04 Earthwork Calculations Spring 2012 - Dadi

7/27/2019 04 Earthwork Calculations Spring 2012 - Dadi

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CE403Construction Methodology

Earthwork

Volume

Calculations


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Construction Methodology2

Three Views Presented in ContractDocuments to Show EarthworkConstruction Features

1. Plan View


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Three Views Presented in ContractDocuments to Show EarthworkConstruction Features

2. Profile

View


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Earthwork Volume Calculations

Cross Sectional Methods

Trench Excavations Average End Method

Plan Area Methods

Four Corner Method


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Trench Excavations

Volume = Cross Sectional Area X Length of Trench

Eg. Find the volume (bank measure) of excavation

required for a trench 3 ft (0.92 m) wide, 6 ft (1.8m)

deep, and 500 ft (152 m) long. Assume that the trench

sides will be approximately vertical

Solution:

X-section area: 3x6 = 18 sf

Volume: 18x500/27 = 333 BCY


7/33Construction Methodology7

A1

A2

L

Average End Method

CYft27.0VF

A&AbetweenLengthL

SectionsAdjacentTwoofAreaA,A

2

AA

VF

LCFVolume,

3

21

21

21



Reminder



Average End Area Method Example

Calculate the area between two

end areas, 100 ft apart.



Average End Method



A1

A3

A2

L

L

Average

End Method


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2

A...AA

2

A

VF

LV

:GeneralIn

2

AA

VF

L

2

AA

VF

LVolume

n

32

1

n

3221

Average End Method

A1

A3

A2

L

L



Average End Area Example 2

Station End Area (sf) Distance (ft) Volume (cy)

150+00 360

151+00 10,200 100

152+00 18,000 100

153+00 23,500 100

154+00 12,600 100

155+00 5,940 100156+00 400 100

Total Volume

R ll




From 150+00 to 151+00:

volume = (100*1/2*(360+10200))/27 = 19,556 CY

From 151+00 to 152+00

volume = (100*1/2*(10200+18000))/27 = 52,222 CY

From 152+00 to 153+00

volume = (100*1/2*(18000+23500))/27 = 76,852 CY

And so on and so on.

2

A...AA

2

A

VF

LV

:Recall

n

32

1

n

R ll




Station End Area (sf) Distance (ft) Volume (cy)

150+00 360

151+00 10,200 100 19,556

152+00 18,000 100 52,222

153+00 23,500 100 76,852

154+00 12,600 100

155+00 5,940 100156+00 400 100

Total Volume

2

A...AA

2

A

VF

LV

:Recall

n

32

1

n

66,852

34,33311,741

261,556 cy



Earthwork Volume Calculations

Cross Sectional Methods

Trench Excavations Average End Method

Plan Area Methods

Four Corner Method


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Four Corner Method

FILLCUT

2

FILL

2

FILL

FILLCUT

2

CUT

2

CUT

FILL

CUT

HHVF4

HLV

HHVF4

HLV

ftCorners,atFILLofHeightsofH

ftCorners,atCUTofHeigthsofH

ftInterval,GridL


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Four Corner Method

100

100

499.9 500.2

499.8 500.2

Final Elev.

= 500( ) ( )

( ) ( )CY11.9=0.1392.6=

0.3+0.4

0.2+0.1

27.04

100=V

CY21.2=0.2392.6=0.3+0.4

0.2+0.2

27.04

100=V

22

FILL

22

CUT


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Grid Method

Volume is the area of

grid multiplied by the

difference between theexisting and the

proposed elevations.


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Grid Method

Volume by

Layers


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Contour

Method

UK Reservoir

Finish Elevations

Scale: 1= 40


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Contour Method

VF

I

2

A...AA

2

A

VF

I

2

AAV

CY

ft27.0FactorConversionVolumeVF

ft.Interval,ElevationContourI

ftn,ContourbyenclosedAreaA

CY.FILL,orCUTofVolumeV

n32

1n

1i

1ii

3

2n


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Contour

Method

UK Reservoir

Finish Elevations

Scale: 1= 40


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Mass Diagrams

Shows two curves:

A continuous curve representing

the profile of the existing grade.

A continuous curve representing

the accumulated volume of

earthwork plotted against the

linear profile of the roadway.

Tells Us:

Quantities of Materials to cut and

fill

Average Haul Distances

Types of Equipment that should

be considered


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Mass Diagrams - Definitions

Cut volume of excavation for a given cut

Fill volume of material to be added to anexisting terrain for a given fill

Waste volume of material that is required to

be hauled off site

Borrow volume of material that is required to

be brought on site.


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Mass Diagram

Cut

Fill

Borrow


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Mass Diagrams

Cut

Fill

A peak on the mass diagram


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Turning Points

Balanced

Points

pea o e ass d ag acurve represents a point wherethe earthwork changes fromcut to fill.

A valley (low point) on themass diagram curve

represents a point where theearthwork changes from fill tocut.

When a horizontal lineintersects the curve at two ormore points, the accumulated

volumes at these points areequal.


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The average

length of haul fora balanced

section.

The location and

amount of borrowand waste for the

project.

Borrow

Mass Diagrams


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