Abstract：The impacts of metro operation against shield tunnel are analyzed. An elastoplastic three-dimensional dynamic finite difference modeling is employed. By considering the joints，the segments and the weak stratum，numerical simulations are performed for dynamic response of shield tunnel buried in thick soft soil under vibrating load induced by metro train. Comparative analysis has been done for joint-considered and non-joint-considered of segments lining. Results of numerical simulations show that metro operation induces significant dynamic response in shield tunnel. The dynamic response of shield tunnel is attenuated gradually from bottom to top of tunnel. The severe dynamic response zones are mainly distributed in the range of lower half of tunnel. The dynamic response of segments lining is affected by the arrangement of joint. In two horizontally symmetrical corresponding positions of segments lining，dynamic response of the one approaching to joint is severer than that of the one apart from joint. The severe dynamic response zones of tunnel foundation cling to around segment-ring. The nearer the zone is to segment，the severer the response is；and the nearer the zone is to the bottom of tunnel，the severer the response is. The dynamic response of stratum is damped quickly from tunnel wall to deep stratum. The obviously vibrated zones of stratum are mainly distributed in the range of about two times the tunnel scale from tunnel axis. The errors will be large for the exact analysis of dynamic response of segments lining structure itself if the segments lining is regarded as a whole tube body with non-joint-considered，so the joints should be considered for segments lining structure analysis. While the difference of results between joint-considered and non-joint- considered is small and it can be ignored somewhat for analysis of dynamic response of stratum. Therefore，the joints can be ignored，and the segments lining structure can be regarded as a whole tube body for stratum analysis to improve efficiency.
