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Road earthwork with RL of GL and FL (0-600)

Short answer

Cutting = 2410.45 m³, filling = 1875.00 m³. Level-gound areas (B+sh)h; volumes averaged between sections; filling-to-cutting transition split by depth ratio.

Calculate earthwork for the following section of road from the given data. i) Formation width = 8 m, ii) Side slope in filling and cutting = 2:1 and 1½:1 respectively.

Distance (m)0100200300400500600
RL of GL99.510099.8101.6102.3101.1103
RL of FL1001:200 (upward)1:400 (downward)

Given data and assumptions

  • Formation width B=8B = 8 m; side slope in filling 2:12:1, in cutting 1.5:11.5:1 (H:V). Ground is taken as level across the road (no cross slope given).
  • Formation level at 0 m is 100.00 m. The gradient is read as 1 in 200 upward from 0 to 300 m and 1 in 400 downward from 300 m to 600 m (the printed table shows only the two gradients).

Method

Level (plain-ground) sections are used. With centre height hh, formation width BB and side slope s:1s:1:

A=(B+s h) hA = (B + s\,h)\,h

Volume between two sections = mean area × distance; where a section changes from cutting to filling, the length of each part is found by proportion of the depths and the volume of each part = ½ × end area × length.

ChainageGL (m)FL (m)Depth of cutting / height of filling (m)
0+00099.500100.000filling 0.500
0+100100.000100.500filling 0.500
0+20099.800101.000filling 1.200
0+300101.600101.500cutting 0.100
0+400102.300101.250cutting 1.050
0+500101.100101.000cutting 0.100
0+600103.000100.750cutting 2.250

Sectional areas

ChainageCentre ht. hh (m)Cutting area (m²)Filling area (m²)
0+000fill 0.500.0004.500
0+100fill 0.500.0004.500
0+200fill 1.200.00012.480
0+300cut 0.100.8150.000
0+400cut 1.0510.0540.000
0+500cut 0.100.8150.000
0+600cut 2.2525.5940.000

Volumes

BetweenDistance (m)Cutting (m³)Filling (m³)
0+000 – 0+100100.00.00450.00
0+100 – 0+200100.00.00849.00
0+200 – 0+300100.03.13576.00
0+300 – 0+400100.0543.440.00
0+400 – 0+500100.0543.440.00
0+500 – 0+600100.01,320.440.00
Total600.02,410.451,875.00

Answer: Earthwork in cutting = 2,410.45 m³; earthwork in filling = 1,875.00 m³.

✓ Answer checked by Claude Opus 5.5 (high effort)

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