关键词: 深埋砂层, 地震动, 动力离心模型试验, 液化, 超静孔隙水压力

Abstract: In discrimination experience, seismic liquefaction typically occurs within the depth range of 10-20 meters in sand layers. In this study we explore whether seismic liquefaction occurs in sand layers of 30-40 meters depth via centrifugal vibration test. The overlying soil layer is simulated through the accumulation of high-density steel balls. By conducting centrifuge shaking table tests, we investigate the pore water pressure development within a 12.8-meter thick sand layer buried at depths of 15 and 25 meters, respectively, under seismic action, and subsequently assess the liquefaction susceptibility. Results reveal that the excess pore water pressure ratio in the sand remains well below 1 at both burial depths, indicating no liquefaction occurrence. Comparatively, initial pore water pressure and excess pore water pressure increase gradually with greater overburden thickness. However, the excess pore water pressure ratio diminishes with increased overburden thickness. This trend suggests that the increase of buried depth of sand layer can obviously improve liguefaction resistance.

Key words: deep buried sandy layer, seismic wave, dynamic centrifuge test, liquefaction, deep buried, excess pore water pressure