引汉济渭椒溪河隧洞施工通风数值模拟

发布时间：2019-06-19 06:48

【摘要】：引汉济渭工程是陕西省为缓解关中渭河沿线城市和工业缺水问题,而提出的由汉江调水到渭河流域的大型水利工程。椒溪河段工程为穿河段,地形地质相对复杂,隧洞施工期的通风问题也相对比较严重。采用CFD(Computational Fluid Dynamics)数值模拟方法对带有支洞隧洞的通风过程进行模拟,研究几种典型工况下隧洞内的流场和浓度场在施工期时随时间的变化规律,分析掌子面以及支洞内涡流对气流及有害气体分布的影响。在气流排散通道不顺畅时,掌子面附近的涡流区域内涡流的大小和位置呈现周期性的变化,并随通风时间的增加影响范围逐渐降低。隧道爆破产生的有害气体和烟尘会随着气流的流动发生移动和扩散过程,并逐渐排向洞外。通过对隧洞主洞与支洞内气流和有害气体排散过程的研究,得出隧洞爆破后在通风作用下隧洞的掌子面附近和支洞与主洞的交叉位置处形成涡流区,涡流的产生和变化不断的消耗通风的机械能,降低通风效率,对有害气体的排散造成一定的阻滞作用,隧洞内有害气体的排散过程包括移动和扩散两方面,移动过程将CO排向洞外,扩散过程不断的降低洞内CO峰值,总结出了不同工况下隧洞内达到安全浓度的时间,对隧洞施工进度给出一定的参考意见。
[Abstract]:In order to alleviate the problem of urban and industrial water shortage along the Weihe River in Guanzhong, Shaanxi Province proposed a large-scale water conservancy project from Hanjiang River to Weihe River Basin in order to alleviate the problem of urban and industrial water shortage along the Weihe River in Shaanxi Province. The Jiaoxi reach project is a cross-river section, the topography and geology are relatively complex, and the ventilation problem during tunnel construction is also relatively serious. The ventilation process of tunnel with branch tunnel is simulated by CFD (Computational Fluid Dynamics) numerical simulation method. The variation of flow field and concentration field with time during construction period is studied under several typical working conditions, and the influence of vortex on air flow and harmful gas distribution in palm surface and branch tunnel is analyzed. When the air flow distribution channel is not smooth, the size and position of the vortex in the vortex area near the palm surface change periodically, and the influence range decreases gradually with the increase of ventilation time. The harmful gases and soot produced by tunnel blasting will move and spread with the flow of air flow, and will be gradually discharged out of the hole. Through the study of the exhaust process of air flow and harmful gas in the main tunnel and branch tunnel of the tunnel, it is concluded that the vortex zone is formed near the palm surface of the tunnel under the action of ventilation and at the intersection position between the branch tunnel and the main tunnel. The generation and change of the vortex continuously consume the mechanical energy of ventilation, reduce the ventilation efficiency, and cause a certain blocking effect on the drainage of harmful gases. The drainage process of harmful gases in the tunnel includes movement and diffusion. The CO is discharged outside the tunnel in the process of movement, and the peak value of CO in the tunnel is continuously reduced in the diffusion process. The time to reach the safe concentration in the tunnel under different working conditions is summarized, and some reference suggestions for the construction progress of the tunnel are given.
【作者单位】：西安理工大学西北旱区生态水利工程国家重点实验室培育基地;
【基金】：国家自然科学基金(51679197) 陕西省重点科技创新团队(2013KCT-015)~~
【分类号】：TV554

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