Longitudinal seismic performance analysis of shield tunnels considering the effect of deformation joints
(2.Shanghai Municipal Engineering Design Institute (Group) Company Limited, Shanghai, China 200092)
(3.Department of Geotechnical Engineering, Tongji University, Shanghai, China 200092)
【Abstract】Deformation joints can help shield tunnel accommodate uneven settlement and deformation along the longitudinal direction. At present, the longitudinal seismic analysis of shield tunnel does not take the influence of deformation joints into account, and the influence of deformation joints on the longitudinal seismic behavior of shield tunnel is not clear. In this paper, shield tunnel along longitudinal direction was simplified as a 3D beam element in viscoelastic foundation, and the interaction between tunnel and soil was simulated by foundation springs and dampers. A 3D refinement model was used to simulate the opening and displacement of deformation joints under earthquake by set axial compression spring and shear spring along circumferential distribution. The seismic response characteristics of shield tunnel with/without deformation joints were compared by input ground motion in different input directions and different spectral characteristics asynchronously, and parameter sensitivity analysis of the deformation joints spacing was carried out, which systematically revealed the influence law of deformation joints on the longitudinal seismic behavior of the shield tunnel. It was concluded that deformation joints can effectively reduce the internal force of shield tunnel under earthquake, and the damping effect of the deformation joints was weakened with the increase of their spacing. These conclusions can provide guidance for similar projects in seismic analysis and deformation joint design in the future.
【Keywords】 shield tunnel; seismic response; asynchronous input; deformation joints; damping effect;
(Translated by FAN JC)
 Newmark N M. Problems in wave propagation in soil and rock [C]//Selected Papers By Nathan M. Newmark: Civil Engineering Classics. ASCE, 2015: 703–722.
 Kawajima K. Aseismic Design of Underground Structure [M]. Japan: Kajima Institute Publishing Co., Ltd. 1994.
 LIU Jingbo, LIU Xiangqin, LI bin. A pushover analysis method for seismic analysis and design of underground structures [J]. China Civil Engineering Journal, 2008 (4): 73–80 (in Chinese).
 LIU Xueshan. Analysis and study of longitudinal earthquake resistance of shield tunnel [J]. Underground Space, 2003 (2): 166–172, 226 (in Chinese).
 Shiba Y, Kawashimak, Obinata N, et al. Evaluation procedure for seismic stress developed in shield tunnels based on seismic deformation method [J]. Journal of Structural Mechanics and Earthquake Engineering, 1989 (404): 385–394.
 Hashash Y M A, Hook J J, Schmidt B, et al. Seismic design and analysis of underground structures [J]. Tunneling and Underground Space Technology, 2001, 16 (4): 247–293.
 John C M S, Zahrah T F. Aseismic design of underground structures [J]. Tunnelling and Underground Space Technology 1987, 2 (2): 165–197.
 Gazetas G. Formulas and charts for impedances of surface and embedded foundations [J]. Journal of Geotechnical Engineering, 1991, 117 (9): 1363–1381.
 LI Xiangyu, LIU Guobin, YANG Xiao, et al. Deformation and stress of tunnel structures based on modified longitudinal equivalent continuous model [J]. Chinese Journal of Geotechnical Engineering, 2014, 36 (4): 662–670 (in Chinese).
 Zendagui D, Berrah M K. Spatial variation of seismic motion induced by propagation of body waves [J]. Soil Dynamics and Earthquake Engineering, 2002 (22): 805–811.
 PANG Baojun, YANG Zhenqi, WANG Liwen, et al. Dynamic compression properties and constitutive model with strain rate effect of rubber material [J]. Journal of High Pressure Physics, 2011, 25 (5): 407–415 (in Chinese).