Chapter 4

Measuring Sitework, Excavation, and Piling

Objectives• Upon completion of this chapter,

you will be able to:– Determine the likely soil conditions at

a site by studying a soils report– Explain the use of swell factor and

compaction factor when calculating volumes of excavation and backfill

Objectives (cont’d.)– Define bank measure and explain

how it applies to sitework takeoffs– Describe and use the “grid method”

of calculating cut and fill volumes– Describe and use the “section

method” of calculating cut and fill volumes

– Explain how piling work is measured in a takeoff

Objectives (cont’d.)– Explain how trenches and basements

are measured in a takeoff– Complete a manual takeoff of

sitework– Complete a computer takeoff of

sitework using Excel spreadsheets and MC2 ICE software

Generally• Measuring sitework and excavation

work – Different from measuring most other

work• Current site condition may not be provided• Dimensions and shape of excavations may

not be disclosed

– Estimators must assess requirements before measuring site work

Soils Report• Provides subsurface condition

information– Usually not a bid document– Includes data for foundation system

design

• Comments on sample soils report– Topsoil, moisture content, soil

compaction, slope ratio, drainage, etc.

Bank Measure, Swell, and Compaction Factors

• Extracted soil – Less dense and will occupy more

space

• Compaction factor– Difference between hole volume and

fill material volume

• Bank measure– Obtained using hole dimensions

Excavation Safety Considerations

• Potential danger to workers– Cave-ins

• OSHA’s Construction Safety and Health Regulations– Requires shoring systems or cutting

back sides to a safe angle• Strongly enforced

Use of Digitizers• Electronic devices

– Enables user to take measurements from drawings • Input directly into computer program

• Digitizer types– Sonic– Tablet

On-Screen Takeoff• Eliminates need for paper-based

printouts– Number of formats– Cost savings– Speed– Convenience

• Plans still have to be drawn to scale

Measuring Notes—Excavation and Backfill

• Include:– Measure in cubic yards or cubic

meters “bank measure”– Classify and measure separately

• Excavations• Materials• Hand excavation• Disposal of surplus soil

Calculation of Cut and Fill Using the “Grid Method”

• Requires a site survey – Showing elevation of existing grade

• Each intersection point on the grid• Plotted at each intersection point• Depth of cut can be obtained at each

point

– Refer to Figures 4.1 and 4.2 • Accuracy depends on grid spacing

Calculation of Cut and Fill Using the Section Method”

• Mostly used with long, relatively narrow areas of cut and fill– Road and railroad construction

• Results quality depends on accuracy of plotting– Refer to Figure 4.3

Trench Excavations• Formula for trench volume:

– Trench Volume = Length of Trench Centerline × Average Width of Trench × Average Depth of Trench

– Refer to Figure 4.4

• Sides of trenches often cut-back due to:– Safety reasons– Soil will not stand vertically

Trench Backfill• Volume of backfill for a trench

– Generally equal to volume of excavation minus volume of what is to be contained

– Surplus occurs when volume of excavation exceeds amount required for backfill• Item for disposal of surplus material is

required

Greater Accuracy• Formula used to calculate volume

of excavation:– Usually sufficient– Some situations require more

accuracy• Example: pit and basement excavations

Measuring Notes—Piling• Often subcontracted to specialized

companies• Typical general contractor items:

– Layout of piles– Cutting off tops of piles– Removing excavated material

Bearing Piles• Generally:

– Measure in linear feet or meters– Include a separate lump-sum item for

equipment– Piles that are measures separately– Measurement may be subdivided– Enumerate splicing and lengthening

of piles

Bearing Piles (cont’d.)• Additional considerations:

– Classification of bearing piles– Timber piles– Steel piles– Precast concrete piles– Poured-in-place concrete piles

Sheet Piling• Generally:

– Described and measured in square feet or square meters

– Separately measure piles– Measurement may be subdivided– Measure withdrawing of piles– Cutting off of sheet piling: measured

in linear feet or meters

Sheet Piling (cont’d.)– Splices: described and measured by

number– Timber sheet piling, concrete sheet

piling, and steel sheet piling: measured according to foregoing principles

– Extraction of piles: measured separately

Additional Examples • Drawings

– Refer to Figures 4.11 and 4.12

• Sitework takeoff– Example 1—The House Project

• Takeoff Shown as Figure 4.6a

– Example 2—The Office/Warehouse Project• Takeoff Shown in Figure 4.14a

– Sitework Takeoff Using ICE Software

Summary• The estimator has to make an

assessment of sitework requirements– Based on plans and specifications

• Site visit • Soils report

– Efficiency can be increased using a digitizer

– Sitework takeoffs can be done manually or via computer