| As an important transportation facility in the city, the subway system has been developed after in the world because of its advantages of low pollution, low noise and ground space saving. In recent years, the subway tunnel protection methods have been vigorously researched and developed, set off a wave of subway construction in China. As a result,the safety protection of subway structure becomes an urgent problem to be solved. The subway tunnel to bring huge traffic convenience to people at the same time, there are some security risks, because the subway space is closed, poor ventilation, crowded population, once the occurrence of terrorist bombings, often cause huge casualties and economic losses.Among them, the composite plate can absorb the shock wave and shear strength advantages the higher the strong applicability in tunnel explosion protection. Protection methods are known, the protection methods in the two aspects of protection are not ideal results, therefore,this paper proposes that the use of composite steel plate door model protection method of shock wave explosion has important significance on the research of subway explosion protection measures tunnel. The main research work and results are as follows:(1) In order to analyze the explosion load accurately, composite steel plate protective effect, combined with the Nanjing metro operation,combined with knowledge of key points in fluid dynamics and explosive force of the basic theory research, through dynamics analysis software LS-DYNA to establish protective steel plate lining structure of metro tunnel explosion numerical model, three-dimensional numerical model of the explosive air composite plate lining - surrounding soil, and by using the ALE method and the fluid solid coupling method, installation of dynamic composite steel metro tunnel explosion response simulation.(2) The installation of propagation of metro tunnel composite plate in explosive shock wave were analyzed, 10kg TNT and 30kgTNT explosion, in the installation of a subway tunnel composite steel protective structure, explosion shock wave reflection and superposition attenuation law, and makes a comparative analysis and communication the law of explosion shock wave protection structure is not installed,results show that the composite steel plate door under the action of explosion shock wave peak will rise slightly, but the magnitude is very small, the propagation rule of explosion wave and composite steel plate is not installed under the condition of similar, no major changes.(3) Analyzed in composite steel plate protection for influence on the stress characteristics of lining structure of metro tunnel (section displacement, speed, acceleration and stress), of 1.1m 10kg TNT from the bottom lining and 30kgTNT explosive was the dynamic response analysis. By comparing the results with the composite the numerical model of steel plate is not installed, as the distance increases, the pressure can have multiple peak and rapid decay in the protective effect of composite steel plate, velocity and acceleration of every point significantly reduced, has good protective effect. And through the 10kg TNT and 30kgTNT two kinds of explosive explosive lining section explosion the displacement, velocity, acceleration and stress variation analysis results, verify the installation of protective performance of tunnel lining structure of composite steel plate under different explosive equivalent conditions. |
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