When applied stress, usually from an earthquake or other sudden loading, causes saturated soil to temporarily lose its strength and stiffness, a phenomenon known as soil liquefaction. The soil acts like a liquid because of this phenomenon. Some key details regarding soil liquefaction are as follows.
Saturated Soil: When soil particles are saturated—that is, when water fills the voids between them—liquefaction usually takes place. This is typical of sandy, loose soils.
Triggering Stress: The stress that triggers liquefaction is often an earthquake, but it can also be caused by other sources of rapid loading, such as blasting or pile driving.
Loss of Strength and Stiffness: The soil’s capacity to support loads is significantly reduced during liquefaction as a result of an increase in water pressure that keeps soil particles from coming into contact with one another.
Consequences: Severe ground deformation, such as lateral spreading, flow failures, and settlement, can be caused by a reduction in soil strength. Construction sites, bridges, automobiles, and other infrastructure can sustain significant damage as a result of these impacts.
Signs of Liquefaction: Evidence of past liquefaction includes features like sand boils, ground fissures, and lateral spreads.
How It Happens
Earthquake Shaking: The earth’s water pressure rises because of an earthquake’s shaking. An excessive increase in water pressure causes the soil’s solid structure to be lost as the particles are free to move around.
Pore Water Pressure: One crucial element is the accumulation of pore water pressure. Pressure rises as the water in the pores resists the compression caused by the soil particles trying to settle as a result of shaking.
Mitigation Measures:
Several ground improvement techniques can be used to lower the risk of liquefaction.
One such technique is soil compaction, which involves compacting the soil to lessen the likelihood of liquefaction.
Drainage: To decrease the pore water pressure and water table, drainage systems should be installed.
Reinforcement: Fortifying the soil with geosynthetics or other materials.
In order to avoid significant damage and guarantee the stability and safety of structures, it is essential to comprehend and mitigate soil liquefaction, particularly in areas that are prone to earthquakes.
