The Seismic Response Analysis Of The Subway Station In Soil With Saturated Weak Intercalations

Exploiting underground space resources and constructing subway is an effective way to solve the traffic jam problem in cities. Subway station is a transport hub with a long life cycle and the concentration. Once the subway station is damaged by the earthquake, may result in significant casualties and damage to the structure of the station. But the restoration work is more difficult than the general structure on the ground, and the indirect economic losses is far greater than the direct losses, as well as there will be a significant impact on the social life. Thus, it is very urgent that people must have some update understanding of the seismic problem of the underground structures, and we have to do more research on the seismic ability of the underground structures. The statistic data of the disaster caused by earthquake in recent decades shows that underground structures are more likely to be damaged when they in complicated geology and geological environment,such as nonuniform stratum, soft soil, soft interlayer nearby and so on. When strong earthquake occurs, the relative sliding between the soft interlayer and the surrounding soft and the deformation of the nonuniform stratum is a huge security risk for the underground structures.The main purpose of this paper is to find a finite element method which considers the saturated soil with weak interlayer nearby the structure. On the basis of the explicit finite element methods of dynamics analysis about single-phase and fluid-saturated porous media, which are established by Liao Zhenpeng and Zhao Chengang, taking into account soft interlayer existing in the surrounding soil, this paper establishes a seismic response analysis model which can be used in Subway station structure-saturated soil coupled system. By numerical modeling, the seismic responses of the key positions in stratum and subway station structure are showed under the plane P wave and plane SV wave. The factors, such as the depth and thickness of the soft interlayer, soil properties and so on, is discussed on the influence to the dynamic response magnification coefficient of subway station structure. The paper studies the measures to reduce the earthquake disaster caused by soil interlayer though changing the depth, the forms, and the materials of station when the depth and thickness of the soft interlayer, and soil properties are fixed. Comparing and analyzing and the results of numerical simulation, the paper gives some analysis and suggestion to avoid and reduce the damage caused by soil interlayer in earthquake for the Civil Engineering projects.