Abstract:A simplified mechanics model of soil-underground structure system is established for the effect of lateral deformation of underground structure. Considering the non-linear deformation effect of underground structure, the three-fold line model is adopted to simulate the deformation of underground structure, and the ideal elastic-plastic model applies for the interaction between soil and underground structure. Based on the two models, the analytical solution of lateral deformation of underground structures in liquefied site is obtained. And the analytical solution is verified by the response displacement method, which proves its reliability and validity. The result shows that the analytical solution and the results calculated by the response displacement method are consistent when Ug is not large enough. However, with Ug get larger, the analytical solution and the response displacement results are consistent with the change of depth, but the analytical solution is larger than that of the response displacement method. In addition, the influence induced by different thickness of overlaying soil on underground structure is different. The bending moment of underground structure reaches the maximum near the interface between liquefied layer and non-liquefied one, and its position gradually decreases with the increase of embedded soil depth.