长大隧道压入式施工通风三维动态数值模拟分析

Analysis of Three Dimensional Dynamic Numerical Simulation of the Construction Ventilation of Long Tunnel

长大隧道在主隧道贯通前的施工通风问题是多年来长期制约隧道通风的一个重要难题,虽然工程实践中不断探索解决办法,但效果一直不是特别理想。利用有限元分析软件对设置有竖井的长大隧道在主隧道贯通前的压入式通风的湍流动能、通风速度场、空气压力场、有毒气体浓度场进行了三维动态数值模拟。模拟结果标明,设置有通风竖井的长大隧道采用压入式通风,有毒气体排出快,通风效果好;但仅依靠竖井进行自然通风不能达到快速排出有毒气体的目的,必须借助在竖井内安装风机等通风设备对风流进行合理引导。

The construction ventilation of long tunnel in the main tunnel is a very important prob- lem that haslong restricted the tunnel ventilation for many years. Although the engineering practice has been exploring the solution, the effect is not particularly ideal. By using the finite element analysis soft- ware,thethree-dimensional dynamic numerical simulation of the turbulent kinetic energy, the ventilation velocity, the air pressure field and the toxic gas concentration field of the tunnel with the shaft of the tun- nel is carried out. The simulation results indicate that the ventilation shaft is provided with a pressure of ventilation, the toxic gas is discharged quickly, and the ventilation effect is good, but only the natural ven- tilation can not reach the purpose of rapid discharge of toxic gas.