Test study on deformation characteristics of lightweight sand-EPS beads soil under dynamic load

Lightweight sand-EPS beads soil (LSES) is a novel lightweight geomaterial to improve soft ground by reducing vertical pressure on ground and improving the bearing capacity of ground. Because LSES is mainly used as subsoil, its deformation characteristics under dynamic load is worth to study. Based on laboratory cyclic triaxial test data, the effects of confining pressure, cement content, EPS content and number of loading cycles on the dynamic deformation characteristics of LSES are discussed. Under low confining pressure(sigma(c)=50 kPa), LSES shows linear dynamic stress-strain relationship similar with that of EPS block; while under relatively high confining pressure (sigma(c)=100,150 kPa), its fitting dynamic stress-strain curve is hyperbolic type. Under given strain, the dynamic secant elastic modulus (E-sec) of LSES increases with increasing confining pressure and cement content while decreases with increasing number of loading cycles; and E-sec-epsilon(d) curve is more smooth when EPS content increases.