Nonlinear Analysis Of Seismic Response Of Metro Tunnel Based On Soil-structure Dynamic Interaction Theory

Anti-seismic study on metro tunnel based on soil-structure dynamic interaction theory and dynamic FEM is conducted in this paper.Such issues as significance, category, method of study on seismic response of underground structure is discussed in the paper.A theory termed Nonlinear Analysis of Soil-structure Dynamic Interaction is given in this paper on the basis of related research. Two theories included in it, soil dynamic constitutive theory and contact theory, are discussed. A suggestion about classification of soil dynamic constitutive models is given based on related references. Besides, advantage, disadvantage and applicable range of each model is also proposed respectively. It is especially pointed out that single-yield surface plasticity model is not suitable to dynamic analysis. Related to contact surface model, contact surface element and constitutive relationship of contact surface are introduced and evaluated.A series of problems such as solution of dynamic FEM, nonlinear analysis, seismic simulation, selection of boundary condition and element style are discussed and solutions to them are correspondingly put forward in the paper.Examples concerned with seismic response of single-hole and double-hole circular tunnel are taken on the basis of the proposed theory and method. In the course of analysis Such processes as modal analysis, dynamic response analysis of nonlinear model, comparison of plasticity model with elasticity one and nonlinear analysis of contact surface are included. In addition, related problems like effect of soft soil layer on tunnel and selection of boundary condition are discussed in the analysis. Accordingly a series of helpful discovery and conclusion are made not only to support the corresponding theory, but to present reference and argument for design and evaluation of practical project.