Computer Simulations on the Effects of Desaturation on Soil Liquefaction Resistance

Abstract

Ground liquefaction remains as one of the major causes of infrastructure damages during earthquakes. The concept of artificially creating “desaturation or partial saturation” in liquefiable soils has been introduced to improve soil liquefaction resistance. This paper describes the theory and computational implementation to simulate the effects of desaturation on soil liquefaction resistance. The theoretical basis of the computational model is developed based on Biot’s consolidation theory. Computational simulations were conducted to simulate the behaviors of soils under cyclic loading. From these, the trends of pore water pressure evolution and liquefaction resistance of soils under different initial degree of saturation were predicted. Simulation results show that as degree of saturation decreases from 100% to 86%, the number of loading cycles to initialize liquefaction increases from 86 cycles to 237 cycles or increases by 175%. This indicates that desaturation or artificial induction of partial saturation in soils is an effective approach for soil liquefaction mitigation. This can be accomplished by, for example, introducing air bubbles into the pore spaces of soils. While promising, the procedures to introduce air bubbles into soils need to be further developed in light of practice requirements.