Dynamic Shear Strength Characteristics of Lightweight Sand-EPS Soil

Abstract

Lightweight sand–EPS soil (LSES) is regarded as a kind of sustainable geomaterial for providing a way to reutilize fast-growing waste expanded polystyrene (EPS) packages. It is usually applied in marine geotechnical engineering to solve the excessive settling of soft ground or bumps at bridge heads due to its merits such as low density, high strength, and adjustability. Aiming to investigate the dynamic shear strength of LSES made from marine sand, a series of laboratory dynamic triaxial experiments was conducted on LSES with different proportions and control sand (CS). The influences of cement content, EPS bead content, and confining pressure on dynamic shear strength were analyzed, as were comparisons with the material sand. It was found that the dynamic strength of LSES increased with the increase in cement content and confining pressure. The bonding function of cement hydration products contributed to the dynamic strength of LSES; however, the work required a certain content of cement. The dynamic strength of LSES decreased with the increase in EPS bead content due to the low particle strength and smooth surface of EPS beads. The cyclic number of failure (Nf) of both LSES and CS decreased linearly with the increase in dynamic shear stress in semilogarithmic coordinates. Both the slopes and the intercepts increased with the increase in cement content and confining pressure. However, they decreased with the increase in EPS bead content.