考虑热位差的特长隧道斜井反井法施工通风研究

Study on Ventilation of Inclined Shaft of Extra Long Tunnel by Reverse Well Method Considering Thermal Potential Difference

在特长隧道修建过程中,斜井的快速施工是影响整个工程进度的一个关键因素,当前反井法在斜井施工中得到大量应用及推广。而在其施工过程中,由于掌子面与交叉口热位差的存在极大地增加了通风难度。基于此背景,本文采用数值模拟方法,利用有限元软件FLUENT研究热位差对斜井反井法施工通风的影响。结果表明:热位差的存在不利于洞内污染物排除,在通风系统中产生阻力的不利影响,因此在反井法施工通风设计计算沿程阻力时,应考虑热位差对洞内风流的影响。结合现场测试数据对数值计算结果进行可靠性验证,并对斜井反井法施工通风阻力计算公式进行修正。研究成果在二郎山特长隧道施工中得到应用与验证,可为今后其他类似工程提供参考。

In the construction process of extra long tunnel,the rapid construction of inclined shaft is a key factor affecting the whole project progress.At present,the reverse well method has been widely used in the construction of inclined shaft.In the construction process,the existence of thermal potential difference between the tunnel face and the intersection greatly increases the difficulty of ventilation.Based on the above background,this paper uses the numerical simulation method,using the finite element software FLUENT to study the influence of thermal potential difference on the ventilation of inclined shaft construction by reverse well method.The research results show that the existence of thermal potential difference is not conducive to the removal of pollutants in the tunnel,and it has adverse effects on the resistance in the ventilation system.Therefore,in the ventilation design of inclined shaft construction,when calculating the resistance along the way,the influence of thermal potential difference on air flow in tunnel should be considered.The reliability of the numerical results is verified by the field test data,and the calculation formula of ventilation resistance of inclined shaft by reverse well method is modified.The research results have been applied to the construction of Erlangshan super long tunnel,which can provide reference for other similar projects in the future.