How to Calculate Volume of Trapezoidal Footing

Trapezoidal Footing includes = Truncated Pyramid + Cuboid

Assume a Trapezoidal Footing with dimensions 2 m by 1.5 m [length = 2 m and breadth = 1.5 m] and height is equal to 300 mm.

Volume of Rectangular Cuboid = Length x Breadth x Height

Volume of Truncated pyramid = 1/3(A₁ + A₂ + √A1A2)h

Here, A₁ = Top Base Area

A₂ = Bottom Base Area

A₁ = 0.5 x 0.4 = 0.2 m²

A₂ = 2 x 1.5 = 3 m²

h = height = 0.3 m

Putting the quantities in the formula, we get

Trapezoidal Footing Volume = Truncated Footing Volume + Cuboid Volume

= (Length x Breadth X Height) + 1/3(A₁ + A₂ + √A1A2)h

= (2 x 1.5 x 3) + 1/3(0.2 + 3 + √(0.2 x 3)) x 0.3

= 0.9 + 0.397 = 1.297 m³

For more information, go through the following tutorial.