1 site work. 2 major topics site plans earthwork soil foundations and piles paving and surfacing...
TRANSCRIPT
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Site Work
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Major Topics
Site Plans Earthwork Soil Foundations and Piles 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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Earthwork
Involves some type of cut or fill This phase of site work is referred
to as “rough grading” Soil testing is usually performed
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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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Foundations and Piles Foundation
Any part of the building that is below the surface of the ground
Provides stability to the entire structure Type of foundation used is determined
by: Soil present at site Total load must be determined (live &
dead loads) Local building codes must be referenced
to determine allowable type & bearing pressure
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3 Parts of Foundation:
Bed – the rock or soil the foundation rests upon
Footing – wide section of foundation resting on bed
Wall – rises from footing to above the ground (may also be a column or pedestal)
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Common Types of Residential Foundations :
Continuous Composed of a foundation wall & footing
slab Size of footing & thickness of wall
determined by building codes Grade-Beam
Composed of reinforced concrete beam around perimeter which is supported by concrete piers
Often used on sloping sites
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Others Foundations: Spread
Distribute the load so the load per sq. ft. will not exceed the bearing capacity of soil
May be flat, stepped, or sloped in design Mat
Heavily reinforced concrete slab under entire building
Sometimes called a “floating foundation” Caissons
Used when rock or suitable soil is deep below the surface
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Piles
Slender structural unit which transmits loads underground
Types include Wood (Venice) Structural Steel H Pre-cast Concrete Cast-in-place Concrete Composite (combines wood &
concrete)
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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