What is a primary cause of soil liquefaction?

Soil liquefaction primarily occurs when applied stress from earthquakes induces a temporary loss of strength in saturated soil. During seismic shaking, the ground motion increases pore water pressure in the soil, reducing the effective stress and causing the soil to behave like a liquid. This phenomenon is particularly common in loose, saturated, and cohesionless soils such as sands, which can quickly lose their stability under such dynamic loading conditions.

While excessive moisture content can contribute to liquefaction, it is the applied stress from earthquakes that is the direct trigger in most cases. High temperatures and heavy traffic loads do not typically cause the sudden changes in pore pressure that lead to the rapid loss of soil strength observed in liquefaction scenarios. Thus, the seismic forces generated during an earthquake are the key factor that initiates the liquefaction process.