# 1L_ L/UUIUI V
by charles a. donley
environmental design auraria library
DEVELOPMENT GUIDE FOR PLANNERS
Presented to the Faculty of the Division of
Planning and Community Development
College of Design and Planning University of Colorado at Denver
A thesis prepared in partial fullfillment of the requirements for
Planning and Community Development
By: Charles A. Dehley December 19o4
Professor Michael Pharo Professor Herbert Smith
LAND DEVELOPMENT GUIDE FOR PLANNERS
Thesis Prof. Daniel Schler
Planning/Community Development Fall 1984
University of Colorado at Denver
Table of Contents
Problem Statement...................................... 6
Street Plan and Profile
Sewer Plan and Profile
Water Plan and Profile
Gas Electric and Telephone
Classification Compaction and Testing Problem Areas
Overlot Grading Sanitary Sewer and Water Curb and Gutter Drainage Facilities Gas and Electric Base and Paving
Site Plan Grading Plan
Street Plan and Profile Water/Sewer Plan and Profile Cost Estimates Sample Schedule
This document describes the land development^" process. It is written because there is no standardized text for planners which describes the process or the reasoning behind it. Out of frustration for gaining insights into this process, the author made the necessary sacrafices to gain employment in land development and learn about the subject. This thesis will demonstrate the relevancy of land development for planners and then describe the residential land development process in as succinct and generic method as possible.
The land development process is usually taught in construction management courses. The written material describing this proces is rarely presented in a clear and concise manner and the entire process is not described as a whole. The description in this paper is a distillation of experiences gained in the field and insights provided by local experts.
Land development is the process of taking raw ground and preparing it to be built upon. The process includes overlot grading and construction of sewer, water, gas, electric, telephone and drainage improvements as well as streets. Development is the overall process which incorporates building construction and land development.
This paper assumes that the reader understands the principles of site planning. A knowledge of topographic maps, land use types, environmental constraints and the zoning approval process are prerequisites of understanding the description that will follow. It is the goal of this paper to present the fundamentals of land development in a manner which is comprehensible to the average planning student.
In many respects it is a supplement to Lynch's Site Planning" chapters 4,7,8 and 13. However, the paper seeks to be less theoretical and more oriented toward the methods whereby land development projects are completed. Practical problems are presented which are not addressed by Lynch or by other authors. Ideally, this paper would be read concurrently with Lynch (references are included to facilitate this process).
Land development and its related sciences are tremendously complex. Each project brings with it a variety of new challenges and to attempt to cover even the most common variations would be impossible. However, the fundamentals are presented; it becomes the responsibility of the individual to apply the information or complete further research and then extrapolate the principles into appropriate decisions.
Lynch, Kevin. Site Planning. MIT Press: Cambridge, Mass. 1979-
The author's experiences and primary resources are from Colorado Springs, so the paper tends to reflect local practices, and conditions. Every attempt has been made to eliminate these assumptions, however they are frequently unavoidable if one is to establish a standardized methodology.
The writer does not seek to make judgements about the efficiency of the process, or its impact upon the environment. Minimizing environmental impacts or better yet utilizing those impacts to enhance the environment should be the goal of every developer. This paper does not seek to detail the potential mitigation measures and/or evaluate their efficacy. However, by better understanding what land developers seek to do, we as planners will be better prepared to offer reasonable solutions.
This paper has five major sections. The first four describe the primary peripheral subareas of land development which includes, engineering, soils, surveying and the heavy equipment which does the work. The final section describes the process itself. The appendix illustrates a site plan, a grading plan, street plans and sewer/water plans for an imaginary project. In addition a schedule and a cost estimate has been prepared as well as certain standard specifications for City of Colorado Springs.
Land development is an important subject for planners. Most of the roles planners assume, involve to some extent land development, yet most planners treat it as a mysterious unknown process which does not affect them. Land development represents a vital body of knowledge which planners must understand if they are to act effectively, however there is no resource written for planners which describes land development. This thesis is written as a solution to that problem. It is a guide for planners which describes the land development process.
Land development occurs after site planning, land use and zoning issues have been resolved. Subdivision or platting is intwined with land development and is in many respects the first step in the process. Thus, land development occurs during and immediately after current planners finish their official tasks, yet few planners have a perspective on the overall process. Hopefully, the principles inherent in land development have been incorporated in the site plan (probably via the developer's consultant). However, planners can not begin to evaluate these issues effectively without a rudimentary understanding of land development.
Most of the goals and objectives of the comprehensive plan are implemented during land development. Likewise zoning decisions
come to life during this period. The successes and failures in the implementation of each objective become evident after the community begins to use the improvement. However, the development of the project is when the design is implemented and with it the goals of the community. Land development is a critical step for goal oriented planners.
Planners are specialists in generalism. They must combine the arts and sciences which affect a community's growth into a coherent recommendation. Among the careers a planner must embrace are architecture, market analysis, law, environmental analysis and sociology. Yet for all of their varied knowledge a gap of expertise exists for most planners between the moment of council/commissioner approval and the issuance of a certificate of occupancy; between theoretical density impacts and the moment an individual impacts a community's systems. Land development is the embodiment of that transition.
An important goal for planners is the ability to communicate successfully with the practitioners in the field. Those involved in land development have their own lexicon whether referring to surveyors as engineers or to a 623 as an elevating scraper. Understanding the nuances of that language takes time, but without that knowledge one can not hope to work with those in the field (it also helps to drink lots of beer after work and chew).
There is also the intangible benefit of placing oneself in perspective with the larger effort. To understand what is going on when viewing a project under construction. A certain satisfaction comes from knowing what is happening and how one influenced the finished product.
More importantly, by understanding what is happening, a more refined judgement may be obtained as to what is good and bad design, as well as gaining insights into how to achieve better development. A planner should have a different outlook on the world, wherever he goes. A drive to the store becomes a lesson in planning. The development process is at the core of this way of thinking and the description below becomes a primer to the land development portion of that process.
Planners often act in a variety of roles. Each requires certain qualifications, but most of these roles relate to the built environment and thus to land development. The following is a list of roles commonly assumed by planners with a brief discussion of land development's relevancy to them.
For city planners whose responsibilities revolve around zoning and subdivision, land development is the implementation of their recommendation. In order to assess developer demands and propose viable solutions to certain issues, a planner must understand land development. This is especially important in
reviewing development plans for PUDs since additional design control is imparted to planners in this type of approval.
The city planner who is involved in long range planning may need to evaluate various projects with regard to cost, feasibility and community benefit. This skill is particularly important in capital improvement programming where various projects must be prioritized and then implemented in appropriate order. For example a street widening may require a bridge to be widened first followed by heavy expenditures for correcting drainage problems or moving utilities. Without an understanding of land development principles, a planner may not be able to assess their impacts, let alone identify these problems in the first place.
The small town planner may find himself responsible for more than the traditional tasks of comprehensive planning and zoning. Tasks which normally would be assigned to an engineer, may be left to a planner. Among these tasks are; evaluating subdivision cost estimates, local control of land development activities or even responsibility for supervision of infrastructure improvements. Without a strong understanding of land development, the planner will be unable to communicate with the principal actors in the process let alone direct or control their activities.
One of the environmental planner's primary sources of air and water pollution non-attainment is construction. Particulate
levels are usually directly related to land development activities as are problems with erosion and site hazards. Environmental planners must understand the land development process if they hope to control these problems.
For the land planner t the land development process represents a vital segment of knowledge. Most of the principles required for effective site planning are reflected in land development. A site plan comes to life as the land development is constructed, with only the buildings and landscaping left to make it complete. To achieve a workable design he must understand the principles embodied in land development. These include engineering, urban design and landscape architecture. As a consultant to the developer he must also incorporate the generalized cost impacts with the design factors to create a feasible and acceptable plan.
The developer is remarkably like the planner in that he must coordinate the same group of disparate disciplines toward a single goal. The developer adds a couple other responsibilities (finance and sales) and one important variable, risk. However, planners are better adapted to become developers than the characters who usually undertake land development (whether they are real estate brokers, businessmen or building materials distributors) The point is, planners are well adapted to be
-'Daniel Schler. The Private Land Developer: A Sociological Interpretation. PhD Thesis. University of Missouri, August 1966.
developers but they rarely make the transition partly because they rarely understand the process after the subdivision plat is recorded.
Most planners will not become developers, however that does not minimize the importance of understanding land development. It is vital that an individual understand how his input fits into the final product. This is even more important to planners since they seek to manipulate the built environment for the good of the community. Unless a planner understands the process whereby his inputs are utilized, he can not hope to achieve his desired results.
This thesis began as an independent study in the Spring of 1982. The author wanted a broader understanding of the development process and especially that portion which immediately followed his inputs as a planner. However, he was frustrated in his efforts to find resources that described the process, its costs, its actors and its scheduling. So, he left his job as a planner and obtained work as a land development field foreman. Thus, this thesis is based upon participatory learning.
My primary responsibility as a field foreman was direction of the various subcontractors constructing the land development improvements. I acted as liaison between the Vice President of
North American Homes and the foreman in the field who actually directed the work crews. IJoodstone, a 112 acre residential project in northwest Colorado Springs was my primary responsibility, however I handled portions of several smaller proj ects.
The job description of field foreman is included in the appendix^. Some of the specific tasks performed included; preparing preliminary budgets, estimating quantities of materials from plans, obtaining subcontractors bids, applications for permits, coordination of subcontractors on-site, homeowner liaison, direction of site labor and on-site design adjustments. The days usually lasted ten hours, plus at least half of Saturday on weekends.
Throughout my tenure I constantly asked questions about why and how things were done. This was facilitated by a manager who was willing to take the time needed to accept my judgement or explain why not. As a follow-up, this text has been reviewed by some of the experts, working in the field and it has been corrected as needed.
Now that I understand this process better, I could direct a planner who wanted to learn about land development on how to
achieve that end. That methodology would include studies of engineering texts, cost estimate handbooks and perhaps a course in construction management. However, I do not believe that that student would learn as quickly or thoroughly as they would in the field nor that any document exists which consolidates that information for planners. Here it is on silver a platter, enj oy.
Consultants represent a resource of information which is hired for advise on particular segments of the process. They include; civil engineers, soils engineers, surveyors and construction managers. Civil engineers design the various segments of a project using the advise of a soils engineer to specify certain criteria or materials where soil conditions warrant. The civil engineer occasionally inspects the actual construction process when governmental inspectors are not used. Surveyors are frequently an arm of the civil engineer and they are responsible for establishing the appropriate location for construction to occur. A new trend in land development is the use of construction managers who specialize in coordinating the entire process.^
Mr. Michael Mallon, Mallon Development, 10/84.
The subdivision process, as dictated by SB 35, is usually the first step that requires direct involvement by an engineer. The process legally divides the project into individual lots and seeks to guarantee the developer will complete the infrastructure necessary for habitation (eg. streets and utilities).
The process includes a preliminary and final plat approval. The preliminary plat allows review of the overall development with primary emphasis on required infrastructure improvements (esp. street alignments, street widths and drainage). The approval is usually not completely binding on the applicant so it allows the opportunity receive local review without committing to a final layout or to the engineering necessary to be confident of a final design.
IJhereas the preliminary plat is for the entire development, the final plat is usually phased. The final plat is recorded by the county, and as such is the legal document for establishing each lot and its boundaries. Cost estimates are prepared for all of the land development improvements. As a means of guaranteeing the improvements will be completed, a letter of credit or other security is required from the developer. This money is released upon acceptance of the constructed streets and utilities by the municipality. All of the design submittals listed below except the grading plan require final plat approval first.
The grading plan takes the site plan and molds it into the shape of the land. The plan shows the dirt contractor where to take dirt from (cuts or excavation) and then where to place that dirt (fills or embankment). A topographic map of the project is overlaid with contours of the finished ground form. Usually the contours are differentiated from original topography by using straight lines and/or different line weights.
Certain assumptions must be established before the grading plan can be drawn. Among these are; the sewer flowline (which streets and which direction), anticipated drainage flows, and minimum curves for streets (see street plans). The site plan should indicate unit types, building locations, and the way the project should be integrated, which will indicate grades around the buildings (eg. walkout basements).
Starting with the streets, the proposed grades are drawn. Unit locations are established, together with their front and rear yards. Flexibility is usually available in street and rear lot grades, so that integration is achievable. Surface drainage facilities as per the drainage plan are integrated into the plan.
Minimum grades on lawns is 1% with 2% being preferred.Special attention must be paid to minimizing steep slopes. These are usually described in a ratio, with 3:1 being the maximum on sandy soils and 2:1 the maximum on clays. These are not
absolutes but represent a continuum of realistic values. For example; if clays are thoroughly compacted, seeded, matted and a berm is built across the top of the slope, a 1:8 to 1 may achieved^. The second option on steep slopes is to use a retaining wall which may be made of concrete, gabions (wire baskets filled with rock) or wood timbers. Assuming proper construction and design these range from highest to lowest in cost, height/slope potential, and durability.
Another concern is assuring that neighboring site's ground is not be changed and that drainage volumes and patterns will not be adversely affected. Grades at the property lines may not be changed, so elevations changes are transitioned to zero. This may require steep slopes or retaining walls, however these steps should be avoided if possible. Existing drainage patterns must be preserved which may result in detention or retention ponds, and cutoff drains or swales.
The magic of creating a grading plan is in balancing the cuts and fills. It is 2 to 3 times more expensive to import or export soil from off site sources, so the goal becomes to make the site self sufficient dirt wise. By adjusting depths of cuts and fills, the site can usually be made to balance, however a series of unknowns come into play. It is difficult to determine
^Mr. Raymond Childs, Monks Construction, 10/84.
confidently the volumes of cuts and fills. Also the amount of shrinkage that fill soils will experience is highly variable.
Lynch^ discusses the primary methods of measuring cut and fill volumes. However, none of the currently used methods is completely accurate because small variations in elevation can translate into significant volume differences and soil shrinkage is rarely predicable. Usually, a computer is used, with a grid of points and their elevations being analyzed together. The more points, the greater the accuracy.
Soil shrinkage is dependent upon the level of compaction
achieved, the moisture content, how much the soil is fluffed-up
and the type of soils involved. The soils engineer should be
able to provide a rough estimate of shrinkage. Fluffy, dry
clays can shrink 55%, dry sands average 30% and wet sands have
almost zero shrinkage However, unknowns will remain such as when a contractor makes a few too many passes with a compactor or the specification for compaction is slightly high. Soil engineering is an inexact science, and as such unknowns will frequently exist.
^Lynch, Site Planning, p.163-168.
Mr. Raymond Childs, Monks Construction, 10/84.
Street plans and profiles are prepared in conjunction with the
grading plan. Two critical issues must be assured, adequate
sight distance and drainage. Streets grades should not exceed
6% on arterials, 10% on other streets and 4% at intersections.
Sight distance is a function of the vertical and horizontal
curves discussed by Lynch These curves also provide smooth transitions between grade and directional changes. Their radii is specified based upon the traffic expected upon them.
Drainage is determined by the side slope of the street (usually crowned), the gutters and drainage structures (usually called inlets or basins). Streets generally have 2% slopes from the crown or center to the gutters and at least .5% (1% preferred) longitudinally, for adequate drainage.
The street crossection, the depths of its materials, is a function of the traffic projected upon it (both type and volume) and the soils upon which it is built. A HVeem soil test is performed which determines the soil's potential for shifting under a load. Clays are plastic by nature and thus less stable so greater depths of stabilizing materials are required.
Included with the street crossection in the appendix is a schematic utility location plan. These facilities are located by convention, and for good reasons. The sewer is the deepest
Lynch, Site Planning, p.141-142.
because it is least likely to malfunction, requires significant grade variations (to maintain gravity flow), and if it does break, gravity will pull the wastes away from the waterline. Water is on the north and east sides of the street, 10' horizontally from the sewer and 5' deep. Gaslines are on the opposite side from water and 4' deep. Electric, telephone and cable TV are behind the curb.
Sewer plans and profiles are designed next, but their principles and requirements have been taken into account in the previous designs. Gravity is the key to sewer systems. Manholes are placed at grade changes or intersections, with the maximum interval being 400'.
Pipe diameters are a function of the number of units served, their density and the slope of the pipe. Mains are at least 8", service lines are 4" to individual dwellings and 6" or more to buildings. Mains should be at least 9' deep to drain basements and allow for 2.5% slopes on services.
Plastic pipe (PVC) is used most frequently. Ductile iron pipe (DIP) is used in more critical situations such as; shallow depths (6'), deeper depths(14') and flatter slopes (.4%). It is significantly more expensive, though. Where alkali soils exist, electrically charged anodes are employed, or paper pipe is used to reduce the potential for corrosion.
Water plans are simpler to design since only capacity needs to be considered. Sizing is a function of density and units served, however fire requirements also play a major role. Fire hydrants are placed at 500' intervals. Valves are built at intersections or 600' intervals to allow isolation of each line in case of a break. Blowoffs are required at the end of pipes if a hydrant is not required.
The preliminary drainage study is completed as part of the subdivision requirements. It is described by Lynch^, and consists of breaking the site down into various basins, determining the runoff flows across each and the resultant capacity requirements.
The final drainage plan further refines the study's results. Every source of water is assessed as to where it will flow and what systems and capacities will be required. Usually overlot flows are directed into the streets and their gutters, they cross streets (usually at intersections) in cross pans, then into inlets at low points and finally into the drainage structures. These include underground pipes (RCP-reinforced concrete or CMP-corrugated metal) or above ground (grass, rip-rap or concrete). Where major drainage flows are carried
^Lynch, Site Planning, p. 172-179.
above ground, crossings may be required which take the form of steel culverts, concrete box culverts or bridges, depending upon the span and water flows.
Gas, electric and telephone are designed and built by the utility involved, however a few considerations are important to keep in mind. These are; the lead time required for design and then construction and that these subcontractors are not responsible to the developer so the timeliness or quality of their finished product is not as controllable.
Electricity is transported at high voltages and then used at lower voltages. These are called primary and secondary respectively, and transformers are required. Underground vaults are frequently required for transformers. Lines may be above or below ground. Telephone lines carry a "pair" of lines for each telephone. These are continuous all the way to a switching station.
Classification of soils is based upon particle size which determines the characteristics of that soil. The primary types of soils are clay, silt, sand and gravel'"''". A quick rule of
""'"Lynch, Site Planning, p.51-59.
thumb is that these basic types can be differentiated by studying a sample in your hand; sand can be seen by the naked eye, silt can be felt by the fingers, and clays and gravel represent extremes of the continuum.
A subarea of soil types is organics. These are made up of various plant or animal materials and they not stable for construction, since they are still breaking down. The state, of decay determines their descriptive name; peat, muck or sludge.
It is vital to understand the makeup of all soils on a land development project, because each classification has its own-characteristics and limitations. Lynch's description is excellent however it is important to emphasize the concept of well graded soils. Poorly graded soils have particles all the same size which results in instabilility. Well graded soils are important for any foundation whether for buildings, roads or any other improvement.
However, the simplicity of soil studies ends here. Usually, the makeup of a sample, is an elaborate mixture of all of the fundamental soil types. Problem Areas of soils represent the single most expensive and unknown portion of the land development process. Anticipation of soil problems is difficult at best and frequently impossible. Among the issues facing a
soils engineer are; high ground water permeability, bearing capacity, shrink-swell potential, erodibility, and stability.
High water tables make construction and sometimes habitability very difficult. Virtually every piece of ground has water at some depth below the surface. When the level of water is deep it presents no problems, except for drilling wells. However, shallow ground water fills utility trenches, slows or stops heavy equipment and may eventually fill basements. The lack of predictability of ground water compounds its potential danger. Soil types affect water's rate of flow and certain clays are impermeable. Underground pressures may force the water to the surface, as will heavy equipment, creating impassible bogs. The key is to anticipate water problems by studying drilling logs and to recognize wet conditions during construction. On some sites it may be necessary to dig a drainage channel before beginning construction and building a permanent cutoff drain.
Permeability is the ability of a given soil to absorb water. It is important in evaluating drainage requirements and septic system designs. Different soil types absorb water at different rates, so projections of expected runoff will be lowered if more water is absorbed. The smaller the soil particles and the better graded, the less permeable the soil.
Eearing capacity is the ability of a soil to maintain stability under a load. It is an issue that is important in the construction of roads, bridges and buildings. Soil types which
have relatively uniform particle sizes (or poorly graded) are susceptible to moving under heavy weights. The resulting instability can be disastrous. Clays present the greatest danger.
Erodibility relates to the potential for a soil to be moved via water or wind which results in water and/or air pollution and lost soil material. Silty soils and to a lesser extent sands are susceptible to this problem however it is a concern on all job sites. The solution is to minimize the amount of tine the ground is without vegetation, to keep adequate moisture on the soil while it is exposed and to create wind and water barriers. These barriers include snow fences, hay bales in drainage swales detention ponds and leaving existing vegetation wherever possible.
Stability is more a geological and planning issue than a soil and land development issue however it warrants attention because it should be considered during project design and construction. Rock falls, landslides and ground subsidence usually occurs because of human activities and they generally are evident after a project is built and occupied. Rock falls are caused by building under unstable formations where weathering actions can cause random bombardment. Landslides are frequently caused by excessive cuts into hillsides and removal of vegetation. Subsidence is a function of natural underground erosion or
shallow mining activities which nay cave in under weight or with tine.
Preliminary Testing starts with a visual reconnaissance of the property with special attention paid to evidence of surface disturbances (eg. soil types in existing cuts, surface water and hazard areas). A series of core drillings are taken over the entire site. Samples are taken at regular depth intervals and these are evaluated using proctor tests and other tests. A bar graph is produced which shows the various soil types by elevation below ground, as well as the water table height.
From this data the soils engineer determines what conditions are likely to be encountered and forwards his recommendations to the design engineers. These factors will be reflected in the design as well as the construction and material specifications.
A soils engineer performs a proctor test which involves drying a sample, passing it through a series of sieves to classify it by type and then weighing each constituent part. Out of this process, optimum moisture content and maximum compaction can be determined. The numbers generated from these tests are vital to field testing and their applicability is discussed in the compaction section.
Compaction and Testing is more an art than a science. Over the
years a variety of methods have been established. The simplest
is to push the edge of ones heel into the ground and see if it
leaves a mark. The cone test is the most accurate. It involves
comparing a samples wet and dry weight to a standardized sand.
The sand is poured into the sample's cone-shaped hole to
determine the volume removed and then it is compared to the
original sample. A secondary method uses the pressure required
to pop a balloon in the hole. These results require time to
prepare so faster methods are frequently chosen In the most common method a field technician, under the direction of an engineer, uses a radioactive testing devise which determines soil density and moisture content. The proctor values for maximum compaction, which were mentioned earlier, are divided into the density values established by the testing devise and a percentage of compaction is determined. Minimum percentages have been established by the FRA and local public works department according to what is to be built on a given location.
The art of soil testing is a function of the variability of soil types which can change dramatically in only a couple of inches. Each proctor is a function of soils in a specific spot, however
Mr. Raymond Childs, Monks Construction, 10/84.
it is unrealistic to sample of every soil type. Thus the technician must be capable determining what proctor if any is appropriate. This decision is critical to the subcontractors because a failed compaction test may require expensive machine time to bring an area into compliance if in fact it can be at all.
The surveyor represents a vital member of every land development team. It is his responsibility to establish the location for each improvement both horizontally and vertically. A surveyor converts the plans into specific points on the ground and then determines their depth or elevation relative to existing grade. Each step in the construction process is preceded by staking of the ground where construction is to occur.
Errors can be extremely expensive, especially when a facility is mislocated and has to be torn down and then rebuilt. Accuracy is frequently maintained to the hundredth of a foot.
The surveyor's equipment includes a transit, rod and tape. The transit contains a level, compass and a system for determining angles. The rod is a stick with stadia for establishing vertical distances. The stadia or horizontal increments are
frequently supplemented with a target of known elevation. This target is constantly referred back to, since temperature changes can affect the settings of the transit. The tape is simply a heavy steel tape measure for determining horizontal distances.
Modern surveying equipment includes a variety of exotic and now necessary tools for the office and field. Calculators and radios for easy field calculations and communications are vital to survey crews. Laser transits provide new levels of accuracy and can measure distances automatically.
Topography is created using aerial photography (called photogrammetry) or on the ground with a transit (esp. for smaller sites). A topographic map should be drawn before the site plan is created. For aerial photography, a series of control points or panels are established and marked, and then pairs of photos are taken from a known altitude directly over the site. These can be interpreted using stereoscopic lens systems to draw the contours. When using a transit, a series of points are determined (esp. at grade changes) and these are interpolated to establish contours.
Control points are established around the site to allow easy takeoffs when a particular survey is required. These points have known elevations and locations are established to allow quick access and easy reading from many locations. They must be clear of all construction activity. Since the ground is
constantly moving it is important to establish these points on solid surfaces preferably concrete, several feet deep.
Staking is the method surveyors use to communicate where construction should occur. Stakes are usually made of wood, pounded into the ground and then marked to define the location for construction. Types include lathe (4'xl/4"xl" strips) for overlot grading, hubs (6"x2"x2"or 8" nails) for establishing exact points on the ground, and stakes (18"xl"x2") for most other construction surveys.
As Builts are drawings which determine the actual location and construction of facilities. They are used when design changes were made during construction or where construction inaccuracy or errors may exist.
When constructing land development improvements, a variety of types of equipment is available. However each piece of equipment is designed for a particular task and as such inefficiencies may develop. Listed below are the primary categories of land development equipment, with a description of their purpose. The goal here is not to circumvent the expertise of the subcontractor, but to provide enough basic information to
allow rational discussion about what equipment might be appropriate.
Beyond the category of equipment to be used, is the size. A variety of sizes is usually available and certain considerations are important in choosing which one. The larger the machine, the greater its capacity and its weight. The weight affects its tendency to pump, its maneuverability, and its transportability. Ground water may be "pumped" to the surface by heavier machines. This creates impassable bogs and failing soil tests due to excess moisture content. Maneuverability affects the turning movements available and the cycle time. A machine that carries more may not be that much more efficient if it moves that much slower due to site conditions. Finally a piece of equipment must be transported to the site. If roadway usage restrictions or the sheer cost of transportation are prohibitive, a heavier piece of equipment may not be feasible.
Bulldozers are crawler-type, track driven vehicles used for pushing dirt or scrapers. They have a variety of blade types depending upon how they are used. Dozers are the most versatile of all equipment both in their intended tasks and the terrain in which they can operate. Usually a ripper tooth is mounted on the rear which can be lowered and pulled through hard soils or rock.
03B D4E D5B D60 D7G DSL D9L 010
Scrapers are used for loading, hauling and dumping soil over distances of 250 feet to 2 miles. They come in sizes ranging from 11 cubic yard capacity to 44 yards. Loading a scraper requires a great deal of power so various systems have been developed to aid in this process. The most common method is by a pushcat or bulldozer. Self loading scrapers employ either elevating paddle wheels, tandem engines (front and back) or push-pull hooks connecting scrapers together to form a train.
6278 831D 651B
Compactors come in a variety of designs and sizes, some are self propelled and some have a blade for limited dozing applications. Vibratory sheeps foot are used in clays where their fingerlike projections and vibration, to knead the material together.
Smooth drums and tired vehicles are generally used on sandy or gravely soils. In particularly difficult conditions, a hydro-hammer is useful. It drops a weight rhythmically over a small area (less than a square foot).
81 SB 825C
Water trucks usually have a 1000 to 10,000 gallon capacity. They must have a source of water (hydrant, pond or well) and a
system for spreading their load. Water is a vital component of soil compaction and dust pollution reduction.
Loaders is usually a wheeled tractor with a bucket attached, although track driven loaders are also available (for steep terrain or to avoid tire punctures). They are used for loading trucks, backfilling trenches and excavating, especially in tight conditions or where accurate cutting is required. On small projects (less than an acre) they frequently become an all purpose vehicle; acting as dozer, scraper, grader, compactor and of course loader. Bucket sizes range from a yard or less to 13 yards. On smaller loaders, a backhoe is attached to the rear.
910* 920 930 950B 966D 980C 988B 992C*
Blades or graders finish and shape the land into its final form. These machines have a multitude of controls for adjusting the moldboard's pitch, angle, height, reach plus the wheel's angle and pitch and the body's articulation. Ripper blades are attached to the rear for scarifying hard soils.
120G 130G 12G 140G 14G 16G
Backhoes are employed in digging below grade for excavating trenches or in difficult to reach conditions. Sizes are defined
primarily by arm reach (10' to 30') and bucket size (one-half to three yards). Backhoes are frequently used for placing material into trenches (eg. pipe).
215* A 215 SA* 225* 235 245
Trucks are generally used for hauling longer distances and specialized loads. They come in a variety of shapes and sizes including; dumptrucks (5 to 12 yards), end dumps (20 yards), riprap trucks (rock), belly dumps (spreading material) and off road trucks.
Concrete placement is either done by track driven slip formers or by hand placed forms. Usually concrete is provided by a batch plant via trucks. The mixture of cement, aggregate and water is varied according to application as is the placement of reinforcing steel (called rebar). Many additives are available for concrete which will affect the way it hardens. A cure is always applied to unformed surfaces to minimize excessive drying before the concrete cures. Special concern is required in freezing conditions since concrete must not freeze before it cures. Slump testing involves placing a sample in an 8" cone and determining how many inches it slumps down. The less it slumps the less water was used per part concrete and the harder the concrete will set up.
Asphalt requires the use of batch plants to mix the aggregate and oil which is then trucked to the spreader. Spreaders come in a variety of sizes and sometimes are simply a grader.
A list of specialized equipment is listed below which is used, occasionally. Pipelayers have booms attached which are used to lower pipe into trenches. Other members of the backhoe family include draglines, clamshells, cranes, shovels and piledrivers.
The jobsite should be organized properly before beginning construction. This may include demolishing unusable structures, establishing access routes and creating a construction yard.
The access routes should be located in safe locations (esp. adequate street sight lines, overhead clearance and out of major construction areas). Gravel (1" aggregate) should be spread at these exits to help clean tires, since tracked mud is a primary source of construction air pollution. The construction yard should be flat, out of construction areas and have good access and security.
The entire process is intimately tied to the seasons and weather. Ideal conditions would be humid, but no precipitation with temperatures of 60 to 90. Frost, rain, snow, zero
visibility and arid conditions can slow activity, increase costs and even shut down a project.
Where swampy or wet conditions exist, drainage should be established well before construction begins so these areas can dry. Underdrains may be needed to provide permanent drainage. These are built out of perforated pipe and rock which is wrapped with a permeable cloth (to avoid clogging) and then buried below all potential activity.
Subcontractors are usually used to complete each segment of the process. Their expertise in a given specialty helps them to complete their task, hopefully in the most cost and time effective method possible. The land developer makes a bid request for a specific task and then chooses the subcontractor who is economical, qualified and can complete the task in a timely fashion.
Overlot grading is the process of moving dirt around the site to conform with the patterns required for development. Streets and drainage facilities are roughly constructed.
It begins with removal of all organic soil materials. This includes stripping the topsoil and clearing required brush and trees as well as grubbing their roots. Elevating scrapers are most effective on topsoil although dozers or loaders can be used.
The surveyors stake the streets and major grade breaks.
Location is more important than elevation so the vertical
tolerance is usually a tenth of a foot. On especially flat
sites even tighter specifications may be required, however on
sloping sites 2 and even 3 tenths may be acceptable The key is to assure drainage and smooth transitions. A grade checker helps the equipment operators determine the appropriate depth of each fill and will offset measurements from stakes to minor grade breaks. This includes shooting the grades of offsets marked on original stakes, marking cuts or fills on stakes and offsetting stakes as elevation changes require (eg. fill activity covers over stake).
Haul roads for the scrapers are established which connect cut and fill areas. These routes generally conform to the finished street layout whenever possible and they should be constantly maintained by watertrucks and the grader to maximize efficiency.
Dirt for fill areas is placed in lifts of 6 to 24 inches. Water is added to achieve optimum moisture and the compaction equipment works the soil. A soils tester then has a slight cut made and checks at certain intervals for adequate compaction.
If a test fails the soil is reworked and additional tests are taken until the specification is met.
Hr. Michael Mallon, Mallon Development, 10/84.
On slopes steeper than 4:1 the equipment must bench into the slopes to create flat pads for driving on and compacting. When rock is encountered, the ripper blades behind the dozers are lowered to break it up or in harder rock explosives are used. Generally the scrapers are employed throughout this process, with the other pieces mentioned in the equipment section being used when available and appropriate.
Another task of the soils tech is to assure that soils are placed in acceptable locations. Frozen soils can not ever be used as fill. The topsoil which was originally stockpiled, must be redistributed on the site, however it cannot be placed anywhere construction will occur. This includes building pads and streets. Thus, it is usually placed in the rear lots. If clays exist in building locations, overexcavation and placement of acceptable materials may be necessary.
> i? ;
After each area has been completed, the ground should be seeded with grains or grasses. Usually a quick growing perennial is appropriate, and fertilizer will be helpful as will watering.
In some locations a mulch of hay, straw or wood chips should be spread which may substituted with commercially sprayed products called hydro-mulch. On slopes over 3:1, woven wood and plastic blankets (jute or excelsior) may be staked to the ground and on steeper slopes more exotic products are available (Enkamat) .
Mr. Stanley M. Brown, North American Homes, January 1984.
All of these systems are designed to stabilize the soil long enough to get root growth started thus preventing erosion. Air pollution may be further reduced through the use of snowfences at critical areas and property lines. Water pollution may be reduced during construction by employing; sediment basins, slope drains or mulch materials.
Sanitary sewer and water is generally laid by the same pipe-crew. It is important to note the importance of locating existing lines before beginning construction. Usually each utility will locate each line free of charge, since down time is troublesome to customers. The cost of repair can be incredible and the cutting of high voltage electric lines or gas 15.nes can be deadly.
The sewer pipe is placed 8 to 20 feet below grade in the center of the street. As a backhoe digs a trench each joint of pipe is placed. Spaces are left for the manholes. The manholes are constructed shortly there after usually employing precast rings of concrete which are stacked to the proper elevation. After a line is laid, services are installed to behind the property line which will eventually connected to each building. Care must always be taken to minimize the amount of trench open since precipitation can instantly turn each trench into a swimming
Staking is done using 10 to 25 foot offsets so the stakes will still be usable after the digging is completed. They are placed on the opposite side from where the spoils will be. The contractor then sets the line using a transit, a laser through the pipeline or a crazy leg.
Soil conditions can make construction difficult and hazardous. High ground water tends to float the pipe as it is laid and can cause the trench banks to slough (sometimes burying workers). Sandy soils are particularly susceptible to sloughing and it is a constant danger in deeper trenches and in some conditions a shoring box may be required to hold the walls in place.. Stabilization material (sandy soils) may be required in clay soils especially in deep trenches.
The water line is laid 5 feet deep on the north or east side of the sewer (the gas line is on the opposite side). Water is placed more quickly than sewer primarily due to its shallower depth. Staking and services are completed in much the same manner as the sewer. Chlorine tablets are placed in each joint of pipe to assure initial sanitation. The main must be pressure tested before these tablets break-down (in 6 months). Fire hydrants, valves and blowoffs must also be installed. Poured concrete thrust blocks are placed at pipe bends, to absorb the movement created by pressure changes in the line.
Curb and gutter is a critical stage of construction from a surveying standpoint. All stages there after will rely upon the curb location to establish locations and frequently grades. An ongoing debate is whether curbing or water services should be installed first. If curb is installed, it will help locate where the services should be placed, however the curb will also be more susceptible to breakage and it is difficult to obtain compaction underneath it. Once the concrete has set up, backfill must be placed behind the curb to promote drainage and minimize the possibility of undermining.
Gas, electric and telephone are normally installed by their respective utilities, so the commentary here is limited. Scheduling is sometimes more critical since the subcontractors are responsible to someone else. Similarly, the subcontractors may be be demanding that the site be in a certain state before they will begin construction.
Paving itself is relatively fast and simple, given favorable weather conditions. However, paving represents the culmination of all of the land development steps and thus can become quite complex.
Manhole heights are adjusted to within 8 inches of the final pavement height. After paving they can be further adjusted to the actual paving height using rings. The subgrade is compacted and grading to the proper elevation with the street crown
created and compaction tests are taken at regular intervals.
The results of these tests together with compaction tests for all of the utilities are presented for approval of a base letter.
The base letter allows the base to be hauled, graded and compacted. Base is a well graded material which provides a firm foundation for the road and turns as hard as hobs of shit when properly compacted. Density tests are again taken.
The water valve boxes are raised to the top of the base. Frequently the valve boxes are full of dirt, broken or they cannot be found at all, even using a metal detector. A similar problem revolves around curb repair. Usually an entire 10' section must be replaced by hand if a broken piece exists. This problem tends to be ongoing even after land development is completed and building begins.
The compaction test results, valve box inspection and manhole certification of height are all presented for a paving letter. Paving can be started immediately if the contractor is ready and weather permits. Weather is a particularly important issue since paving cannot be performed if the base is wet, frozen or excessively eroded.
The asphalt mix is a minimum 5.5-6.5Z oil with 3/4" clean aggregate base. Asphalt should not be laid in temperatures
below AO degrees, 50 degrees after an evening frost or whenever precipitation is falling. The mix must be at least 125 degrees when laid. A primer coat must be applied to all concrete surfaces. The surface is rolled repeatedly with a smooth drum to draw the bitumens to the surface and consolidate the asphalt. Adherence to strict quality standards is vital to assuring durability.
Essentially land development is completed at this stage. The project is ready to be turned over to the construction people so the building may begin. There will be ongoing questions about what was done, and the level of detail of documentation will payoff. Whether it involves the location of a service, the depth of a gravelly fill or why a design change was made, you can plan on questions. A logbook plus as-built drawings will be invaluable.
If you get to this stage of construction on schedule and under budget you deserve a big star or at least a raise. If you got to this stage without any problems, you are a liar.
The reader should begin to understand the reasoning behind the land development process. Every step which has been described above is done for a specific reason. If nothing else land development is practical and functional. Frequently, the
unknowns of the land make the process an art, however the goal remains to create a pragmatic series of steps which will achieve completion of the project in the most efficient manner possible.
The challenge for the land developer is to orchestrate the various subcontractors into an orderly and cost effective symphony. The process is by nature very expensive, both in running the crews and equipment and in the cost of downtime, delays and interest payments. Problems must be anticipated, even though they are frequently invisible initially.
Planners can not have to become experts in every profession which affects their recommendations or designs. Planning is full of unknowns and land development only adds to the list.
The goal becomes to understand the process well enough to be able to incorporate its principles into planning decisions.
The value of understanding the basics of land development go beyond knowledge for its own sake. Outlined below are some of its direct applications for planners. Each of these topics could serve as a departure point for further studies.
Planners occasionally find it difficult to communicate with engineers. This is partly a function of engineer's technical knowledge and vocabulary as well as their way of thinking. However, planners are still expected to work with engineers. A better understanding of the issues engineers deal with will help in reducing whatever misunderstandings might exist.
Good site planning is in large part a function of integrating a variety of factors into the design. This includes marketing, sociological, architectural and engineering issues. Many of the engineering factors have been covered in this document or in Lynch. Quality design can not be achieved without incorporating these considerations as well as others.
Soils engineering is a complex and inexact science. The unknowns of each site's soils and their respective properties make it imperative that adequate soil investigations be completed. Planners should strive to understand the fundamentals of soils, because soils affect the built environment so significantly.
Given the complexities of soils and soil variability under the surface, it is hoped that the reader can recognize the inadequacies of the county agricultural soil maps. These maps only deal with surface material and are occasionally inaccurate. Subsurface materials can be drastically different. These maps should not be ignored, but should serve as preliminary soil type indicator and as confirmation of core drillings.
A list of soil hazards was included in the text. The description is limited and should serve as an introduction. Identification of these hazards should be a constant goal for planners and each warrants further study.
Maps represent a primary language for planners. Surveyors are one of the primary sources of maps and legal descriptions. An additional benefit of understanding surveying comes when one attempts to review on site staking, whether for building locations, property comers or cuts before grading begins.
Particulate air pollution in urban areas is usually directly related to construction activity. Control can only achieved by reducing mud tracking onto streets and wind erosion. Ordinances can be written to reduce the problem, but further study of the issue must be combined with an overall knowledge of land development
Cost estimates are a vital segment in feasibility studies and site evaluation. The private planner must always be aware of cost considerations and the public planner may need to utilize cost estimates in comparing public facility sites or in preparation of capital improvement programs. A similar feasibility issue relates to the carrying capacity of various infrastructure improvements. This issue has been not covered, but the terminology and workings of each utility has been covered. This topic warrants extensive research especially when evaluating specific sites or in lobbying for infill activity.
On a similar line, scheduling can be important to private or public planners. Special attention must be given to the order of events, their length and prerequisites.
Each of the topics discussed above could be studied in greater detail. In some ways this brings us back to engineers who see confused planners expecting improvements to be built without understanding the framework of the process. Knowledge is a prerequisite for anyone seeking to manipulate the world for the better. Only by learning as much as possible about all the issues facing us, can we as planners hope to create a better community.
For the planner who wishes to go beyond the traditional roles of planning, land development offers a logical option. Usually the planner brings a knowledge of development processes (eg. market analysis, zoning, site planning) and an interest in the development process. Planners can make good developers, but usually they lack the knowledge to undertake such a role or even understand what that role requires. The previous discussion explores one facet of that role, and opens the door toward further discovery.
One aspect of land development, from the field direction standpoint, which was not discussed above, is what the job entails. The practitioner is expected to juggle a variety of different responsibilities to perfection. Forgetfulness is sometimes punished with delays many times the original error.
For example, from the planner's perspective, the missed subdivision submittal deadline usually means a month's delay. This penal system carries over into most aspects of the job
including; obtaining bids, allowing sufficient lead time, coordinating contractors on the job site, and making sure each job is completely finished. Similarly, the cost of land development makes all decisions potentially bankrupting.
Land development requires a problem anticipating and a problem solving way of thinking, which in many ways is like a planner's. The days are usually long but with so much to keep in mind, the days move quickly. There is a special satisfaction in seeing your decisions have such a dramatic impact on the land.
Knowing the productivity of subcontractors is critical to scheduling and completion of a project on time. Listed below are some rules of thumb on productivity. These are subject to variability due to contractors expertise, weather conditions, soil conditions and innumerable other unknowns. It is important to remember that construction usually can not begin until the governmental approvals are received and the previous subcontractor is finished. These rules assume only one crew will be utilized, greater production may be achieved with more workers although efficiency may drop. The chart assumes an average size single family project (eg. 100 units on 30 acres).
Earthwork 3000 yd3/day
Sewer (main) 600 If/day
(manholes) 3 each/day
(services) 15 each/day
Water (main) 800 If/day
(hydrants) 3 each/day
(services) 15 each/day
(cleanup) 2 days
Curb and gutter (setup) 2 days
(concrete) 1500 If/day
Electric (delays) 10 days
(construction) 10 days
Gas (delays) 7 days
(construction) 8 days
Paving (prep) 3 days
(subbase) 5 days
(base) 5 days
(pave) 2 days
Note: If means linear feet and yd3 means cubic yards. ^Mr. Michael Mallon, Mallon Development, 10/84.
Cost estimates begin with determining the quantities of materials required. Measurements are taken off of the various plans according to the specified materials for construction. The figure below indicates the units of measure usually used as well as some rules of thumb for double checking the estimates (the rules of thumb relate back to the centerline length of the street). The prices are current in 1984, however they are subject to change. A rule of thumb is included to double check the results of each quantity take off. Unless otherwise noted the equation relates to the street centerline.
Activity Cost16 Unit Relation to Centerline
Sewer 8" 9.50 If 10-20% less
12" 16.25 If
15" 24.45 If
Manholes 850.00 each divide by 250
Services 180.00 each equals number of lots
Water 6" 9.25 If equal to centerline
8" 11.25 If
12" 18.00 If
Hydrants 1510.00 each divide by 500
Valves 425.00 each divide by 250
Fittings 300.00 each
Curb & gutter 4.90 If times 2 minus 10%
Flatwork 3.00 yd2 (concrete)
Base 11.00 yd3
Paving 3.50 ft2 times width divided by 9
Zoning Plattinq Prelim and final $100/request $150/request
Park less than 8du/ac $279/unit
School more than 8du/ac less than 8du/ac $198/unit $240/unit
Drainage more than 8du/ac varies by basin $58/unit $2112/acre
Bridqe varies by basin $73/acre
Wastewater multifamily=$/4/unit $864/unit
Water unincorporated areas 3/4" tap $1079/unit $40 each
Electric 8"x8" tap 3/4" single family 3/4" sf unincorporated single family $1326 each $2698/unit $5040/unit $408/unit
Gas sf with electric heat estimated for sf $1058/unit $400/unit
. Stanley M. normal use rebate Brown, North American Homes $265/unit 6/84.
Below is an imaginary project which will be used as an illustration for this paper. The project is approximately 3 acres in size and it slopes from a collector street to a minor drainage. A standard cul-de-sac street has been designed which provides access to 12 single family lots. Each of the design processes described above has been applied to this project including; site plan, grading, streets, sewer, water, quantity estimates, cost estimates and projected time schedule.
Grading is confined to the site, however offsite grading would be more favorable since the slopes on the east and west could be minimized. The units on lots 6 through 9 would require walkout basements or a similar device for taking up grade.
A collector street is assumed to be preexisting, with a sewer manhole and fire hydrant already in place. The sewer and water lines are assumed to be adequately sized as well. The sewer drains toward the collector street which is contrary to the natural slope of the land. The depth is not excessive though, because the cul-de-sac is relativly short and minimum sewer pipe grades are used.
The street drainage flows in the opposite direction; toward the ravine. A crosspan is indicated which will pull water across the collector street and then down the cul-de_sac. A drainage easement is indicated between lots 6 and 7.
It is significant to note that the per lot cost estimates include only the land development costs, but they do not include interest carrying costs, consultant fees, or the actual land purchase. As a frame of reference carrying costs for land development would be 1 to 2l per month of the outstanding balance and land might run between $.25 and $.75 per square foot. Engineers' usually cost 41 of the total land development construction bill and surveyors receive a similar amount.
The time schedule and cost estimates assume that a larger project is to be constructed. Time frames and prices tend to expand for smaller projects so that it is better to work with sites of 10 acres or larger in order to take advantage efficiencies of scale. Start up times and costs for contractors represent a significant portion of the total in a 12 lot, 3 acre site.
ca 0(p 04 01 U><700 %
C8 04 oi (*$00 M
l; ip 2 X
CHUCK"S ACRES LAND DEVELOPMENT
1 FILING #
50 ROW (LF)
32 FLOWLINE 28 ASPHALT WIDTH
0 ENTRY (SY)
65 CUL (SY)
QUANTITY ESTIMATES MEASUREMENT UNIT QUANTITY UNIT
CURB TYPE 2 4 GUTTER WIDTH
CURB/GUTTER 876 LF 876 LF
CURB RETURN 2 EACH 48 LF
RADIUS PAN 1 EACH 118 SF
CROSS PAN 1 EACH 168 SF
CENTERLINE 246 LF
ROADBASE 6 DEPTH (IN) 135 CY
PAVING 2 DEPTH (IN) 812 SY
SEWER MAIN 8" 303 LF
SEWER SERVICES 12 EACH
MANHOLES 1 EACH
WATER MAIN 6" 292 LF
WATER SERVICES 12 EACH
FH ASSEMBLY 1 EACH
GATE VALVES 2 EACH
FITTINGS 1 EACH
PRICES QUANTITY PRICE/UNIT TOTAL
DIRT 7600 $1.00 7600
CURB/GUTTER 876 $4.90 $4,292.40
CURB RETURN 48 $4.90 $235.20
RADIUS PAN 118 $3.00 $354.00
CROSS PAN 168 $3.00 $504.00
ROADBASE 135 $11.00 $1,488.06
PAVING 812 $3.50 $2,840.83
SEWER MAIN 8" 303 $9.50 $2,878.50
SEWER SERVICES 12 $180.00 $2,160.00
MANHOLES 1 $850.00 $850.00
WATER MAIN 6" 292 $9.25 $2,701.00
WATER SERVICES 12 $175.00 $2,100.00
FH ASSEMBLY 1 $1,510.00 $1,510.00
GATE VALVES 2 $295.00 $590.00
FITTINGS 1 $300.00 $300.00
MISCELLANEOUS (15%) $4,560.60
CITY FEES PER UNIT PER ACRE PER PROJECT TOTAL
ZONING $100.00 $100
PLATTING $150.00 $150
PARK $279 $3,348
SCHOOL $240 $2,880
DRAINAGE $2,112 $6,336
BRIDGE $73 $219
WASTEWATER $864 $10,368
WATER FEES $2,698 $32,376
TAPS (3/4) $40 $480
TAP (6x8) $1,165.00 $1,165
ELECTRIC $408 $4,896
GAS TAP $400 $1,620
CITY FEES $63,938.00
CONTINGENCIES (10%) $9,890.26
CHUCK'S ACRES, f 5 S i or. 1. IMl.'M. : W CHUCK. DAT A Preoind bv DONLEY
D*c F ilir 4Â£r *u Jur. JV Aye 5 K
Job Discripticr. 12 19 28 3 10 17 24 31 7 54 21 28 4 r. 18 25 4 13 25 9 15 22 29 i 13 20 27 3 10 17 24 1 8 15 22 29 12 19 28 2 9 18 2:
7 2 3 4 5 8 7 8 6 I? 11 12 13 14 15 If 17 18 19 20 21 22 23 24 25 28 27 28 29 30 21 32 33 34 35 38 37 38 39 4C 41 <2 4C 44 45 46 47
2 PRELIRINAR- eL*T
3 FI HAL PLAT
5 GRADING Plan
6 APPROVED GRADING Pt
7 DRAINAGE STUDY
8 APPROVED DRAINAGE STUDV
9 LETTERS 0? CREDIT
10 FLAT RECORDED
u SEVER plans aselW
12 SEVER PLANS APPROVED
13 WATER PLANS PREL!"
14 WATER PLANS bPOVEI
15 STREET LANS APPROVED
lb STORN SEWER PLANS aPPfiO'-ED 1? CLEARING AND GRUBBING
19 OVERLOT GRADING
28 SLOPE STABILIZATION
21 CORROSION TEST INC-
22 SEWER HA In
23 NAMHOLE CONSTRUCTION
24 SEWER SERVICES
25 WATER pain
28 LOAD AND TEST RAIN
27 WATER TAPS
28 WATER SERVICES
29 DRAINAGE STRUCTURES
30 STOH SEWER
31 CURB AND GUTTER STAKES
32 CURB AND GUTTER
33 CURB RETURNS
34 BACKFILL C/G
35 ELECTRIC DESIGN COHPtET?
38 LEAD TIRE ELEC COwST
37 ELECTRIC CONSTRUCTION
38 GAS DESIGN
39 GAS CONSTRUCTIGi-
41 CROSS PANS
42 SUBGRADE PREPAFcTJO--
43 BASE RERRIT
Job Description 45 PAVING PERHIT
No*.- D*c Jin Feb r..r nor 'iv Jyr. Jul auo Si: ':*
13 19 28 3 10 17 24 31 7 M 21 2* 4 11 18 25 4 11 18 25 1 B 15 22 29 i 13 20 27 3 10 17 24 I 8 15 22 29 5 12 19 28 2 It 2? 8 7 14 >1
0 I 2 3 < 5 8 7 8 15 II 12 13 14 15 18 *7 18 19 20 2. 22 23 24 25 28 27 28 29 30 31 32 33 34 35 38 37 38 39 *i 4i 42 43 44 4* k 4* 4* <
47 FINISH GRADING. DRESS V?
Sorting order Cv^enr *ro*r Fro* the fir it jot t: the list ;ct Jobs using til skills
>> Durition e* jot
>..> Slick tM *cr i r.;rl ..;t >**> Durition cR i cr t;c* :* ::
?::: Durition :R coipinec ;:t
Job Kith urc durition
O> Job uith *: rrir*3ui*lt*f
>X Job th n; juCCmori
' Ti :fM oue t: hoi idly '' <*** of*
1. city standard base course-refer to city standard specifications.
2. SUBGRADE (COMPACTED IN ACCORDANCE WITH CITY STANDARD SPECIFICATIONS)
3. BASE COURSE DEPTH (VARIES ACCORDING TO STRUCTURAL DESIGN) (H VEEM TEST REGD.)
4. REFER TO CITY SUBDIVISION ORDINANCE FOR REQUIRED ROW AND STREET WIDTHS AND OTHER STREET SECTIONS
5. REFER TO STANDARD DETAIL FOR CURB AND GUTTER (TYPE I AND TYPE 2)
CITY OF COLORADO SPRINGS, COLORADO
STANDARD STREET SECTIONS
Meja* CITY ENGINEER
DATE: iUJNE 1980
| DRAWN BY
STANDARD STREET CROSSECTIONS CITY OF COLORADO SPRINGS
ICO 'row. COLLECTOR
60' R O W. -------------------------------------------------
STANDARD STREET CROSSECTIONS
TYPICAL CROSS SECTION UTILITIES LOCATION 60' R OW. COLLECTOR STREETS
I) STORM SEWFRS SHALL MAINTAIN A 10' SEPARATION FROM WATER
t) ELECTRIC CONDUITS SHALL BE ON THE OPPOSITE SIDE OF THE STREET FROM WATER
CITY OF COLORADO SPRINGS or rcmiuc utilities Y/ATER DIVISION
TYPICAL UTILITIES LOCATION > ;
*mmw* t) [MT* U }**. r's |'-0"
JOm mo -Oifi ao
FIGURE 7 BOLTS
SEE ACCEPTABLE ALTERNATIVE MAIN CONNECTIONS BELOW
CONCRETE REVERSE ANCHOR. SEE DRAWINO NO. 18
CONC THRUST" REACTION BLOCK
CONC. THRUST BLOCK ( TYPICAL) SEE OWG. NO. 10
TAPPING SLEEVE WITH UAU/E
ANCHOR HYO TEE ft VALVE
x IS(MINJ CONC. BLOCK
MJ HYO TEE WITH 30 SPACER PIPE AND VALVE TIED BACK TO TEE
TIE-BACK ROD WITH FIGURE 7 BOLTS
PROFILE showing 3 acceptable volve ana tee fittings.
PROFILE showing typical vertical offset bend upon inspectors approval.
Cl rv-OP" COLORADO SP&IHG3 & cm****~rf*eni o* *umuiC ut;i_/T7"s a w ATE& Di v / S/O/V |
FIRE HYDRANT INSTALLATION ?
omwm L OTTO ,J*" ll/*P|u**1 y
Mat- u* |*c.'NONE |
JO wo WO iO S
z'-oia. asphalt collar
SLIP TYPE 5V* 1.0. SHAFT
TYLER PIPE SERIES 6855 OR EQUIVALENT APPROVED BY THE WATER OIVISION.
ji ym, aqHzgamAijmBgg^i
C/TV OF COLORADO SPRINGS oci/*rMfNr or fvmu/C ut/i_/tcs WATER Dl V / SION
VALVE BOX INSTALLATION
o*A 0 HAAC =*T*M/K |*"~c
B 0*Tt MI' |M.* NONE I
JO* o ija m |
j t Tsmmfmafsmrmfsgsnm mmam
SOLID COPPER BONOING WIRE THERMOLWELDED TO PIPE, BOTH ENDS, OR BONDING STRAP BOLTED TO PI PE .
NOTE'________________ SECTION A-A
I). CADWELD CONNECTION TO BE PRIMED ANO COATED CAREFULLY PACKAGED ANODE SHOULD BE COVERED WITH FINE SOIL CONTAINING NO ROCKS OR DIRT CLUMPS .TAMPED
2L WHEN ANOOES ARE REQUIRED WITH METAL FITTINGS AND APPURTENANCES TOGETHER WITH PV.C. PIPE INSTALLATIONS, THE ANOOES SHALL BE PLACE ANO ATTACHED TO THE METAL IN SAME MANNER AS SHOWN ON THIS DRAWING
|r/rv of COLORA DO SPRINGS
t / n FTT MEN r f= GUC O flLI TIES
BONDING JOINT ANO ANODE INSTALLATION
[--L.OTTO *2/931 " __
-o ,* >* |'CAtJNOf
DOUBLE WIRE MESH TO BE PLACED IN WALL OF MANHOLE SECTIONS GREATER THAN 20'
4'MH-24" CAP 5' MH- 30"CAP 6 MH- 30" CAP
STEP TREAD TO BE PARALLEL WITH INVERT FLOW DIRECTION.
-GRADE ADJUSTMENT RINGS SHALL NOT EXCEEO 8'.
I ADJUSTMENT RING REQUIRED FOR ALL PRECAST MANHOLES.
MANHOLE DEPTH DIMENSION
O' TO 14 6" 8"
OVER 14' 12" 12"
CITY OF COLORADO SPRINGS WASTEWATER DIVISION EAST.LAS VEGAS
STANDARO CONCRETE MANHOLE
DRAWN AUGUST 14,1978 DETAIL
DRAWN BY : J. D.C. SHEET
APPROVED by: UJp * 1
STANDARD VERTICAL CURB AND GUTTER
STANDARD RAMP CURB AND GUTTER
TYPE 3 SCALE l"=r-0"
STANDARD MEDIAN CURB AND GUTTER
LENGTH FOR RADII
C = lV
0=1^2" to 2V
CITY OF COLORADO SPRINGS, COLO.
STANDARD CURB a GUTTER TYPE 1,28,3
APPROVED BY: n z 1 f / *
SCALE : DATE DRAW* BY DWG NO t
AS SHOWN MAY 78 V. N W D 6
REFER TO DRAWING NO. DIOR FOR CONSTRUCTION OF CATCH BASIN.
w4 BARS <9 9" O.C.
8 SMOOTH REBAR & 18"C/C
4 BARS M H 0PENING-2"CL A-BARS 6*0"
B-BARS 3' 0"
C- BARS 2'0"
SUPPORT BARS REQUIRED WHEN OPENING IS GREATER THAN 4'o"
1-5/8 x 4" CHANNEL (PAINTED 8 ANCHORED TO TOP SLAB)
Pyk ut:-> .-.f. at!:.-
GROUT SLOPE TOWARD OUTLET PIPE.
1. All riprap channels to be grouted unless----x-
otherwise approved by the City Engineer.
2. Riprap shall have a specific gravity of 2 65 or 165 lbs./c.f.
t = 1.5 x (specified
stone diameter)for 18" 48" size,
4 ?. = not less than 2.0
5 The above are minimum requirements only and are not to be considered as a substitute for a complete hydraulic design reflecting local parameters.
GRADED AGGREGATE FILTER OR PLASTI FILTER CLOTH
2.0 x (specified stone diameter);for
MINIMUM RIPRAP SIZING SHALL BE IN ACCORDANCE WITH THE FOLLOWING CHART
CHANNEL VELOCITY (fps) STONE STZE (equiv. diam.)
CITY OF COLORADO SPRINGS
RIPRAP CHANNEL. O
APPROV -D RY tWr&r
NO SCALE 8/80 draWw'by c m 1^: |?
NORTH AMERICAN HOMES
LAND DEVELOPMENT FIELD FOREMAN JOB DESCRIPTION
Reports to the Land Development Manager. Will be assigned one or more projects.
For these projects, the Field Foreman directs, coordinates and expedites subcontractor work. Coordinates construction staking with subcontractor work.
Holds regularly scheduled coordination meetings with subcontractors and engineers. Inspects subcontractors' work for conformance with approved plans and with City and NAH requirements. Approves work or requires contractor to correct deficiencies. Reviews and approves for conformance with field work accomplished and/or with contractual terms, invoices and billings from subcontractors, suppliers and consultants. Approves extra charges in advance and provides necessary documentation to the accounting department. Mediates and expedites, where necessary, the settlement of disputes between subcontractors and between subcontractor and engineer where project schedules are at stake.
Coordinates and schedules consultant's field work. Coordinates with City inspectors, City utility personnel and other regulatory personnel for the purpose of insuring timely inspections and approvals.
Maintains and updates project files, records and drawings pertinent to project land development.
Directs miscellaneous site tasks for maintenance of clean, orderly and efficient project development. Takes necessary steps to maintain a positive external image and to minimize nuisance and inconvenience to neighboring citizens.
Coordinates with and provides input to engineer in the resolution of design problems encountered during field implementation.
Assists the Land Development Manager in review of engineering design work for new projects and preparation of preliminary and final development budgets.
Provides input for budget updates or revisions. Assists Land Development Manager in preparation of preliminary and final master project schedules and updates master schedules as necessary. Prepares detailed weekly project schedules showing actual progress for previous week and projected progress for coming week and provides to Land Development Manager.
Assists Land Development Manager in preparation of bid documents. Reviews and approves engineers and performs own quantity take-offs as necessary. Interviews and aids in selection of prospective bidders. Assists in review of bids and award of contracts. Assists Land Development Manager in preparation of contract documents.
Erinker, Pussell. Elementary Surveying. Harper and Row: Hew York,
Caterpillar Performance Handbook Edition 14. Caterpillar, Peoria, Illinois, 1983.
City of Colorado Springs, Engineering Department, Standard Specifications. 1980.
City of Colorado Springs, Water Division, Standard Specifications, 1984.
City of Colorado Springs, Wastewater Division, Standard Specifications 1980.
Colorado Water Conservation Board. Manual for Estimating Flood Characteristics of Natural Flow Streams in Colorado. Denver, CO: 19W.
Colorado Division of Highways, Standard Plans, 1981.
Colorado Division of Highways Standard Specifications for Road and Bridge Construction, 1981.
Jensen, David R. Zero Lot Line Housing. Urban Land Institute: Washington D.C., 1981.
Lynch, Kevin. Site Planning. MIT Press: Cambridge, Mass., 1979.
Marsh, William M. Environmental Analysis. McGraw-Hill: New York,
Macaulay, David. Underground. Houghton Mifflin Co.: Boston, 1976.
National Association of Home Builders, Cost Effective Site Planning. Washington D.C., 1982.
Nichols, Herbert L. Moving the Earth. North Castle: Greenwich, Conn., 1976.
Nunnally, S.W. Managing Construction Equipment. Prentice Hall: Englewood Cliffs, New Jersey, 1977.
O'Mara, W. Paul. Residential Development Handbook. Urban Land Institute: Washington D.C., 1978.
Real Estate Research Corp. for U.S. Housing and Urban Development, Cost of Sprawl. USGPO, Washington D.C. April 1974.
Schler, Daniel J. The Private Land Developer: A Sociological Interpretation; PhD Thesis. University of Missouri, August 1966.
Steel, E. W.; McGhee, Terence. Water Supply and Sewerage. McGraw-Hill Inc.: New York, 1979.
U.S. Department of Agriculture. Soil Conservation Service. Erosion and Sediment Control. Denver, CO: 1980.
Untermann, Richard and Small, Robert. Site Planning for Cluster Housing. Van Nostrand Reinhold Co.: New York, 1977.
Special thanks are in order for the following people for their help in this paper:
Stan Brown, North American Homes Inc.
Ray Childs, Monks Construction.
Mike Mallon, Mallon Development.