Soil liquefaction is a process in which, during earthquake or application of dynamic load, loose, saturated and cohesionless sand loses its all shear strength under the action of vibration caused due to earthquake or other reason.
Causes of liquefaction
- Soil must be cohesionless : If soil is cohesive then there will be some shear strength possessed by soil, which prevents liquefaction.
- Soil must be loose.
- Soil must be under dynamic stress. : If stress is static, pore water pressure may get enough time to dissipate.
- Soil must be in undrained condition.
Effects of soil liquefaction
- Structure may sunk into the soil, or say excessive settlement of structure may be observed.
- In some cases differential settlement may happen.
Mitigation of liquefaction
- Overburden pressure could be applied over the soil
- If possible, soil should be replaced by other cohesive soil.
- Stone column should be placed.
- Proper drainage should be provided.
- Addition of cohesive material could help to mitigate the effect of liquefaction.