Question

Find the amount of earthwork from the mid-sectional area method, assuming there is no transverse slope, while the elevations at both the ends of the land with the same slope are 1 m and 1.6 m respectively, the width and length of the road is 10 m and 200 m respectively and the side slope is 2: 1.
1. 3276 Cu. m
2. 3300 Cu. m
3. 3288 Cu. m
4. 3312 Cu. m

Answer 1

Correct Answer - Option 1 : 3276 Cu. m

Concept:

The formula used for finding the amount of earthwork using mid-sectional method is given by:

V = A x L 

where,

V= Volume of earthwork

A = Area of mid-section = BDm + SDm2 

B = Width of road

D_m = Depth at mid-section = \((D1 + D2) \over2\)

S = Slope

L = Length of road

Calculation:

Given data:

D₁ = 1 m

D₂ = 1.6 m

L = 200 m

B = 10 m

S = 2

So, D_m = \((1 + 1.6) \over 2\) = 1.3 m

Now, 

A = (10 x 1.3) + (2 x 1.3²) = 16.38 m²

Now, 

V = 16.38 x 200 = 3276 m³