Characteristics of the Longitudinal Seismic Response of Shield Tunnel

With dynamic finite element method considering soil-structure interaction effects,this paper analyzes the influences of traveling wavelength,foundation stiffness and damping coefficient on the longitudinal seismic response of shield tunnel by simulating longitudinal screwed joint with zero-length,three-degree of freedom spring element.Analysis results show that the breaking bending moment occurs when the traveling wave is input from horizontal direction.The breaking bending moment will decrease with the increase of wavelength and damping coefficient.The coefficient of foundation stiffness will have less impact on the breaking bending moment.The maximum axis force and moment of the segment joint under the action of traveling wave will decrease with the increase of wavelength.The values of foundation stiffness coefficient and damping coefficient will have less impact on the maximum moment.As a result, it is suggested that,for the design calculation of practical engineering,importance should be attached to the selection of the dynamic parameters of earthquake input,and smaller damping coefficient should be adopted.