Numerical Simulation On Fire Accident For Rist Prevention In The Tunneling Process Of A Narrow And Long Tunnel

In the tunnel construction process, the staffs are easily fatigue and depression in the long-term work in a closed environment. When work in the narrow and long tunnel, carbon dioxide and other gases are more easily concentrated as the air is only supplied by air duct, and the staffs are easily fatigue and insane as the air flow is poor. All these factors would cause operational errors, or a number of staff discipline and smoking behavior may lead to fires. In the tunnel construction site, due to the long-term operation of shield machine and other equipment, control equipment are too long working and heating, it may cause a fire. Pre-study on the possible fire can set the disaster prevention facilities and provide a safe escape. It can avoid the death and economic losses.The paper constructs the numerical model according to the Shanghai grass-sand water tunnel project as a prototype, the numerical simulation technique applied to the risk prevention in the tunneling process. According to different fire reasons to set heat release rate, numerical simulation are tested to study the spread of smoke and temperature low in long and narrow tunnel, and the main factors to determine the impact of the fire smoke and temperature are found.Using computer's parallel computing technology, Linux system of Dawning 5000A supercomputer is to start the FDS program and call the MPICH process, to solve difficulty of multi-grid numerical model and large amount computing .The large-scale numerical parallel computing and the actual project phase are combined to study the law of the smoke and temperature in the long and narrow tunneling process.Finally, using the computer simulation technology to simulate the water curtain spray of shield machine, the water curtain in the fire shield machine in an active role in risk prevention is verified. And the main factors of the effect of water curtain are analyzed and found, while for the original water curtain inadequacy an optimized and improved water curtain system is designed and tested by numerical simulation.