Study On The Regulations Of Strong Earthquake Damage And Thermal Insulation And Shock Absorption Technology Of Tunnel Across Thermal Fault

With the development of traffic construction in the west of China,it is inevitable that the traffic tunnel to avoid crossing the high temperature stratum in the high intensity earthquake area when selecting the route.If there is an earthquake,the structural safety of the traffic tunnel will be seriously damaged.In order to improve the safety of the tunnel structure,this paper mainly studies the influencing factors and rules of the strong earthquake damage,the failure mechanism,the design and calculation method of the fault resistance and the disaster prevention technology of the cross thermal fault tunnel.The research results are of great significance to the development of the thermal insulation and damping technology of the cross thermal fault tunnel.The main conclusions are as follows:The numerical simulation is used to study the influencing factors and rules of the strong earthquake damage of the tunnel across the thermal fault.The results show that with the increase of the surrounding rock temperature,with the increase of the angle of the thermal fault,the width of the fracture zone and the deterioration of the mechanical properties of the surrounding rock in the fracture zone,the safety of the tunnel structure decreases gradually,but the high temperature has less influence on the safety of the tunnel structure(below 2.91%).The numerical simulation is used to study the regulations of the strong earthquake damage of the tunnel.The results show that the main cause of the structural damage of the tunnel is the earthquake vibration;the main cause of the structural damage of the tunnel is the fault dislocation,which accounts for about 80% of the total damage,The failure mode is the tunnel structure The cross section shows conjugate shear failure of about 60°.Based on the theory of reaction displacement and the theory of thin-walled circular shell,the design and calculation method of cross thermal active fault tunnel is established.The numerical simulation method is used to verify the theoretical solution.The theoretical solution is less than 30% larger and more conservative.It can be used for the design of disaster prevention structure of tunnel across thermal active fault.In order to improve the disaster prevention technology of cross thermal fault tunnel,this paper studies the thermal insulation and shock absorption technology of cross thermal fault tunnel by means of test piece test and numerical simulation.The results show that the comprehensive thermal insulation and shock absorption technology has the best thermal insulation and shock absorption effect(compared with the plain concrete,the thermal insulation effect is increased by 3.26%),The damping effect is increased by 176.68%.The insulation and damping effect of steel fiber high damping composite structure is the second,and the insulation and damping effect of plain concrete high damping composite structure is the worst.The research results are of great significance to the development of thermal insulation and shock absorption technology of cross thermal fault tunnels.