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Site Work
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Major Topics
Site Plans/Surveys Grading Compacting/Erosion Earthwork Soil Surface & Groundwater Paving and Surfacing Materials
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Site Plans Include:
All information shown on a survey Changes in topography or grade Demolition of existing construction Exact location of new construction
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Surveys
Legal description of a piece of land Typically done by a registered land
surveyor Surveys include the boundaries
and elevations of land plots and buildings (in text and drawings)
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Topography or Grade
Contour lines show elevation Closer the contour lines are
together- the steeper the slope This information is critical in
determining how much earth must be moved to prepare site for structure being built
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Grading Both the rough and final grades on a building
site are established by grading, using power equipment and hand tools.
Grading is needed wherever slabs, pavement, walks, and landscaping is anticipated.
Finish grading should slope downward away from the building at a minimum of 6 inches/ 10 feet (about 5 %).
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Compacting
Compacting applies energy to soil to consolidate it by compressing air voids to increase the soils dry density.
Minimizes settling Increases load-bearing capabilities Increases soil stability Reduces water penetration
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Slope Protection & Erosion Control
Building codes often dictate prevention of erosion
Possible methods used include: Filter fabrics – open weaved mats of nylon or
other synthetic materials Riprap – a layer of stone or broken concrete
used to control or divert the flow of water
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Earthwork
Involves some type of cutting (excavation) or filling of soil materials The level down to which the materials are
removed is determined by the contract documents
This phase of site work is referred to as “rough grading”
Soil testing is usually performed at this time
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Fill and Backfill
Soils used for fill should contain no vegetation or foreign materials that would cause uneven settlement.
Beneath slabs a base course (4 “ thick mixture of gravel, crushed stone, sand, or crushed slag) should be provided.
See figure 21.3-12 on page 1079 for acceptable soils to use for fill
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Soil Testing
Identify the materials on the site Determine
Soil density Moisture Content Load-bearing capacity Shear Strength Plasticity index Analyze the gain size of soil particles
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Soil Types
Division Description Value as a foundation material
Gravel and Gravelly Soils
Well-graded;
Gravel-sand mixtures; little or no fines
Excellent to good
Sand and Sandy Soils
Silty sands, sand-silt mixtures
Fair
Silts and Clays Organic silt-clay of low plasticity
Poor to very poor
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Primary Soil Considerations: Dewatering-
Critical in sub-surface foundations (basement –earth sheltered)
Open-drain (French) & gravel used to lead water away
Pumps may also be used to remove excess water
Compaction – critical !! - to prevent uneven load settlement
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Soil Considerations con’t:
Stabilization – use various additives to adjust the properties of soil
Poisoning- used to control termites * Note: certain chemicals are no longer used due to environmental concerns
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Termite Control
Subterranean termites pose a great hazard to building materials – especially in mild climates
Termites live underground but build tubes of earth to reach wood, fiberboard, fabrics, and paper. They must have a constant source of water or they will die
They enter a structure by attacking wood in contact with the ground, through small cracks, or by flying.
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Soil Poisoning
Because of environmental concerns many chemicals are no longer used for this
Acceptable termiticides include: Chlorpyrifos Cypermethrin Fenvalerate Isofenphos Permethrin
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Surface & Groundwater Surface water – most problems with this arise
from improper grading Slabs on grade – problems may be eliminated
by proper grading, selecting correct base materials, and installation of a vapor retarder
Vapor Retarder – this membrane should resist deterioration, be thick enough to resist penetration (usually 6 mils), and be overlapped 6 inches during installation Common material used is polyethelene
sheeting
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Paving & Surfacing
Different materials are used to perform each Paving – uses concrete, stone, or brick Surfacing – uses flexible and water-
bound surfaces
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Asphalt Is a dark-brown to black, solid or semi-
solid, mainly composed of Bitumens (a tarry mixture of hydrocarbons) Bitumens also used in:
Water proofing coatings Sheet Water proofing Damp proofing below grade
Asphalt moves into a liquid state when heated
Coal Tar Pitch – greater water resistance than asphalt, good adhesive properties, unlike asphalt - contains very little bitumen
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References Construction Materials and Processes, 3rd Edition. Watson, Don A..
McGraw-Hill, 1986. Imprint 2000. ISBN: 0-07-068476-6 Construction Principles, Materials, and Methods, Seventh Edition. H.
Leslie Simmons, John Wiley and Sons, Inc., 2001. Olin’s Construction Principles, Materials, and Methods, Eighth Edition.
H. Leslie Simmons, John Wiley and Sons, Inc., 2007. Architectural Materials for Construction, Rosen, Harold J. and
Heineman, Tom. McGraw-Hill, 1996. ISBN: 0-07-053741-0 Basic Construction Materials, 6th Edition. Marotta, Theodore W.
Prentice Hall, 2002. ISBN: 0-13-089625-X Building Construction: Materials and Types of Construction, 6th Edition,
Ellison, Donald C., Huntington, W.C., Mickadeit, Robert E.. John Wiley & Sons. ISBN: 0-13-090952-1.
Architectural Graphic Standards: Student Edition, Abridgment of 9th Edition. The American Institute of Architects. John Wiley & Sons. ISBN: 0-471-34817-1
