21
On an absolutely rigid foundation base, the pressure will
Answer & Solution
Answer: Option
B
Solution:
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.
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.