软硬相间地基中地铁隧道P波斜入射下的动力响应

he subway tunnel in a site interbedded with soft and hard soil was evaluated in this study by using seismic response simulation. A three-dimensional finite element model of subway tunnel and the site interbedded by soft and hard soil under oblique incidence of P wave was created, in which the soil-structure dynamic interaction and multi-point excitation were simultaneously considered. And the dynamic response of the subway tunnel were calculated and systematically analyzed. The results showed that seismic wave incident angle has a significant effect on the dynamic response of the subway tunnel. The traditional vertical incident seismic wave input method showed a certain degree of insecurity. In addition, the dynamic response of the subway tunnel was constantly increasing with the increasing soft soil district. Thus, the soft soil district is unfavorable to seismic loading. The increase of tunnel lining concrete strength grade led to reduction of displacement and acceleration of the tunnel structure and the significant increase of moment. Therefore, the increase of tunnel lining concrete strength grade has no significant effect on the improvement of the seismic resistance level of subway tunnel whereas it will increase the internal force of the lining structure.