Abstract: Seismic safety issues must be considered in the design of urban underground utility tunnel. Firstly， the reaction displacement method was used to calculate the internal force of the utility tunnel structure during the seismic， and the weak part of the utility tunnel was obtained. Then the dynamic time history method was used to analyze the seismic response of the utility tunnel， and the numerical model of the soil， structure was established， and the horizontal seismic action was input at the bottom of the model. The soil-structure interface contact unit was used， and the interaction between soil and structure was considered， and the separation and slip between the structure and the soil，the displacement deformation and stress distribution of the utility tunnel under horizontal seismic were obtained. The results show that the standard section structure of the underground utility tunnel has obvious lateral displacement under the action of horizontal seismic action， which is prone to bending and shear failure， but no obvious displacement in the horizontal direction. The weak link in the seismic damage of the utility tunnel structure is on the roof， the bottle plate and the side wall， as well as the wall end of the partition wall， and reinforcement measures are required in the seismic design.

Key words: underground utility tunnel, time history analysis, seismic response, structure deformation, failure mode