Average End Area

V = \frac{L}{2} (A_{1} + A_{2})

Prismoidal earthwork between two stations. L is the station interval (often 100 ft or 20–50 m). Cut and fill are tracked separately, then adjusted by shrinkage (fill) and swell (cut haul). Borrow and waste balance the mass diagram.

$A_{1}, A_{2}$ (m² or ft²): End areas
$L$ (m or ft): Distance between sections

Step-by-step solved example

Cut areas 40 m² and 64 m², 20 m apart. Volume of cut?

V = L (A1+A2)/2 between two cross sections.

1. Average end area
V = 20/2 × (40+64) = 10×104 = 1040 m³.
$V = 1040 m^{3}$

Answer: 1040 m³

10 practice questions

0/10 correct

1.If A1 = A2 = 50 m², L = 30 m, V =

2.Shrinkage of 10% means 100 bank m³ placed fill occupies about

3.Swell of 25% means 1 bank m³ in a truck is

4.A mass diagram plots

5.Freehaul is

6.Bank, loose, compacted relate through

7.Stations 3+00 to 3+50 (50 ft), areas 80 and 120 ft². V =

8.1 LCY (loose cubic yard) vs BCY

9.Prismoidal correction is needed when

10.A fill factor of 0.8 on a 12 yd³ bucket yields