RCC Structures Design - Engineering

Q1:

On an absolutely rigid foundation base, the pressure will

A be more at the edges of the foundation

B be uniform

C not be uniform

D be zero at the centre of the foundation.

ANS:C - not be uniform

On an absolutely rigid foundation base, the pressure exerted by the foundation on the underlying soil would indeed not be uniform. Instead, it would be more concentrated at the edges of the foundation. This occurs because when a load is applied to a rigid foundation, the foundation cannot deform to distribute the load evenly across its entire base. As a result, the load is transmitted directly to the soil beneath the edges of the foundation, leading to higher pressure at those locations. This phenomenon is often referred to as "edge effect." In contrast, at the center of the foundation, the pressure would be relatively lower because the load is spread over a larger area compared to the edges. Therefore, the corrected explanation is: "On an absolutely rigid foundation base, the pressure exerted by the foundation on the underlying soil would not be uniform. Instead, it would be more concentrated at the edges of the foundation due to the inability of the rigid foundation to deform and distribute the load evenly across its entire base."