3D Numerical Modeling of a Geotechnical Seismic Isolation System for Mitigating Liquefaction-Induced Damage Potential

Past earthquake events demonstrated that liquefaction may compromise the stability of structural systems with high nonlinear deformations, lateral spread, and settlements. This study investigates the use of geotechnical seismic isolation (GSI) as a mitigation technique for soil liquefaction effects. Three-dimensional (3D) advanced numerical simulations are performed using the state-of-the-art platform OpenSees (version 3.7.1) that captures efficiently soil deformability, as well as the nonlinear effects of liquefaction. The structure under consideration is a low-rise RC building sitting on a shallow foundation with a GSI layer surrounding the shallow foundation. This system is subjected to five selected ground motions to demonstrate the efficiency of the GSI system in reducing the excess pore-water pressure that is the fundamental cause of soil liquefaction. Several key response parameters are considered for the soil (shear strain, excess pore pressure, longitudinal displacement, and ground settlement) and the structure (base shear, roof acceleration, and interstory drift), in order to support the use of GSI as a mitigation technique and to illustrate the stability of the entire system.