Integral Seismic Deformation Method: A Pseudo-static Method for Seismic Design of Underground Structures

Abstract

The traditional seismic deformation method is among the most popular pseudo-static methods for seismic design of underground structures by considering soil-structure interaction through the layout of foundation springs. It can be mechanically proved that the traditional method has a relatively rigorous theory except the discrete foundation springs. A new kind of pseudo-static method, called the integral seismic deformation method, is proposed in this paper by establishing the finite element models of hollow ground and integral soil-and-structure. Equivalent seismic loads of the proposed method are composed of three parts: shear stress of free field, inertia force of underground structure and equivalent nodal forces acquired by the static analysis of the hollow ground model. In order to verify the efficiency of the proposed method, a series of numerical calculations of Daikai subway station are conducted by the two pseudo-static methods and the dynamic time-history analysis, respectively. Comparison of the calculation results shows that the proposed method achieves high precision and extensive applicability. It is also convenient and time-saving to operate. Therefore, the integral seismic deformation method can be widely used for seismic design of underground structures.