review - earth work fall 2011. steps for earth work computation define typical cross section apply...
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REVIEW - EARTH WORK
Fall 2011
STEPS FOR EARTH WORK COMPUTATION
Define Typical Cross Section
Apply Typical Cross Section:
Every Station
Station at pluses (ground breaks)
PT and PC
Where profile change from cut to fill or vise versa
Compute Area for each Cross Section
Compute Volumes between Cross Section
Typical Cross Section
Harbin (1998) Figure 20.2
Application of Typical Cross Section
Wright and Dixon (2004) Fig 13-5
Application of Typical Cross Section
Sections at Pluses
Harbin (1998) Figure 20.3
Application of Typical Cross Section
Harbin (1998) Figure 20.4
Transition
Excavation & Grading Handbook (http://www.electrical-contractor.net/The_Store/CR/Exc&Grading_Hbk_Preview.htm)
Side Slope
Plotting Cross Sections
Harbin (1998) Figure 20.6
Computing Areas for Cross Sections
McCormack (1985) Figure 13-3
Computing Areas for Cross Sections
McCormack (1985) Figure 13-3
Computing Volumes
1 21 2
27
L A AV
Average-End-Area
Where,V = volume (cu yd)A = area end sections (ft3)L = distance between end
sections (ft)
1 21 2V L A A
Where,V = volume (m3)A = area end sections (m2)L = distance between end
sections (m)
U.S. Units
Metric
Note: 1 yd3 = 27 ft3
Computing Volume - Example
Determine the earthwork volume between Stations 100 and 101 using the average area method if the road width is 30 ft. The cut side slopes are 2 : 1.
Station Left Center Right
100+00 C8.031.0
C6.00.0
C5.025.0
101+00 C6.027.0
C4.00.0
C2.019.0
Computing Volume - Example
Determine the earthwork volume between Stations 100 and 101 using the average area method if the road width is 30 ft. The cut side slopes are 2 : 1.
Cross Section at 100+00
Computing Volume - Example
Determine the earthwork volume between Stations 100 and 101 using the average area method if the road width is 30 ft. The cut side slopes are 2 : 1.
Area at Station 100+00
1
1
21
4 230 6.08.0 5.0 31.0 25.0
4 2
265.5
L R L R
w cA h h d d
A
A ft
Computing Volume - Example
Determine the earthwork volume between Stations 100 and 101 using the average area method if the road width is 30 ft. The cut side slopes are 2 : 1.
Area at Station 101+00
2
22
30 4.06.0 2.0 27.0 19.0
4 2
152.0
A
A ft
Volume between 100+00 and 101+00
1 2
3
1 2
270.5 100 (265.5 152.0)
773.127
L A AV
V yd