Procedure:
1. The total length of plane is divided into no of strips.
2. Calculate the areas at ends (A1&An)
3. Calculate area of intermediate strips A2,A3,A4…… An
So that,A1, A2, A3 ….An are areas of cross sections and D is the distance between consecutive sections.
4 Volume of earthwork is given as
V= D/3(A1+4A2+2A3+4A4+……….+2A(n-2)+4A(n-1)+An)
5 To use this formula it requires odd number of section.