Trapezoidal Footing Calculation Process

By going through this exclusive civil engineering tutorial, you will learn the process for working out the quantity of trapezoidal footing.

Dimension of the top view of footing :-Length = 2.5 meter, Breadth = 2 meter

The dimension of the small square portion of top is given as follow :-

Length = 400 mm
Breadth = 300 mm

The height of the square at lower portion is taken as 200 mm or 0.2 m and the height at upper portion is taken as 400 mm or 0.4 m.

The area of lower portion is represented as A1

The area of top portion is represented as A2

Initially, you have to find out the volume of rectangle as follow :-
= Length X Breadth x Height
= 2.5 x 2 x 0.2 = 1m³ or 1 cubic meter

Now, you have to find out the volume of trapezoid with the following formula :-
= 1/3 (A1 + A2 + (√A1 + A2)H

Also Read: How to calculate the volume of concrete in a trapezoidal footing

Area of bottom portion (A1)= L x B = 2.5 x 2 = 5m²

Area of top portion (A2) = L x B = 0.4 x 0.3 = 0.12m²

Now, you have to put the above valued in the formula :-

1/3 (5+0.12+√5 x 0.12)0.4

= 0.785 m³

Now, add volume of rectangle & trapezoid.

= 1 + 0.785 = 1.785 m³

Thus, the quantity of trapezoidal footing is 1.785 m³

Video Source: Civil Engineering