Examveda

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

Answer: Option B

Solution (By Examveda Team)

On an absolutely rigid foundation base: The pressure distribution is uniform because the foundation remains undeformed under the applied load.

Detailed Reasoning:

1. Definition of a Rigid Foundation:
A rigid foundation is an idealized structure that does not bend, flex, or deform when subjected to loads. It is assumed to transfer the applied load uniformly to the underlying soil or base material.

2. Uniform Pressure Distribution:
When a rigid foundation is placed on a base, the rigidity ensures that every point along the base moves together as a single unit. As a result, the pressure is distributed evenly across the foundation area. This uniformity occurs because there is no differential settlement or bending that would otherwise alter the pressure distribution.

3. Practical Assumption:
The concept of uniform pressure on a rigid foundation is an idealization used in structural design. It simplifies analysis and is valid when the subsoil is homogenous, and the load is symmetrical. Deviations from this condition can cause non-uniform pressures, but these are generally analyzed using more complex methods.

4. Contrast with Flexible Foundations:
In flexible foundations, deformation or bending occurs due to the applied load. This deformation causes variations in pressure, often leading to higher pressures at certain points, such as the edges or the center, depending on the load distribution and soil properties.

Key Assumption: The uniform pressure distribution is based on the idealization that the foundation is perfectly rigid and the soil is homogenous and linearly elastic.

This Question Belongs to Civil Engineering >> RCC Structures Design

Join The Discussion

Comments (1)

  1. Amir Zada
    Amir Zada:
    11 months ago

    In rigid footing settlement will be uniform and the pressure will varies and it depends upon the types of soil beneath the Footing .

Related Questions on RCC Structures Design

If the shear stress in a R.C.C. beam is

A. Equal or less than 5 kg/cm2, no shear reinforcement is provided

B. Greater than 4 kg/cm2, but less than 20 kg/cm2, shear reinforcement is provided

C. Greater than 20 kg/cm2, the size of the section is changed

D. All the above