Essay 1-2 pages Cost & estimating
Ssult89
Lecture7-SITEWORKS-Excavation.pdf
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Site works-Excavation
Lecture 7
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Division 2 – Existing
Conditions
Surveys
Geotechnical Investigation
Site Demolition
Transportation and Disposal of Hazardous Materials
Asbestos Remediation
Lead Remediation
Mold Remediation
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BCN 5618 4
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Division 31 - Earthwork
Site Clearing
Earth Stripping & Stockpiling
Excavation and Fill
Erosion and Sedimentation Control
Dewatering
Excavation Support/Protection
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Earthwork
Specifications
Excess excavated materials (how far must it be hauled)
Clearing and grubbing (who is responsible?)
Topsoil (must it be stockpiled for future use? Where?)
Trenching for mechanical and electrical work (who is responsible for?)
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Type of Soil
Soil Borings
Visiting the site
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Calculating Excavation
Unit (cubic yard, 1 cy = 27 cf)
Swell and shrinkage
1.0 cy in natural condition (bank yard) = 1.25 cy after digging (loose yards) = 0.9 cy after compaction (compacted yards)
swell factor = loose yard/bank yard
shrinkage factor = compacted yard/bank yard
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Equipment
Minimize hand digging and shoveling
Select suitable equipment The bulldozer is suitable for moving soil for
short distances only up to about 150 ft.
Rubber-tired scrapes are excellent for earthmoving up to 1.5 miles.
Dump trucks are used for hauls beyond the economic range of rubber-tired scrapers.
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Equipment Selection
The sheeps foot roller is suitable for compacting very
cohesive soil in lifts of about 6 in or less.
Vibration is an excellent means of compacting sands,
and vibratory rollers are designed to use this method. It
is normally a steel wheel roller with an auxiliary device to
provide vibration to the roller.
Pneumatic tired rollers, impart a kneading action as well
as vertical pressure on the soil being compacted. They
are good for sands, gravels, or those materials in
combination with some cohesive material.
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New site grades and rough grading
Cutting and filling to reshape the grade
Cross Section Method
For building sites and parking areas
Dividing the site into a grid and determining the cut or fill for each of the grids
Average End Area
For long narrow tracts such as roads
The site is divided into stations
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Labeling Convention
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Fill Volume (Grid 13)
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Cut Volume (Grid 40)
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Cut and Fill (Grid 10)
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New site grades and rough grading
Cutting and filling to reshape the grade
Average End Area
For long narrow tracts such as roads.
The site is divided into stations;
a profile at each station line is drawn;
the cut or fill area of two adjacent profiles is averaged and multiplied by the distance between the two stations.
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Road Site Plan
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Cut Area Calculation
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Topsoil Removal
Unit (cubic yard)
Depth
Stockpile location
Clearance buildings: 5'
walks, roadways, and parking areas: 1' to 2'
Equipment: a bulldozer or a front-end loader
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General Excavation
Removal of all types of soil that can be handled in fairly large quantities using power equipment (basement, cut for a highway, ..)
Add 1' on all sides of the footing to allow workers to install and remove forms
Allow for the sloping of the banks (angle of repose)
What must be done with the excess excavation?
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Typical Excavation
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Special Excavation
Portions of the work that require hand excavation or special equipment other than general excavation (footing holes, small trenches)
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Backfilling
Volume of excavation minus volume of the building within the area of excavation.
Tamping or compaction is required
Soil shrinkage must be considered
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Backfill Section
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Excess and Borrow
If volume of cut > volume of fill, excess materials must be disposed of
If volume of fill > volume of cut, shortage materials must be borrowed
Topsoil is not included in this comparison.
Consider soil swell for excess materials
Determine the distance excess materials must be hauled away
Consider shrinkage for borrowed materials
BCN 5618 34
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BCN 5618 35
BCN 5618 36
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Division 32 – Exterior
Improvements
Base Course
Flexible Paving
Rigid Paving
Landscaping
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Spreading Topsoil, Finish
Grade
Stockpiled topsoil is usually placed over the rough grade to make it a finish grade. If the volume is not sufficient, it will have to be purchased.
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Asphalt Paving
Unit (SY or Ton)
Determine the surface area to be paved (SF)
Determine the compacted thickness of each course and type of materials required (inches)
Use the following table to find the tonnage of asphalt, granular materials, and subgrade materials.
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Landscaping
Seeding and fertilizing (type, no. of # per square, area to be covered)
Sodding (type, area to be filled)
Trees and shrubs (number, size, and species)
Maintenance of landscaping and guarantee period
