Experimental investigation on liquefaction and post-liquefaction deformation of stratified saturated sand under cyclic loading

The soils are often distributed in a stratified structure. When an earthquake occurs, there are always risks of liquefaction for stratified soils which can cause serious consequences. The research aims to investigate the liquefaction and post-liquefaction deformation of saturated sand with stratified structure. The influences of liquefaction and post-liquefaction deformation were analyzed by varying the thickness, position, and layers of powdery sands. The findings showed that the correlations between the times taken to reach liquefaction for cyclic loading and the thicknesses of the powdery sandy interlayer are non-linear. With the optimal thickness, the powdery sand interlayer can effectively prevent the transfer of power water pressure. And two-layer powdery interlayer in the sample was more favorable to resist pore water pressure than that with single layer. The strength of post-liquefaction deformation and failure patterns are closely related to the distribution of powdery layer. The work provides new research evidence on the liquefaction and failure mechanism of saturated sands with stratified structure under cyclic loading which often happen during earthquakes