Study on the influence of sand liquefaction caused by earthquake on the floating of underground structures

Abstract

The effective stress of the soil decreases and the pore water stress increases under the earthquake, which causes the sand to liquefy. The vertical deformation of the ground caused by the liquefaction of sand causes serious damage to the ground and the buried structure, which seriously threatens the safety of underground lifeline engineering. In order to study the impacts of sand liquefaction, the language FORTRAN was used to establish a finite element model under the earthquakes. The floating of various locations of the underground structure under different earthquakes was studied, and the factors affecting the floating were discussed. The results show that during the earthquake, the liquefaction of sand occurs, which causes the underground structure moves up due to buoyancy, and the soil mass from the structure collapses. The liquefied sand diffuses to the surrounding area after the earthquake, causing the sand beneath the underground structure to be lost, and the building will return to its original position or even collapse. The results provide references for the anti-floating research of underground structures.