Question

In case of coarse grained sand having high permeability and low plasticity, 95% of consolidation occurs within ______ after application of load.
1. 1 minute
2. 30 minute
3. 1 hour
4. 2 hour

Answer 1

Correct Answer - Option 1 : 1 minute

Explanation:

The compression of saturated soil under steady static pressure is termed consolidation which is completely due to the expulsion of water from the voids.

Note:

• Consolidation is generally related to fine-grained soils such as silts and clays.
• Coarse-grained soils, such as sands and gravels, also undergo consolidation but at a much faster rate due to their high permeability and low plasticity.
• In sands and gravels, 95 % of consolidation occurs within 1 min after application of load.
• Saturated clays consolidate at a much slower rate due to their low permeability.

The consolidation of soil is divided into three stages:

1. Initial consolidation

2. Primary consolidation, and

3. Secondary consolidation.

The consolidation of soil is time-dependent and its analysis is usually based on Terzaghi’s theory.