Abstract:

The statistical data of disasters caused by earthquake show 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, etc. The seismic response of the metro station in the site with saturated soft interlayer is hereby analyzed. On the basis of the explicit finite element methods of dynamics analysis about single-phase and fluid saturated porous media, taking into account soft interlayer existing in the surrounding soil, a seismic response analysis method which can be used in metro station structure-saturated soil coupled system is established. By numerical modeling, the seismic responses of the key positions of metro station structure are shown under three actual earthquake recorders with different spectra characteristics which incident as the plane P wave. The factors, such as the location and thickness of the soft interlayer, are discussed in their influence on the dynamic response of metro station structure. The study results show that the soft interlayer has a very negative amplification on the dynamic response of metro station structure; and the amplification is the most unfavorable when the soft interlayer inside the metro station.

Key words: saturated soft interlayer, metro station, dynamic response analysis, explicit finite element method