Numerical Evaluation of Liquefaction Resistance for Desaturated Sands
Desaturation has been a cost-effective and straightforward ground improvement method for liquefaction mitigation. Recent advancements in geotechnical numerical simulations have allowed for the simulation of desaturated soils in dynamic problems. The objective of this study was to evaluate the numerical capabilities of predicting liquefaction resistance for desaturated sands. A finite-element method (FEM) analysis was performed to simulate a large shaking table test (STT) that aimed to evaluate the desaturation ground improvement method for liquefaction mitigation. This paper consists of three parts: (1) a brief description of STTs carried out by the National Institute for Land and Infrastructure Management (NILIM). In the STTs, the degree of saturation Sr was controlled to within approximately 80%–100%. (2) Simulation of elemental scale tests for desaturated sands under undrained triaxial cyclic conditions. (3) FEM analysis of the STTs. Numerical analyses were performed using LIQCA2D17. The results showed that the numerical analysis reasonably predicted the ground motion intensities and pore water pressure responses of the desaturated sand. The numerical analysis indicated that volumetric strains and pore water seepage induced changes in Sr during loading. These phenomena resulted in a transition from desaturated to saturated conditions.