关键词: 振动台模型试验, 软弱场地, 地铁车站结构, 地震损伤特性, 空间效应

Abstract: As one of the series large-scale shaking table tests on the failure mechanism of subway station structure, a large-scale shaking table test on frame type subway station structure model in soft silt clay under near- and far-field strong ground motions is conducted, in which the acceleration, pore pressure and earthquake-induced settlement of the model ground as well as the acceleration, strain and horizontal displacement of the model structure are measured and analyzed. The results show that as the seismic wave propagates in the model ground, the amplitude of the low frequency components increases while the amplitude of the high frequency components decreases from the bottom to the top of the ground. Under strong ground motions, the fundamental frequency of the model ground significantly decreases, and the ground exhibits a remarkable amplification effect for low frequency components and wave filtering effect for high frequency components. The pore pressure ratio of the model ground slightly increases. The development processes of pore pressure ratios under different ground motions are greatly different, and show an obvious spatial effect. Under near- and far-field strong ground motions, the acceleration responses of the model structure are obviously different. The model structure has a significant spatial effect on the acceleration response of the ground motion for the soft ground. The frame structure does not show an obvious floating phenomenon and its relative deformation is small. The frequency characteristics of the ground motion have an obvious influence on the deformation mode and magnitude of the side wall for the model structure. The most severely seismic damage part is located at the middle column of the model structure. The whole model structure is slightly seismic damaged and in nondestructive state.

Key words: shaking table model test, soft ground, subway station structure, seismic damage behavior, spatial effect