Experimental Study And Numerical Simulation Analysis Of Fire Resistance Performance Of Concrete Segment Component Of Shield Tunnel

Fire would cause serious damage to the tunnel lining structure, for fire resistance performance of tunnel structure, it is an important concern to protect tunnel structure from fire in tunnel fire safety engineering. Experimental research and numerical simulation analysis are applied to study the fire resistance performance of concrete segment component of shield tunnel at three levels i.e. material, structural element and structural system. The main researches are as following:(1) Though the experimental research on fire resistance performance of concrete block, laws of mechanical characteristics of concrete during and after high temperature are analysised, effect of temperature on impermeability of concrete before and after high temperature is obtained.(2) Though the experimental research on fire resistance performance of concrete segment component of shield tunnel under coupling of load and temperature, the mechanical behavior under fire is studied and the laws of temperature field distribution and deflection change are summarized. Through the static loading test, the failure mode and residual bearing capacity of damaged member are studied.(3) Analysis on coupled thermal-mechanical simulation of concrete segment component of shield tunnel by established finite element model. Verify the accuracy of simulation results by compare the simulation results and test results, provide the basic data for the further theoretical studies of residual bearing capacity of concrete segment component structures after fire.(4) On the basis of test research and theoretical analysis of concrete segment component, by using finite element analysis, temperature field distribution and mechanical characteristics of shield tunnel structure during and after fire are carried out, the temperature field distribution and deformation features after fire are obtained, ultimate bearing capacity of different fire scenarios are analysised.(5) On the basis of test research, theoretical analysis and numerical simulation, fire protection measures in segment structure of Nanjing Yangtze River Tunnel are proposed.The obtained key characteristics of fire resistance, temperature distribution and mechanical characteristics can provide not only direct guidance for the fire resistant design of concrete segment component of shield tunnel structures, but also important practical and guilding significance for similar engineering.