Proportion-based constitutive model for sand-EPS beads lightweight fill

Abstract

Using indoor experiment, this paper investigated the stress-strain relationship and constitutive law of the lightweight fill, which was formed by blending expanded polystyrene (EPS) beads with sands. The consolidated-drained triaxial compression tests were conducted on the lightweight fills to observe the stress-strain variations associated with the mixing proportions and confining pressures. It was found that confining pressures and mixing ratios played important roles in affecting the stress-strain behaviors. Based on the test results, a proportion-based constitutive model was established, which was derived from the combination of Cambridge model and the revised Cambridge model. Through verifications, the newly established model was able to depict the stress-strain relationship of sand-EPS beads lightweight fills better than Cambridge or revised Cambridge model.