Seismic Response and Liquefaction of a Large Sand Specimen on Shaking Table

Seismic Response and Liquefaction of a Large Sand Specimen on Shaking Table

A physical model test using a large biaxial laminar shear box on the shaking table at the National Center for Research on Earthquake Engineering(NCREE), Taiwan was conducted to study the seismic responses of the saturated sand under multidirectional earthquake shakings. Pore pressures and accelerations within the soil, and the displacements and accelerations of the frames at various depths were measured during tests under both one-and multi-directional shakings of various amplitudes. It is found that the excess pore water pressures generated during a two-dimensional shaking are substantially higher than those generated under the one-dimensional shaking of the same magnitude of acceleration. The settlement of the sand inside the shear box after each shaking test was also measured and evaluated. The test results showed that significant settlements occurred only when there is liquefaction of the soil and the volumetric strain of the liquefied sand decreases with the relative density of sand.