If the length of a combined footing for two columns l metres apart is L and the projection on the left side of the exterior column is x, then the projection y on the right side of the exterior column, in order to have a uniformly distributed load, is (where is the distance of centre of gravity of column loads).
A)y = L - (l - )
B)y = L/2 + (l - )
C)y = L/2 - (l + )
D)y = L/2 - (l - )

Question

Quizplus · Accepted Answer

For a combined footing to have a uniformly distributed load, the center of gravity of the system must align with the geometric center of the footing. The projection y on the right side can be found by considering the symmetry and balance of the system. The correct formula is y = L/2 - (l - ), which accounts for the distance from the center of the footing to the exterior column, adjusted by the distance of the center of gravity of the column loads from the midpoint between the columns.

If the Length of a Combined Footing for Two Columns