Research On Structural Dynamic Response And Bolt Failure Of Shield Tunnel Under Impact Force Of High-speed Train

With the rapid development of railway enterprise, the speed of train has been improved greatly. When train derailment accident happen, the strong impact force produces tremendous threat to tunnel structure and the safety of the passengers. Practical and effective assessment of tunnel structure under train derailment is important to preventing the possible disaster which is induced by the damage of structure. This paper based on Project of the Shiziyang Tunnel, carrying out research on the tension and compression damage and impact deformation of segment lining, the stress of reinforced, the bolts deformation and bolts failure of segment lining.The main works and results are as follows:1、Based on finite element software using infinite element boundary, by introducing the rigidity reduction coefficient, to reflect the influence of the overall flexural properties which joints on the lining structure. Based on steel finite element model, to research the value, displacement and the dynamic response of stress under the condition of the impact with the same speed and angle on the 3 surrounding rock grades. Getting the rules of the dynamic response of the tunnel and reinforced under the impact load of high-speed train with the change of the level of the surrounding rock.2、Tensile springs% bending springs、shearing springs are adopted to simulate the joint bolt. The springs is good at resisting tension, but fails under compression in axial direction, and the positive and negative bending stiffness nonlinear characteristics of the bending spring is considered. under the impact load of train, study the bolts’ axial force, bending moment, axial deformation and analysis the response of reinforcement stress on the region which impacted.3、Considering joint bolt failure, study the influence of impact velocity, bolt strength level and bolt diameter on the segment dynamic response.