At the point when a soil mass is subjected to the compressive force, its volume diminishes. The property of the dirt because of which a decline in volume happens under compressive constrain is known as the compressibility of soil. This compressibility of soil can happen due to
- Compaction of strong particles and water in the hollows
- Compression and removal of air in the voids
- Removal of water in the voids
The pressure of immersed soil under a consistent static weight is known as union. It is completely because of ejection of water from the voids
Initial, primary & secondary consolidation
- Initial consolidation: At the point when the load is coupled to an in part immersed soil, abatement in volume happens because of ejection and pressure of air in the voids. A little reduction in volume happens because of pressure of strong particles. The diminishment in volume of the dirt soon after the utilization of the heap is known as starting combination or introductory pressure. For soaked soils, the underlying combination is mostly because of pressure of strong particles.
- Primary Consolidation: After introductory consolidation, more volume diminish because of removal of water from the voids. At the point when an immersed soil is subjected to a weight, at first all the connected weight is taken up by water as an overabundance pore water weight. A pressure driven slope will create and the water begins streaming out and a reduction in volume happens. This decrease in volume is called as the primary consolidation of soil.
- Secondary Consolidation: The decrease in volume proceeds at a moderate rate even after the overabundance hydro-static weight created by the connected weight is completely dispersed and the essential consolidation is finished. The extra lessening in the volume is called as the secondary consolidation.