CIVL 361Earthwork

Dr. Mehmet M. KuntFall 2009

EMU

Earthwork

• Always Transportation Construction Projects involve earthwork

• Objective is usually the minimization of earthwork

Earthwork Cross-Sections

Example Cut and Fill

EMBANKMENT(FILL)

EXCAVATION (CUT)

6

Terrain Effects on Route Location

• Don’t forget your design criteria (grades, etc)

• Attempt to minimize amount of earthwork necessary– Set grade line as close as

possible to natural ground level– Set grade line so there is a

balance between excavated volume and volume of embankment

http://www.agtek.com/highway.htm

Earthwork Cross-Sections

Cut-excavationFill-embankment

Slopes:<45° vertical component is unitary 1:2>45° horizontal component is unitary 5:1Note: Cut and fill slopes are always flatterthan 1:1

Cross-Section Data Format

Cross-Section

Cross-Section

Cross-Section Area Example

Cross-Section Area Example

Cross-Section Area

Cross-Section Area

Ref: IGRDS Chapter-7

Ref: IGRDS Chapter-7

Area Calculation

Area Calculation

Area Calculation

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

Area Calculation

In this formula, W is the width of the highway; hl and hr, are the vertical distances of the left and right slope stakes above grade; dl and dr are the center-line distances of the left and right slope stakes; and C is the depth of the center-line cut or fill. Applying the formula for station 305 + 00, youget the following results:

A = (40/4)(8.2+ 12.3)+ (9.3/2)(29.8+ 35.3)= 507.71 square feet.

28

Earthwork Analysis

• Take cross-sections (typically 25 m)

• Plot natural ground level

• Plot proposed grade profile

• Indicate areas of cut and fill

• Calculate volume between cross-sections

Earthwork Quantities

Earthwork computations involve:

• Calculation of earthwork volumes

• Balancing of cuts and fills• Planning of the most

economical material hauls.

30

Shrinkage

• Material volume increases during excavation

• Decreases during compaction

• Varies with – soil type

– fill height

– cut depth

31

Swell

• Excavated rock used in embankment occupies more space

• May amount to 30% or more

• Shrinkage factors of 15 to 20% and a bulkage factor of 25%

Ref: Florida Department of Transportation

Summary of Final Report, WPI# 0510796

January 1999

Mass DiagramEarthmoving is basically an operation where material is removed from high spots and deposited in low spots with the “making up”of any deficit with borrow or the wasting of excess cut material.

Mass DiagramThe mass diagram is an excellent method of analyzing linear earthmoving operations.

It is a graphical means for measuring haul distance (stations) in terms of earthwork volume (cubic yards).

Mass Diagram

Aids in identifying:

• Where to utilize specific types of equipment,

• Where quantities of material are required,

• Average haul distance,

• Haul grades.

Earthwork

The horizontal dimensions of a project are dimensioned in stations. One station equals 100m.

100m

.

0+00

1+00

43

Special Terms• Free haul distance (FHD)- distance earth is moved without

additional compensation • Limit of Profitable Haul (LPH) - distance beyond which it is

more economical to borrow or waste than to haul from the project

• Overhaul – volume of material (Y) moved X Stations beyond Free haul, measured in sta–yd3 or sta-m3

• Borrow – material taken from outside of project• Waste – excavated material not used in project

Ref: http://www.globalsecurity.org/military/library/policy/army/fm/5-430-00-1/CH3.htm

Ref: http://www.globalsecurity.org/military/library/policy/army/fm/5-430-00-1/CH3.htm

Ref: http://www.globalsecurity.org/military/library/policy/army/fm/5-430-00-1/CH3.htm

Ref: http://www.globalsecurity.org/military/library/policy/army/fm/5-430-00-1/CH3.htm

50Source: Wright 1996

Between Stations 0 + 00 and 0 + 132, cut and fill equal each other, distance is less than FHD of 200 m

Note: definitely NOT to scale!

51Source: Wright, 1996

Between Stations 0 + 132 and 0 + 907, cut and fill equal each other, but distance is greater than either FHD of 200 m or LPH of 725 mDistance = [0 + 907] – [0 + 132] = 775 m

52Source: Wright, 1996

Between Stations 0 + 179 and 0 + 379, cut and fill equal each other, distance = FHD of 200 m Treated as freehaul

53Source: Wright, 1996

Between Stations 0 + 142 and 0 + 867, cut and fill equal each other, distance = LPH of 725 m

54Source: Wright, 1996

Material between Stations 0 + 132 and 0 + 142 becomes waste and material between stations 0 + 867 and 0 +907 becomes borrow

55Source: Wright, 1996

Between Stations 0 + 970 and 1 + 170, cut and fill equal each other, distance = FHD of 200 m

56Source: Wright, 1996

Between Stations 0 + 960 and 1 + 250, cut and fill equal each other, distance is less than LPH of 725 m

57Source: Wright, 1996

Project ends at Station 1 + 250, an additional 1200 m3 of borrow is required

Example Cut and FillAs material is moved from the excavation

to the compacted fill the only factor that is constant is the weight of the solid particles (γγγγd).