Seismic Response Analysis Of Shield Tunnel

Shield tunnel is an important component of the modern metropolitan lifeline engineering. Therefore the research on its seismic security is very important. In this thesis, the seismic response of single and double-hole parallel shield tunnel is analyzed by the three dimensional nonlinear static and dynamic FEM.In the thesis, the development of seismic response analysis method of underground structure has been reviewed at first. Then, the theoretical basis of seismic analysis of shield tunnel is introduced. In the FEM mesh, an equivalent circle zone, which has the weakly mechanical properties, is set between the concrete segment of the tunnel and the surrounding soil to simulate the mechanical behavior of interface, and the stress-releasing method was used to simulate the excavating process of the soil in the tunnel. A FORTRAN program is developed, and its reliability was proved through some examples.Furthermore, the damping matrix of boundary radiation is deduced using the viscous artificial boundary condition. The dynamic finite element equation is solved by Wilson-θ method. Based on the theory and method mentioned above, taking a single shield tunnel as example, the thesis puts emphasis on the study of static analysis, dynamic time-history analysis, and lining inner force, etc. A series of influencing factors, such as groundwater level, lining's module, soil layer's parameters, and seismic peak acceleration are discussed separately. Consequently, some beneficial conclusions are obtained. Following work achieved above, the regularity of static and dynamic response of double-hole parallel tunnel with different distance was discussed. According this thesis researches, some beneficial rules and valuable conclusions have been obtained for shield tunnel construction.