关于地铁地震响应的模型振动试验及数值分析

Dynamic behaviors of subway structure subjected to strong earthquake motions using shaking table tests and dynamic analyses

为明确大地震时地铁的破坏过程及原因,以1995年日本阪神-淡路大地震中遭受严重破坏的神户大开地铁车站为对象,进行了一系列的模型振动试验和动力有限元分析。对于作用于地下结构的地震动土压的发生原理、地震波输入方向、结构的埋设深度、地基与结构间的刚性比对地震动土压的影响及在地基-结构系统的非线性响应下结构周围地基终局状态时的地震动土压进行了研究。明确了地震动土压的极限值及在大地震时周围地基的残余应变引起的静止土圧力的存在。为今后改进地震土压力计算方法、提高地下结构抗震设计水平提供了依据。

In order to clarify the dynamic behaviors and the damage mechanism of the subway structure, a series of shaking table tests and dynamic finite element analyses of Dakai subway station damaged in 1995 Hyogoken-nanbu earthquake were performed. The mechanism of the seismic soil pressure acting on the structure, the effects of the input directions of the sinusoidal and random waves, the embedded depth of the subway structure and the shear modulus ratio between the structure and the surrounding ground were investigated. Moreover, from the nonlinear seismic response analysis, the seismic soil pressure in the limit state of the surrounding ground were evaluated. It was resulted that the seismic soil pressure would reach a peak value; and the seismic soil pressure consists of dynamic component and static one caused by residual strain of the ground due to strong earthquake motions. The foundation is provided for amending the calculation method of seismic soil pressure and improving the anti-earthquake designing level of underground structure.