Influence of a non-free field subsurface seismic history on the liquefaction resistance of sandy soils
摘要
Seismic-induced liquefaction of sandy soils can fail foundations in the vicinity of buildings. To investigate the effect of a non-free field subsurface seismic history on the ability of saturated sandy soils to resist liquefaction, four shaking events with different accelerations were input to the sandy soils in the non-free-field. The results of the study revealed that: (1) Shallow soils that are not free-field undergo acceleration amplification effects after being subjected to seismic loading. (2) Building overburden pressure reduces the sensitivity of the shallow soils directly below in small and moderate earthquakes, which are more prone to rearranging and forming unstable structures under strong seismic effects. The excess pore pressure response on the load side resembles that of a free site, with the depth range of the liquefaction strength of soils affected by the seismic history, increasing progressively as input seismic intensity increases. (3) After experiencing earthquakes of different intensities, the excess pore pressure directly below the building overburden pressure at 0.1 m and 0.2 m is greater than that at the side. At the same time, the side of the building structure is more prone to liquefaction than the soil directly below it.