Numerical analysis of the seismic response of sand passively stabilized against liquefaction

Abstract

Passive stabilization is a new technique for mitigating the risk of seismic liquefaction in the non-cohesive foundation soil of existing structures. It consists of the low pressure injection (in the soil pores) of colloidal silica, a stabilizer material which transforms into a firm gel after a well-controlled time. This gelation enhances macroscopically the mechanical response of the soil skeleton-pore fluid system. The microscopic mechanism of improvement has not yet been established, thus prohibiting the formulation of constitutive models. This paper explores the possibility of using existing constitutive models for simulating the response of stabilized sands. A well-established plasticity model for sands (NTUA-SAND) is used herein for the simulation of a pertinent dynamic centrifuge test, after re-calibration or in combination with the seemingly relatively compressible colloidal silica as the pore fluid instead of incompressible water. © The authors and ICE Publishing: All rights reserved, 2015.