Abstract Based on the Xi?an metro tunnel passing through active ground fissure zones,the interaction between tunnel structure and soil under metro tunnel which orthogonally crossing the ground fissure belt is studied by a physical modeling experiment. When the upper and lower plate dislocate relatively,the longitudinal strains of structure,the relative displacement at the bottom of the tunnel and the peripheral soil pressure are analyzed. The test results indicate that the load transfer mechanism of the interaction between the tunnel structure crossing the ground fissure and soil contains four factors,specifically,the structure stiffness effects,supporting action of underlying layer,the friction force between tunnel structure and soil,and the effect of contact between the hanging wall and the footwall. According to the deformation behavior and the strain variation rule,the mechanical model for the interaction between tunnel and soil is created under the void state which is at the bottom of the tunnel. The research results may provide references for the structure design of the tunnel when the Xi?an metro tunnel crossing the ground fissure. Through the comparison of several different sections of tunnels,two points of views are come up. The first one is the horseshoe tunnel should be utilized in preference to other tunnels when the metro tunnel orthogonally crossing the ground fissure belt,which can improve the structure stiffness. The second one is controlling the crack of the concrete tunnel which located in the lower plate of the ground fissure at the same time,and coping with the waterproof treatment.
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