What is liquefaction?
Liquefaction is a phenomenon that occurs when soil or other granular materials lose their strength and stiffness due to an increase in pore water pressure caused by an external force, such as an earthquake or other rapid loading event. It results in the transformation of solid soil into a liquid-like state, reducing its ability to support structures and causing potential damage to buildings, infrastructure, and other structures.
During liquefaction, the soil particles become suspended in the water-filled spaces between them, and the soil loses its ability to resist shear stresses. As a result, the soil behaves like a fluid, and structures built on or in the liquefied soil may sink, tilt, or even collapse.
Liquefaction is most commonly associated with saturated loose, granular soils, such as sand and silt, that are subjected to rapid and cyclic loading, such as shaking during an earthquake. The shaking causes an increase in pore water pressure in the soil, reducing the effective stress and causing the soil to lose its strength and stiffness.
Liquefaction can have severe consequences, including damage to buildings, infrastructure, and underground utilities, as well as potential loss of life. It is a significant geotechnical engineering challenge and is taken into consideration in the design and construction of structures in earthquake-prone regions. Techniques such as densification of loose soils, improving drainage, and using deep foundations are often employed to mitigate the risk of liquefaction-induced damage in vulnerable areas.