CONSOLIDATION OF SOIL

Consolidation is a process by which soils decrease in volume. According to Karl von Terzaghi “consolidation is any process which involves a decrease in water content of saturated soil without replacement of water by air.”

difference b/w consolidation and compaction:

When stress is applied that causes decrease in volume of soil mass due to water (or other liquid) then consolidation, not compaction, has occurred.

primary consolidation:

The reduction in volume of a soil mass caused by the application of a sustained load on the mass; principally due to the squeezing out of water from the voids in the mass, accompanied by a transfer of the load from the soil water to the soil solids is called primary consolidation.

secondary consolidation:

Secondary compression is the compression of soil that takes place after primary consolidation In sand, it is mainly due to plastic readjustment in the soil mass ,settlement caused by secondary compression is negligible.

Normally Consolidated Soil : A soil that has never experienced a vertical effective stress that was greater than its present vertical effective stress is called a normally consolidated (NC) soil.

Over consolidated Soil : A soil that has experienced a vertical effective stress that was greater than its present vertical effective stress is called an over consolidated (OC) soil.

.