Macro and micro analysis on deformation characteristics of fine sand under different groundwater table change

By using the samples of fine sand in Shanghai’s seventh layer, creep tests were performed to investigate deformation characteristics under different groundwater table change. It was revealed that is closely related change: when effective force caused by change smaller than pre-consolidation force, mainly elastic. When bigger compression large and rebound small; viscoelastic plastic equal stress. Through scanning electron microscope (SEM) analysis it found dominated slip particles, not breaking particles. And particles are squeezed load induced change, slide along indirect contact surface resulting continuous adjustment position relative displacement. Mercury injection test shows pore size distribution has little before after test.