Abstract:In order to explain macroscopical deformation of saturated soft clay under subway load,the cyclic triaxial test,mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) are conducted and the correlatability between microstructure change and macroscopical deformation of saturated soft is analyzed.The mechanism and tendency of macroscopical deformation of saturated soft clay around tunnel under subway load are obtained,providing basis for predicting the subgrade subsidence due to subway load.