restrictions HAZARD AREAS 316-317
604.0 Special permits o-f -fitness 95-96
611.0 Paint spraying and spray booths 104-105
612.0 Dry cleaning establishments LIGHT AND VENTILATION 106-107
1606.0 Drying rooms 331
62


EXTERNAL FACTORS
section 630. 0
1405.4
1425.0
630.0
1702.0
70S. 0
BUILDING CODES-GROUF' M ASCERTAINMENTS
SPECIAL USE AND OCCUPANCY REQTS Covered mall buildings FIRE RESISTANCE
Packing and shipping rooms Exterior trim restrictions MEANS OF EGRESS
Covered mall buildings
FIRE PROTECTION SYSTEMS Fire supression systems
LIGHT AND VENTILATION
Business and work rooms
page
131-135
316-
131-135
336339
143
63
Cl 10


EXTERNAL FACTORS
SOIL ANALYSIS-SUNNARY ASCERTAINNENTS
-Gray, very stiff, silty clay at 18 -ft. to 24 ft.
-Saturated silt at 24 ft. to 25.5 ft.
-Gray, soft to medium, silty clay with a water content near 30 percent and an unconfined compressive strength of around 0.5 tsf (1,000 psf) at 25.5 ft. to 54 ft.
-Nedium to stiff silty clay with a water content of approximately 20 percent at 54 ft. to 70 ft.
-Hard, gray, sandy clay (hardpan) with a water content near 10 percent, dry density of over 130 pcf, and unconfined compressive strengths of over 6.5 tsf (13,000 psf) at 70 ft. to 91 ft.
-Extremely dense, gray, gravelly, fine to coarse sand at 91 ft. to boring termination at 91.5 ft.
-Hand auger probes were used on the railway embankment (CNW Line) to a depth of 6.5 ft. These probes indicate brown sandy sand fill.
-Water level was noted at approximately 7 ft.
REC0NENDATI0NS
-Foundations:
-Caissons to a depth of 70 to 75 ft. with a net allowable soil bearing pressure of 25,000 psf. Caissons should not exceed 85 ft. because of possible inundation of caisson shaft if the water in the granular deposits below this depth is water under artesian pressure.
-Exterior pavements:
-Suggested removal of unsuitable surface fill materials to 2 ft. below the designed pavement subgrade.
-Taken in whole or in part from a soils report produced for
the Shand, Norahan Co., Inc., project located directly northwest from the northwest corner of the site. The report was produced by STS Consultants Ltd. and may be found in its entirety in Appendix C of this program.
64


EXTERNAL FACTORS
CLIMATE
ASCERTAINMENTS
-The -following inf ormation, unless otherwise noted, is taken from an observation point at O'hare International Airport, located about 15-20 miles west o-f the site.
-According to the citys engineers, the architects o-f the area do not have a standard source o-f in-formation for climatic data in Evanston.
Mean Temperature (F)
J F M A M J
22.9 26.1 35.7 48.8 58.4 68. 1
J A S 0 N D
71.9 71.1 63.7 53.8 39.3 27. 1
Annual Mean 48.9
Precipitation Normals (in. )
J F M A M J
17.3 13.4 25.2 33.9 34. 1 41.7
J A S 0 N D
34.3 26.9 30.1 22.9 21.0 16.3
Annual F'reci pi tat i on 31.72
Cooling Degree Day Normals
J F M A M J
0 0 0 0 35 138
J A S 0 N D
221 207 51 12 0 0
Annual 1y 664
Heating Degree Day Normals
J F M A M J
1305 1089 908 486 240 45
J A S N D
7 18 90 360 774 1175
Annual 1y 6497
RECOMENDATIONS
Understanding the "Lake Effect" (generally higher humi di ty,
more snow, and bigger wind chills) is cri ti cal to the
design of this project. The above figures should be taken
as mini mums.
-More information may be found in Appendix D of this program.
-Taken from NOAA, Environmental data service publications.
65


APPENDIX A









IV. CONCEPTUAL DESIGN PROPOSAL
A. Planning Criteria
The conceptual design -For the Evanston Transportation Center and, more inclusively, -for the city bounded by Church Street, Benson Avenue, Davis Street, and Maple Avenue, generally reflects planning criteria which are similiar to those established -for and used in the preparation o-f earlier Transportati on Center studies. However, the appication o-f these criteria has now resulted in a distinctly different planning and design emphasis.
While prior design schemes envisioned the primary use of the site, and the purpose of the Transportation Center, to accomodate transit vehicles, the proposed design emphasises the convenience, comfort, and safety of transit passengers boarding, leaving, or transferring between the various carriers serving downtown Evanston.
A preliminary analysis of passenger movements indicated that such movements could be accomodated more conveniently, more safely, and more economically if the street level of the site could be kept free of penetration by transit vehicles. This analysis was based on the assumptionthat adequate bus berthing positions would be available on the perimeter streets, paricularly on Benson Avenue, to meet the needs of CTA and NORTRAN bus passengers. This assumption was later verified and the proposed design concept, taking in the total block, evolved into a people- orientated facility, served at its periphery by the various transportation systemson their own right-of-way and on existing public


streets.
B. Conceptual Design Development
The block to be occupied by the Transportation Center is the southernmost block of Downtown II, a mixed-use development proposed tor the area extending north from Church Street to Emerson Street and bounded on the west and east by the CNW and CTA rights-ot-way, respectively. Thertore, it appeared opportune to try to meet, within this block, not only the functional goals of the City of Evanston, but to create a strong south anchor for development by joining the Transportation Center to office building, retail facilities, and public spaces which reflect the multi-use character of Downtown II.
The decision to avoid penetration of the site with roadways and not to design a vehicle terminal on the site, but rather to continue making use of existing streets for vehicular movement and bus passenger loading made possible the development of the design concept of linking the CNW and CTA rights-of-way at grade level and at track level in a simple, direct, and economical manner.
This design approach while requiring acquisition of East Railroad Avenue, a private street owned by CNW, would preserve most of the land contained within the triangle farmed by the railroad embankments, and would allow the development of such land facilities, and future devleopment plans for the remaining site could be phased to meet overall development goals of the City of Evanston.


C. Proposed Conceptual Design Site
The drawings presented in this report indicate one passible development scheme -for the total site, including the Transportation Center, and office tower, a rehabilitated CNW station for commerical occupancies and a civic plaza.
This development would be accessible to pedestrians from all surrounding streets and, by way of a sky-walk, from upper level pedestrian walkways of Downtown II. Vehicular access would also be available at all surrounding streets. Service vehicles would enter and exit the development along Church Street and operate below plaza level. Taxis and autos dropping off and picking up passengers would enter and exit the Transportation Center at Davis Street.
Other locations where private vehicles could discharge or board passengers would be provided along Maple Avenue and Church Street. Entering and exiting traffic lanes serving the office building garage would be located along Church Street.
Transit passengers would approach and depart the Transportation Center and the commercial development either as pedestrians, as passengers in private vehicles or taxis, or as passengers in buses, rapid transit trains and commuter trains. Thus, the Center would function as a terminal as well as a transfer point between carriers.
D. Proposed Conceptual Design Transportation Center
The street level concourse of the Center would extend in an east west direction between the CTA and CNW embank-
ments. Its location was selected to coincide with the aline-


merit of the existing CTA station passageway below the rapid tracks and the existing CNW station. Proposed as a generous, two-story high, skylit space, the concourse would provide a comfortable and pleasant environment for transit passengers traversing the space or woiting for trains or buses.
The street level enterances to the concourse would be located at Benson Avenue, where the enterance would be in close proximity to the CTA Rapid Transit Station, at Maple Avenue, where the passageway under the CNW tracks would offer a direct access route; and at Church Street, along a concourse extension under the plaza level. Passengers arriving by taxi or being dropped off by private automobiles would enter the street level concourse on the Davis Street side. Bicycle storage facilities would be provided.
The balcony level concourse, which would be at the track elevation of CNW and CTA stations would not only facilitate transfers from CTA Rapid Transit trains to CNW southbound trains, but would, upon completion of the office building and Downtown II developments, provide ditect entrances to the Transportation Center from the sky-walk. Thus, it would serve to distribute the passenger flow to NORTRAN, CTA, and CNW boarding areas and platforms. Additional waiting areas and public facilities would be located on the balcony level, passengers would be able to observe the activity of the street level concourse and look across the plaza to the office building, the CNW station and
Downtown II beyond


Southbound passengers would be able to board CNW and CTA trains directly -from the balcony level waiting areas. Northbound passengers would use the Street Level Concourse and proceed, in the case of CNW passengers, through the existing underpass to the stairway werving the northbound CNW platform. Northbound CTA passengers would pass through the CTA street level fare collection facilities and would proceed to the two stairways serving the northbound CTA platform. Passenger elevators, serving all southbound and northbound platforms, would be provided for use by handicapped passengers.
The existing CTA station on Benson Ave. would be modified to permit passenger flow through the station into the Street Level Concourse. It is proposed that the existing underpass under the CTA tracks be widened to the overal1 width of the Concourse and that the new fare collection facilities be provided to serve CTA passengers. New stairways If adequate widths would be constructed and elevators would be installed. CTA passengers would find waiting areas on the Street Level Concourse and at the Balcony level.
The existing NORTRAN bus boarding area along the west curb of Benson Ave. would similarly be improved. A canopy would provide weather-protected pedestrian circulation from Davis Street to Church Street. The width of the boarding area would be more than doubled to accommodate enclosed waitng areas for NORTRAN and airport bus passengers and to increase circulation and queqing space. Another waitng area and rest room facility serving the bus passengers and dri-


vers would be available at the Street Level Concourse.
Waiting areas, ticketing and rest room -facilities to serve CNW passengers would be located at the west end of the Transportation Center Concourse. This location offers advantages in passenger convenience and comfort over continued use of the existing two story CNW Station. Balcony level ticket and waiting areas would accomodate Chicago-bound passengers, the predominant CNW passenger group, at the platform level. The southbound platform would also be reached by use of new, weather protected stairways at the Church and Davis St. viaduct. Similarly, the northbound platform would be weather accessible to CNW passengers by use of new, weathered protected stairways at these viaducts or by way of the pedestrian passage at the west, end of the Street Level
Concourse.


APPENDIX B


The -following are questions and their answers concerning the Depot -from an addendum to the competition program.
0)Are we to assume that the lower level o-f the depot stays as a restaurant, its current function, or are we free to propose a different use for the space?
A)The purpose of the competition is for the use of the entire train station, therefore, no current functions must be maintained.
Q)Is the south stairway within the existing depot required for vertical circulation to the CNW platform?
A) No.
Q)Is the elevator within the existing CNW train depot necessary to satisfy handicapped accessibility requirements for the CNW platform?
A) No.


APPENDIX C


STS Consultants Ltd.
Consulting Engineers
Report


STS Consultants Ltd.
111 Pfingsten Road
September 24, 1982
Northbrook, Illinois 60062 312-273-5440
Schal Associates, Inc.
33 W. Monroe Street Chicago, Illinois 60603
Attention: Mr. Larry Lantero STS Project No. 228 19
Reference: Preliminary Geotechnical Report for the Proposed Shand, Morahan &
Company, Inc. Building to be Located at the Northeast Corner of Church Street and Oak Avenue, in Evanston, Illinois
Gentlemen:
We have completed the preliminary subsurface exploration and related geotechnical engineering analysis for the above project as authorized by Schal Associates, Inc. on August 27, 1982. The enclosed report presents the results of our work and the recommendations which were developed subsequent to analysis of the results.
In summary, STS performed two soil borings (Boring B-l and B-2) and two hand auger probes (PR-1 and PR-2) at the approximate locations shown on the enclosed boring location diagram. The logs of the soil borings, along with the location diagram, are enclosed with this report. Also enclosed are general descriptions of our exploration and laboratory testing techniques, a detailed description of the site, soil, and ground water conditions, and preliminary analyses and recommendations concerning foundation design considerations for the proposed structure.
If there are any questions with regard to the information and recommendations contained in this report, or if we may be of further service to you, please do not hesitate to contact our office at any time.
Very truly yours,
Clyde N. baker, Jr., b.t.
Senior Principal Engineer
/ccb
end.
cc: Rittweger and Tokay, Inc. '
1580 N. Northwest Highway Park Ridge, Illinois 60068 Attn: Mr. William Rittweger
y 0 ' / J \AU^OuLyj& ( bsLCt/Sb''^
Michael G. Sibert, P.E.
Project Engineer
STS CONSULTANTS, LTD.
i.A f, A f / /
1


STS Consultants Ltd.
111 Pfingsten Road
Northbrook, Illinois60062 October I, 1982
312-273-5440
Mr. Larry Lantero Schal Associates, inc.
33 W. Monroe Street
Chicago, Illinois 60603 STS Project No. 22819
Reference: Recommendations Regarding Caisson Installation Procedures at the Proposed Shand, Morahan Company, Inc. Building to be Located at the Northeast Corner of Church Street and Oak Avenue in Evanston, Illinois
Dear Mr. Lantero:
We have reviewed the caisson installation procedure possibilities which were outlined in our report of September 24, 1982, and our comments are presented in this letter. The following caisson installation procedure, if properly done in the field, would also be acceptable.
It is our understanding that the caissons ere to be installed from approximately E!. -12'6" (job datum) in most areas of the new building. The caisson shaft can initially be drilled severe! feet below the level at which clay is encountered (expected to be on the order of between El.-IS' and -17'), and an upper temporary, oversized, steel surface casing set at that time to a depth of several feet below the clay in order to seal off the water-bearing granular deposits wnich are anticipated between El. -I2'6" and El. -I6'6".
Once the upper temporary steel casing has been installed, the caisson shaft can be driiled utilizing augers slightly larger than design sheft diameter to a depth of approximately 50 ft below general street level, the ievei from which our Boring B-i was performed, below the expected squeezing clay soiis, and an intermediate temporary casing installed to a depth required to get beneath the squeezing clay materials. The top of the intermediate liner should be above the bottom of the too casing. The intermediate casing should have a diameter slightly larger than design shaft diameter of the caissons so that after it is installed, drilling can be continued to the bearing depth utilizing auger flights of design shaft diameter. Belling operations can then be performed.
After the belling operations have been completed, the caissons should be filled as soon as possible with concrete up into the temporary intermediate casing, the intermediate liner jarred to free it from the outsiae soils, and the concreting continued upward to just below the bottom of the top casing.


Schal Associates, Inc. STS Project No. 22819 October I, 1982 Page 2
The intermediate casing can then be removed and a short section of permanent corrugated liner extending below the clay interface (expected to be encountered at about El. 16'6") installed. The permanent corrugated liner can then be filled with concrete to the caisson cutoff elevation.
After the caisson concreting has been completed, the space between the permanent corrugated liner and the temporary surface casing should be grouted and the temporary surface casing pulled to complete the caisson installation process.
To avoid the use of a full-length permanent corrugated metal liner, it is important that proper caisson installation procedures be followed to ensure the integrity of the caisson shaft with regard to potential squeezing of the soft clays encountered between depths of 25 ft"and 50 ft below general street level in our soil boring performed August 26, 1982, as well as from the granular, water-bearing soils encountered above El. -I6'6" (estimated). For the case of pulling casing, concrete should have a minimum 5-inch slump and should also have a retarder to provide some contingency against unanticipated delays resulting in pulling of the concrete locking in the casing before it can be pulled. In any case, it is recommended that the caisson contractor's installation procedure be reviewed thoroughly prior to acceptance. * * - - .........
If you have any questions with regard to the information in this letter, please contact our office at any time.
Very truly yours,
STS CONSULTANTS, LTD.
CjUyU ^
Clyde N. Baker, Jr., P.E. Senior Principal Engineer
/ccb


Client
Project
Preliminary Geotechnical Report
for the Proposed Shand, Morahan & Company, Inc. Building to be Located at the Northeast Corner of Church Street and Oak Avenue, in Evanston, Illinois
September 24, 1982 STS Project No. 228 19
STS Consultants Ltd.
I I I Pfingsten Road Northbrook, Illinois 60062


TABLE OF CONTENTS
Page
Project Overview I
Project Description I
STS Scope of Work I
Subsurface Exploration Procedures 3
Laboratory Testing Program 4
Analysis and Results 6
Site Conditions 6
Soil Conditions 7
Ground Water Observations 8
Recommendations
Design Considerations Foundations Basements Exterior Pavements Excavation Support Construction Considerations Dewatering Caisson Installation Additional Subsurface Exploration General Qualifications
10 10 10 I I 12 13 15
15
16 17 17
Appendix


PROJECT OVERVIEW
Project Description
It is our understanding that the proposed structure will be 12 stories in height with a single basement level. The site of the construction project is on the northeast corner of the intersection of Oak Avenue and Church Streets in Evanston, Illinois.
There is an existing, unoccupied, Wieboldt's department store at the site which is currently being demolished. It is our understanding that the existing footings, grade beams, and other obstructions within the new building footprint will be left in place at the end of the demolition program. Basement and sidewalk vault floor slabs in this area will be removed, however. \ ^
Tr ut e
The basement subgrade for the new structure will be at the same level as thct of the existing structure. In addition, some exterior pavement is also contemplated for the new structure for parking lot and roadway areas.
STS ScoDe of Work
To provide preliminary information in order to formulate design and construction plans, STS drilled one soil boring (B-l) to a depth of 91.5 ft below ground surface and another boring (B-2) to a depth of 13 ft below ground surface. After several attempts to move B-2 to a
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location which would provide accessibility to greater depths, the boring was abandoned when it encountered a metal object at a-depth of 13 ftr- This metal object was thought to be possibly a large electrical duct, and it was considered unsafe to attempt to penetrate it further--------
In addition to the soil borings described above, STS drilled two hand auger probes in the embankment between the existing building and the railroad tracks on the northeast side to depths of 6.5 ft in order to determine the character of the fill in the berm area. The locations of the soil borings and hand auger probes are indicated on the enclosed boring location diagram.
A laboratory testing program was also performed in order to further characterize the soil samples recovered from Borings B-I and B-2. The results of the laboratory testing program are indicated on the respective boring logs.
Recommendations contained in this report are based upon the data obtained from the soil borings and laboratory analysis. The purpose of this report is to describe the site, soil, and ground water conditions encountered in the borings, to analyze and evaluate the test data obtained with respect to the proposed construction program, and to submit recommendations regarding-design and foundation, basement, floor slab, and exterior pavement design considerations.
STS Consultants, Ltd.


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Subsurface Exploration Procedures
Soil borings B-l and B-2 on this project was performed with a truck-mounted rotary drilling rig which utilized various cutting bits and drilling fluid to advance the bore holes. Additionally, steel casing was required in the upper soil strata to maintain open bore holes. Upon the completion of Boring B-l, the bore hole was grouted with cement grout to preclude future problems occurring from water coming up the bore hole into the caisson shaft.
Representative soil samples were obtained by means of the split-barrel and shelby tube sampling procedures, in general conformance with ASTM Specifications D-1586 and D-1587, respectively (see Appendix). In the split-barrel sampling procedure, a 2 inch O.D., split-barrel sampler is driven into the soil a distance of 18 inches by means of a 140 pound hammer falling 30 inches. The Standard Penetration Resistance Value is the number of blows per foot of penetration for the final 12 inches of driving. This value can be used to provide a qualitative indication of the in-place relative density of cohesionless soils. The indication is qualitative only, since many factors can significantly affect the Standard Penetration Resistance Value and prevent direct correlation of results obtained by drill crews using different drill rigs, drilling procedures, and hammer-rod-spoon assemblies.
In the shelby tube sampling procedure, a thin-walled, steel, seamless tube with a sharp cutting edge is pushed hydraulically into the soil and a relatively undisturbed sample is obtained. Further laboratory testing performed on the undisturbed soil sample CGn provide an indication of its dry density and unconfined compressive strength.
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Hand auger probes PR-1 and PR-2 were performed by a two-person hand auger crew which advanced the probe utilizing a sledge hammer. The probes were advanced in this manner to depths of 6.5 ft.
Field logs of the soils encountered in the soil borings were maintained by the drill crew. All soil samples obtained from the drilling operations were sealed immediately in the field and brought to our laboratory in Northbrook, Illinois for further examination and'testing. The drill crew maintained regular contact with the office engineering personnel so that proper evaluation of the soil conditions and appropriate drilling procedures could be maintained throughout the field exploration program.
Laboratory Testing Program
The laboratory testing program consisted of performing water content tests on all soil samples obtained from the drilling operations. In addition, hand penetrometer tests were performed on representative portions of the cohesive soils recovered in the shelby tube and split-barrel samplers. In the hand penetrometer test, the unconfined compressive strength of a cohesive soil is estimated, to a maximum value of 7 tons per sguare foot (tsf), by measuring the resistance of the soil sample to penetration by a small, spring-calibrated plunger.
In addition to the water content and hand penetrometer tests, several dry density and unconfined compression tests were performed. In the unconfined compression test, the soil sample is axially loaded at a slow, constant strain rate until failure occurs. The unconfined
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compressive strength is defined as the maximum stress at failure, but not greater-than the stress at 20% strain. The results.of all tests performed in the laboratory are indicated on the enclosed boring logs.
In conjunction with the laboratory testing program, an experienced soil engineer classified each soil sample on the basis of texture and plasticity in accordance with the Unified Soil Classification System. The estimated group symbol according to this classification system is shown in parentheses following the soil descriptions on the boring logs. A brief explanation of the Unified System is included with this report. A soil engineer grouped the various soil types into the major zones noted on the boring logs. The stratification lines indicated on the logs are, in some cases, estimated; in-situ, the transition between soil types may be gradual.
Additional comments with regard to the preparation of final boring logs from the field logs and laboratory Test data are described on the sheet entitled: "Procedures Regarding Field Logs, Laboratory Data Sheets and Samples", which is included with this report.
Soil samples recovered in the borings will be retained at our Northbrook facility for a period of 60 days, after which they will be discarded unless other instructions as to their disposit ion are received.
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ANALYSIS AND RESULTS
Site Conditions
At the time of the exploration, the existing Wieboldt's store was in the early stages of the
demolition process. The locations of Borings B-l and B-2 were selected based on their accessibility and, since one of the borings did not penetrate to its desired depth, it is recommended in this report that more borings be performed after the site has been demolished and cleared, and prior to commencing caisson installation.
It is noted that there are existing Chicago and Northwestern railroad tracks which run by the site along the northeast side and are located atop a berm at approximate elevation +40 ECD (Evanston City Datum, as extrapolated from the survey prepared by B.H. Suhr and Company on August 9, 1982). General ground surface at the site is approximately +25 ECD. At its closest point, the wall of the proposed structure is approximately 25 ft from the top edge of the railway embankment. The top of the basement slab in the existing structure is at approximately +1 1.5 ECD.
No survey measurements were performed to determine the ground surface elevation at the boring locations. It is estimated, however, that they were at an elevation of approximately *24.5 ECD, which coincides with the elevation of the first floor slab of the existing structure, as shown on the available drawings.
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Soil Conditions
The specific soil conditions encountered in the borings are indicated on the enclosed boring logs. Briefly, however, Boring B-l encountered a concrete wall extending from the ground surface to a depth of 18-ft. Boring B-2 encountered a concrete floor slab which extended to 2 ft in depth, and which-was underlain to boring termination (13 ft) by loose to very loose sand which became saturated at 3.5 ft.
In Boring B-l, gray, very stiff, silty clay was encountered immediately beneath the bottom of the concrete wall at a depth of 18 ft. This material extended to a depth of 24 ft at which point a 1.5 ft-layer of saturated silt was observed. Beneath the saturated silt, and beginning at a depth fo 25.5 ft {-1.0 ECD), gray, soft to medium, silty clay with a water content near 30% and an unconfined compressive strength of around 0.5 tons per square foot (tsf) was encountered which extended to a depth of 54 ft below ground surface. From a depth of 54 to 70 ftt.4he silty clay became medium to stiff in consistency and the water content decreased somewhat to approximately 20%.
At a depth of 70 ft below ground surface, hard, gray, sandy clay (hardpan) was encountered. The hardpan materiaTpossessed water content values close to 10%, dry densities of over 130 pounds per cubic foot (pcf), and unconfined compressive strengths of over 6.5 tsf. The hardpan material contained numerous boulders and/or obstructions as noted on the boring log. The hardpan extended to a depth of 91 ft, at which point extremely dense, gray, gravelly, fine to coarse sand was encountered and Boring B-l was terminated at 91.5 ft.
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Hand auger probes PR-1 and PR-2 were performed on the existing railroad embankment in order to characterize the nature of the embankment soils. Both of the probes encountered brown, silty sand fill -to total depths-of 6.5 ft.---- >; -; -- -? e-; _
Ground Water Observations -. - - ..
Ground water observations were made prior to casing removal in Boring B-l. At that time, a water level at 13 ft below grade was noted.
In addition, STS Senior Principal Engineer, Mr. Clyde Baker, visited the site on August 6, 1982 in order to observe the-basement conditions in the existing Wieboldt's store, paying particular attention to water seepage. At that time, the existing drainage system had been shut down for several weeks and the intent of the site visit was to see what level the water had risen to in the basement with the drainage system shut down. At the time of the site visit, there was very, little .water seepage apparent in the basement which had a floor slab approximately 13 to 14 ft below the first floor level. It was noted in the north end of the building, where the depressed mechanical room area was approximately 4 ft below the surrounding basement slab, that there appeared to be about 1.5 ft of water in the depressed area. It is our understanding that subsequently water was periodically pumped out of the mechanical room area and each time it would gradually seep back, rising serveral inches per day.
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Since the existing basement walls extend close to or into the underlying clay (as evidenced by the depth of concrete noted in Boring B-l), they are probably cutting off much of the lateral water seepage into the basement area, and the observed seepage is coming through the limited zone of permeable sand that may exist beneath the walls at some locations.
It was noted in prior explorations in the vicinity of this site that the near-surface granular soils extended to a depth of approximately 13 to 14 ft below grade at those boring locations. The soil in Boring B-2 was saturated below a depth of 7 ft, indicating that the current water table is located approximately at elevation +17.
Fluctations in the location of the long-term hydrostatic water level are normal and may occur throughout the years, depending upon variations in precipitation, evaporation, surface runoff, and future developments in and around the site area.
ST3 Consultants. Lid.


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RECOMMENDATIONS
Design Considerations Foundations
Based upon available soil and structural information, we recommend that drilled pier foundations (caissons) be used to support the proposed structure. These caissons should be located on or in the hardpan materials which were encountered at a depth of approximately 70 ft below ground surface (-44.5 ECD). For caissons which are installed on or in the hardpan at a depth of approximately 70 to 75 ft, a maximum net allowable soil bearing pressure of 25,000 pounds per square feet (psf) should be utilized for caisson design purposes. The maximum net allowable soil bearing pressure refers to that pressure which may be transmitted to the foundation sub-soil in excess of the final minimum surrounding overburden pressure.
No major problems are anticipated in constructing the bells for the caissons since they would be constructed in either hard clay (hardpan) or in the medium to stiff clay just above the hardpan. Care should be exercised not to extend the caissons below a deDth of approximately 85 ft in order not to come too close to the underlying saturated granular soils, which could result in inundation of the caisson shaft if the water in the granular deposits below this depth is water under artesian pressure.
STS Consultants, Ltd.


STS Project No. 22819
September 24, 1982
Basements
The walls of the proposed structure basement should be considered unyielding and, as such, designed to withstand lateral earth pressures in accordance with an equivalent fluid pressure of at least 50 psf per foot depth of wall above the ground water table, and at least 85 psf per foot depth of wall below the ground water table. This value is based upon an assumed unit field weight of 125 pcf, an earth pressure coefficient of 0.4, and the use of granular backfill material adjacent to the wall. In addition to the lateral earth pressures, an allowance for surcharge loads in the zone adjacent to the basement wall having a slope of I vertical to I horizontal away from the base of the wall should be made.
In addition to the lateral earth pressures noted above, the basement should be waterproofed up to the maximum .-anticipated water table level, and dampproofed above that level. The basement slab should be underlain by an adquate underdrainage system. In this system, a minimum of 6 inches of free-draining granular underslab material should be placed immediately beneath the basement floor slab and lateral underslab drains on 50 ft (maximum) centers and around the building perimeter should be provided. These drain lines may be comprised of 6-inch diameter perforated or porous wall closed joint pipe and they should each be surrounded by a minimum of 6 inches of well-graded filter material compatable with the openings in the drain lines. The underdrain system should be interconnected and should discharge into either l)a sump pit and pump, or 2) to a lower elevation storm sewer or other discharge point.
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If fill is required to attain final grade between the excavation and the exterior basement walls, the backfill should be inorganic, free of debris, and non-frost susceptible. It should be placed in lifts not exceeding 9 inches in loose thickness and compacted to a minimum of 90% of the maximum density obtained in accordance with ASTM Specification D- 1557, Modified Proctor Method. The upper 2 ft of this layer should consist of cohesive backfill material which should act as a: cap to .minimize infiltration of surface water into the granular material below, and thus relieve excess seepage into the basement underdrain systems. Also, the ground surface adjacent to the basement walls should be sloped downward away from the wall somewhat in order to aid in draining surface water away from the structure.
Exterior Pavements
For the design and -construction of any exterior pavements on the project site, we recommend removal of any unsuitable surface fill materials to a depth of at least 2 ft below design pavement subgrade. After removal of these materials and in preparation of the pavement placement, we recommend that the area be observed by an experienced soil engineer in order to aid in locating any unsuitable materials which should then be removed and replaced. ---------
The location of unsuitable pavement subgrade materials may be detected by using a proofrolling procedure in which a heavily loaded, tandem axle dump truck of at least 25 tons gross weight (or equivalent) is driven across the area under the observation of a soil engineer. All areas which display noticeable deflection or spongy action beneath the proofrolling vehicle should be removed and replaced accordingly.
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September 24, 1982
Where new fill materials are required to reach the design subgrade elevation of the exterior pavements, we recommend that the materials be inorganic, free of debris, and non-frost susceptible. The materials should be placed in lifts not exceeding.9 inches in loose thickness and compacted to a minimum of 90% of the maximum density obtained in accordance with ASTM Specification D-1557, Modified Proctor Method. Ninety-five percent compaction should be achieved, beneath any pavements which will be subjected to frequent heavy truck traffic or other heavy loads.
We also recommend that "project pavements be provided with facilities for'surface and subsurface drainage. Where standing water develops, either on the pavement subgrade or within the base course layer, softening of the subgrade or other problems resulting in pavement deterioration should be expected. We would be pleased to be of further service to you in providing additional recommendations regarding design of the project pavements if furnished with information regarding loading, usage, and frequency of load application.
Excavation Support -------
In most areas of the site, the existing basement walls are deep enough to extend into the clay which underlies the near-surface granular soils and forms an effective water cutoff barrier. In areas where the walls do not extend deep enough, steel sheeting should be driven into the clay to effect this Durpose. If a continuous cutoff is made by the existing walls and necessary steel sheeting, we do not expect major construction problems due to ground water infiltration to occur. Any seepage which dees occur due to ground or surface water accumulation may be removed by standard sump pit and pump procedures.
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Once the existing structure is demolished, the existing basement walls which are left in place will have to be braced to withstand outside earth pressures. In areas where there is sufficient room, a temporary earth-rubble berm may be constructed in order to protect the exposed basement foundation walls. The lateral room required for this berm, if it is constructed of rubble (with an angle of repost of approximately 45) is at least 13 to 14 ft (assuming that approximately 13 to 14 ft of wall height will be exposed). This will be the primary form of temporary wall support along the western side of the existing foundation, and the construction of the rubble berm in this area should be done in sections, one bay spacing at a time, in order to avoid leaving the foundation wall unsupported for an excessive length of time.
In the section of the existing foundation wall which parallels the railroad tracks, it is our understanding that fill will be placed up to design first floor elevation of +24.58 ECD to support the wall below this level. Since it has been established that the support of the train trccks is not a factor (i.e. an approximate slope of ^L5 H:Tv)can be maintained between the railroad tracks at +39.98 ECD and the existing first floor level at +24.58 ECD), the retaining wall bracing above an elevation of +24.58 ECD need only be designed taking into consideration soil pressures from the embankment soils on the railroad side of the retaining wall. We recommend that lateral earth pressures of at least 50 psf per foot depth of wall above the water table and at least 85 psf per foot depth of wall below the water table be used in designing this retaining wall support system.
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We also recommend that the permanent earth berm which is used to retain the wall above +24.58 ECD be kept at a maximum slope of^2H: lV)to provide long-term stability. In areas where this slope is not feasible, a supplementary strut retaining system should be implemented. If the fill below +24.58 ECD is to be used to support any supplementary retaining wail footings, a maximum net allowable bearing pressure of the fill of 1500 psf should be utilized.
If the 2H:IV slope is too steep to prevent erosion (and subsequent less of vegetation), then we suggest that a geotextile be placed over it which will stabilize the slope while still allowing vegetative growth.
Construction Considerations
Dewatering
As mentioned previously, we do not anticipate any major problems due to ground or surface water accumulation during the course of the construction project if there is a continuous cutoff made around the building perimeter into the clay which underlies the near-surface fill soils. This cutoff can be effected by a combination of existing basement walls which extend into the clay and steel sheeting in those areas where the walls do not extend that deep. If an effective cutoff is made, any temporary accumulations of water may be removed by employing standard sump pit and pump procedures.
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It should be noted that excavations dug in the spring or early summer may incur larger amounts of seepage and/or trapped water conditions than would the same excavations dug in the fall.
Caisson Installation
It will be necessary to utilize an oversize diameter temporary steel casing which will extend through the upper rubble and water bearing granular soils and into the underlying clay which we expect will be encountered at a depth of approximately 13 to 14 ft. The caisson shaft may then be drilled to the design bearing elevation through this upper casing. The existing basement slab should be demolished to facilitate caisson installation, however, a layer at -teast 2 ft thick of rubble should be left in the basement area to provide a working platform.'-'-for the caisson installation equipment.
Since the clay soils which were encountered above a depth of approximately 54 ft had relatively low strengths and high water contents, a potential for squeezing exists if the caisson holes are left open for extended periods of time. For this reason, it may be necessary to either extend the temporary surface casing through the softer layers to a depth of at least 50 ft or to use a temporary intermediate ccsing and then to use a permanent corrugated metal liner of design shaft diameter extended to at least I ft below the temporary casing. After concreting the inside of the liner, the annular space between the liner and the temporary casing should be grouted and the temporary casing pulled.
^ S.'s L-rf's/.
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In any case, a temporary casing should be used for protection whenever any personnel are in the caisson shaft or bell.
Caissons should be excavated and concreted the same day in order to minimize possible seepage problems and cave-in of the lower shaft and bell. Care should be exercised to remove loosened materia! at the base of the caisson bells before they are concreted.
Additional Subsurface Exploration
After the demolition program has been completed, we recommend that several additional shallow soil borings or test pits be performed within the proposed building area in order to determine I) the depth at which the clay which underlies the near surface fill and granular soils is encountered in the perimeter wall areas, and 2) a more precise definition of the upper ground water table. We also recommend one additional deep boring to provide confirming information on and the depth at which hardpan is encountered, and the thickness of the hardpan deposit. _ _
General Qualifications
This report has been prepared in order to aid in the evaluation of this property and to assist the architect and/or enqineer in the design of this project. The scope is limited to the specific project and location described herein, and our description of the project represents our understanding of the significant aspects relevant to soil and foundation characteristics.
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In the event that any changes in the design or location of the building (si as outlined in this report are planned, we should be informed so the changes can be reviewed and the conclusions of this report modified or approved in writing by the soil and foundation engineer.
It is recommended that all construction operations dealing with earthwork and foundations be reviewed by an experienced soil engineer to provide information on which to base a decision whether the design requirements are fulfilled in the actual construction. If you wish, we would welcome the opportunity to provide field construction services for you during construction.
The analysis and recommendations submitted in this report are based upon the data obtained from the soil borings performed at the locations indicated on the location diagram and from any other information discussed in this report. This report does not reflect any variations which may occur between these borings. In the performance of subsurface explorations, specific information is obtained at specific locations at specific times. However, it is a well-known fact that variations in soil and rock conditions exist on most sites between boring locations and also such situations as ground water levels vary from time to time. The nature and extent of variations may not become evident until the course of construction. If variations then appear evident, it will be necessary for a re-evaluation of the recommendations of this report after performing on-site observations during the construction period and noting the characteristics of any variations.
ST3 Consultants. Ltd.


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Because of the possibility of these unanticipated subsurface conditions occurring, we recommend that a "changed condition" clause be provided in the contract both with the general contractor and in contracts with sub-contractors involved in the foundation and earthwork construction. It is felt that the inclusion of this clause will permit contractors to give lower prices because they will not need to provide as much in contingencies as they normally would if equitable adjustment of changed conditions will minimize conflicts and litigation with the attendant delays and costs. Furthermore, by the immediate recognition and adjustment in contract price at the time any changed conditions are encountered, the immense problem of trying to recreate facts when litigation develops later is eliminated. A mediation/arbitration procedure is recommended in the event that the owner, contractor and professionals do not agree on the changed conditions at the moment they are disclosed. If you wish, we would be pleased to furnish additional information pertaining to this procedure. A suggested wording for a change condition is given in the Appendix.
STS Consultants. Ltd.


APPENDIX
Standard Clause for Unanticipated Subsurface Conditions
Location Diagram
General Notes
Procedures Regarding Field Logs, Laboratory Data Sheets and Samples
Boring Logs
ASTM Specifications
D-1586-67 D-1587-67
Unified Soil Classification System


Standard Clause for Unanticipated Subsurface Conditions
"The owner has had a subsurface investigation performed by a foundation consultant, the resuits of which are contained in the consultant's report. The consultant's report presents his conclusions on the subsurface conditions based on his interpretation of the data obtained in the investigation. The contractor acknowledges that he has reviewed the consultant's report and any addenda thereto, and that his bid for earthwork operations is based on the subsurface conditions, as described in that report. It is recognized that a subsurface investigation may not disclose all conditions as they actually exist and further, conditions may change, particularly groundwater conditions, between the time of a subsurface investigation and the time of earthwork operations. In recognition of these facts, this clause is entered in the contract to provide a means of equitable additional compensation for the contractor if adverse unanticipated conditions are encountered and to provide a means of rebate to the owner if the conditions are more favorable than anticipated.
At any time during earthwork, paving and foundation construction operations that the contractor encounters conditions that are different than those anticipated by the foundation consultant's report, he shall immediately (within 24 hours) bring this fact to the owner's attention. If the owner's representative cn the construction site observes subsurface conditions which are different than those anticipated by the foundation consultant's report, he shall immediately (within 24 hours) bring this fact to the contractor's attention. Once a fact of unanticipated conditions has been brought to the attention of either the owner or the contractor, and the consultant has concurred, immediate negotiations will be undertaken between the owner and the contractor to arrive at a change in contract price for additional work cr reduction in work because of the unanticipated ccnciticns. The contractor agrees that the following unit prices would appiy for additional cr reduced work under the contract. For changed conditions for which unit prices are net provided, the additional work shall be paid for cn a time and material basis.'1
Another example of a changed conditions clause can be found in paper No. '+025 by Robert F. Borg published in A5CE Construction Division Journal, No. CC2. September 1964, page 37.
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STS Consultant*