Research On Seismic Response Of Metro Station With Centrifuge Shaking Table Model Test

With the ever-acceleration process of urbanization in China,traffic congestion appears in many cities,especially in Beijing、Shanghai、Hangzhou and other cities.Development of underground space and urban subway has become the first choice to solve traffic congestion in many cities. Many home and abroad subway stations have been built or to be built in high seismic region, once suffered from earthquake, it’s difficult to be repaired and its cost is biggest. Therefore, it’s very important to develop seismic research work and seismic response of subway station and other underground structures. Seismic response regularities and failure modes of subway station in saturated sand foundation have been studied by centrifuge shaking table model test in this paper. Major research works are as follows:(1) To achieve the purpose of observe subway station’s seismic failure modes in centrifuge shaking table model test, series of test about microconcrete with low strength have been carried out based on summary of domestic and foreign scholars’research. Test results show that the strength of microconcrete is related to mix proportion、grain size distribution cement grade and curing age. Microconcerte with low strength can be compounded by adjusting mix proportion、 grain size distribution and addition amount of water-reducer, which can be meet the requirements of geotechnical centrifuge model test.(2) A vacuum saturation equipment is designed in order to meet the saturation of model foundation in geotechnical centrifuge model test.This system is not only makes up for the deficiency of conventional saturation device, meets the special requirements of model foundation in geotechnical centrifuge model test but also controls the saturated flow precisely and ensures the quality of saturation.(3) A template used for pouring subway station has been designed and a subway station model has been poured. Two different metro station models have been made using two different strength microconcretes and then completed seismic non-destructive and destructive testing.(4) Seismic non-destructive and destructive testings of subway station in saturated sand foundation have been carried out, while Seismic response regularities and failure modes of subway station in saturated sand foundation have been studied. Acceleration pore pressure and soil pressure response regularities of sand foundation have been also studied. Besides the mechanism of earthquake damage to subway station has been explored.