曲线隧道施工通风沿程阻力损失数值模拟

Numerical Simulation of Construction Ventilation Resistance Loss along the Curved Tunnel

山岭地区修建隧道,受地形、地质等条件限制,时有采用曲线隧道方案。相比于传统直线隧道,曲线隧道在施工通风方面存在差异。本文依托某特长曲线隧道工程,采用三维数值模拟,建立"风机-风管-隧道"施工通风系统模型,对不同半径、不同风速条件下,曲线隧道及风管沿程阻力损失进行计算,并与直线隧道进行对比,得出下述结论:(1)曲线隧道沿程阻力损失系数随曲线半径减小而增大,受风速影响较小,与掌子面距离400 m后发展稳定,并拟合出计算公式;(2)风管沿程阻力损失系数受隧道曲线半径和风速影响较小,与风机距离100 m左右已发展稳定。本文可为曲线隧道施工通风沿程阻力损失系数的选取提供参考,具有实际工程意义。

The construction of tunnels in the mountainous areas is restricted by terrain and geology,and the curve tunnel scheme is adopted.Compared with the traditional straight tunnel,the construction ventilation of curved tunnel is different.Based on the extra long curved tunnel,this paper uses three-dimensional numerical method to establish a"fan-wind pipe-tunnel"construction ventilation model,and calculates the resistance loss of curved tunnels and wind pipe under different curve radius and the speeds of wind conditions.And the results are compared with the straight tunnel.The following conclusions are drawn.(1)The resistance coefficient along curved tunnel increases with the decrease of curve radius,and it is less affected by wind speed.It develops steadily after 400 m away from the working face,and the calculation formula is fitted.(2)The resistance coefficient along the wind pipe is less affected by the radius of the tunnel and the wind speed.It develops steadily after 100 m away from the fan.This paper can provide a reference for the selection of resistance coefficient for tunnel construction ventilation,which has practical engineering significance.