The foundation settlement caused by lowering of water level in fine grained soils is _______.

Question

Question

This question was previously asked in

RRB JE CE 22 Apr 2025 Shift 2 CBT 2 Official Paper

Answer 1

Explanation:

Consolidation refers to the gradual reduction in volume and settlement of a soil due to the expulsion of water from its pores under an applied load.
In the case of fine-grained soils (like clays), lowering the water level can cause the soil particles to settle further, leading to consolidation settlement.
Fine-grained soils have a high water retention capacity, and when the water level is lowered, the water pressure in the pores decreases, resulting in further compression of the soil over time.

Additional InformationElastic Compression

Elastic compression refers to the temporary deformation of a material when subjected to stress, where the material returns to its original shape once the stress is removed.
In soils, this refers to the immediate deformation caused by external loads, such as the weight of a structure.
Unlike consolidation, which is a time-dependent process involving the expulsion of water, elastic compression is instantaneous and reversible when the applied load is removed.

Erosion

Erosion is the process by which soil particles are worn away and removed from their original location due to the action of wind, water, or other natural forces.
It generally occurs in coarse-grained soils or near water bodies where the flow can transport particles.
Erosion doesn’t directly relate to settlement caused by the lowering of water levels in fine-grained soils. However, it can occur if water levels fluctuate rapidly or if the soil is disturbed by water movement.

Plastic Compression

Plastic compression refers to the permanent deformation of a material when subjected to a load beyond its elastic limit, causing it to change shape irreversibly.
In soil, this might occur in coarse-grained soils under extreme pressure but is not a time-dependent process like consolidation. It’s more typical in materials that do not return to their original shape after load removal.
Plastic compression doesn’t directly describe the process that occurs when water levels are lowered in fine-grained soils. It’s more relevant in soils subjected to extreme load conditions.