Shaking Table Test And Numerical Simulation Of Muti-story Subway Station

With the rapid development of economy in China, the pace of urbanization becomes faster and faseter, and gradually villages become cities. The earlier cities grow towards the direction of magacity or supercity. As a result, populations become bigger and bigger, which make the cities'former transportation systems insurficient for the growing people. To solve this problem, many big cities have already or prepared to develop underground space and underground traffic. Underground structures belong to public places with high density of people. Once the structures were destoryed under earthquake, large casualties and underground traffic problems will be caused. And for the inherent invisibility, it is very difficult to repair the damaged structures and will caused substantial economic losses. So it is a very important problem to recognize exactly how the underground structures behave under earthquake and give the basic principles and suggestions in aseismic design. Based on summarizing of predecessors' aseismic research methods of underground structures, this paper will make a deep discussion on shaking table test and finite element method simulation. Specifically this paper has accomplished the work as followings:1. Constitutive models for soilTwo kinds of most common-used soil constitutive models are introduced. One is Mohr-Coulomb plasitic model which is based on the Mohr-Coulomb strength criterion; the other is Duncan-Chang nolinear elastic model, which is based on the hyperbolic assumption. In this paper, the process of deduction of its plane strain form will be given for the latter model. In the meal time, using the UMAT interface, the method to add Duncan-Chang model to the ABAQUS material libirary will also be given.2. Constitutive models for concreteA most common-used concrete constitutive model based on damage theory is introduced, that is, the CDP model, which is short for Concrete Damaged Plastic. The paper raises for the first time the method to determine the damaged parameters on the basis of the current concrete structure design code. Numerical example shows that, the method is simple and workable, and the result accords with the expectation very much.3. Boundary problem in numerical simulation The reason for causing boundary problem in numerical calculation is discussed. Taking one dimensional wave propagation problem for example, the viscous boundary formulas are deduced. Numerical example shows that, viscous boundary can effectively absorb wave energy and reduce the wave reflection, which makes the result closer to the actual conditions. In addition, the method to realize free-field boundary conditions in ABAQUS is raised up for the first time. Numerical result shows that this kind of method is accurate and effective, which makes it possible for ABAQUS to input two-directional seismic wave.4. Shaking table test for subway stationShaking table test for subway station buried in full clay was performed. Through comparative analysis, basic design principles and suggestions for underground structures are brought up.5. Numerical simulation for shaking table testBased on the large general-purppse FEM software ABAQUS, numerical simulations for the shaking table test are fully performed. Through the comparative analysis between simulation results and actual results, the conclusion is to be drawn that numerical simulation is an effective method to perform seismic response analysis for underground structures.