Analysis of liquefaction susceptibility of nearly saturated sands

Abstract

SUMMARYA new constitutive formulation for simulating the behaviour of nearly saturated sands under seismic loads is presented. The formulation is based on combining the Henry's law for dissolution of gas in water, the ideal or perfect gas law and the law of conservation of mass. The effects of transient air dissolution in water on the compressibility of partially saturated soils are also taken into account. The model was calibrated based on numerical simulations of isotropically consolidated cyclic triaxial tests conducted on partially saturated samples of Toyoura sand. A multi-yield plasticity soil constitutive model implemented in the finite element code DYNAFLOW was used for these numerical simulations. It is shown that the formulation proposed here is able to reasonably predict the soil cyclic undrained behaviour at various degrees of saturation (95% and higher).

Three-phase coupled seismic analyses of unsaturated/saturated grounds

“…Coupled analyses of unsaturated soil response have been presented by Meroi et al (1995), Zienkiewicz et al (1999), Uzuoka et al (2001), Khoei et al (2004), Mehrabadi et al (2007) and Marasini & Okamura (2015) without determining the pore air pressure explicitly. They assumed that the pore air pressure was zero, or the pore air pressure was the same as pore water pressure.…”