What phenomenon refers to the reduction of strength and stiffness in soil due to earthquake shaking or rapid loading?

Liquefaction refers to the phenomenon where soil loses its strength and stiffness due to shaking from an earthquake or rapid loading. During an earthquake, the stress exerted on the soil can cause the pore water pressure within the soil’s voids to increase, leading to a condition where the soil behaves like a fluid. This transition can result in significant ground deformation, which can severely impact structures and infrastructure built on or within the affected soil.

Understanding liquefaction is critical for geotechnical engineering, especially in seismic design, as it can lead to catastrophic failures if not properly addressed. In contrast, other terms such as lateral spreading, settlement, and consolidation refer to different geotechnical reactions and behaviors under various conditions, but they do not specifically describe the loss of strength due to seismic activity.