高海拔隧道施工期污染物扩散规律  

Pollutant diffusion law during high-altitude tunnel construction

作　　者：陈星宇 吴剑[2] 任松[1] 张平[1] 邓超[1] 孔令伟 CHEN Xingyu;WU Jian;REN Song;ZHANG Ping;DENG Chao;KONG Lingwei(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;China Railway Southwest Research Institute Limited Company,Chengdu 611731,China;Zhaotong Zhaolu Expressway Investment and Development Limited Company,Zhaotong 657000,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]中铁西南科学研究院有限公司,四川成都611731 [3]昭通市昭泸高速公路投资开发有限公司,云南昭通657000

出　　处：《浙江大学学报（工学版）》2024年第1期176-187,共12页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(52074048)。

摘　　要：为了探究高海拔隧道施工通风过程中的污染物扩散规律,依托川藏铁路芒康山隧道工程,采用数值模拟和现场测试的方法,研究高海拔隧道施工通风过程中粉尘和CO的扩散规律.研究结果表明,粉尘主要是以贴壁流动的形式向洞外扩散,在该过程中会聚集成为“粉尘团”.粉尘扩散主要是受到重力影响发生沉降,隧道内风速过大,不利于降低粉尘质量浓度.CO以“气团”的形式从掌子面附近向洞口迁移,在迁移过程中CO气团体积逐渐扩大,质量浓度峰值不断下降,逐渐形成“U形”的分布趋势,CO质量浓度的现场测试结果与数值模拟结果基本吻合.随着海拔高度的上升,隧道内的CO质量浓度会增大,隧道内同一位置CO质量浓度达到规范要求的时间会增加.推导基于海拔高度的隧道通风过程中CO质量浓度修正系数计算公式,对当前规范中CO的海拔高度修正系数进行很好的补充.Numerical simulation and on-site testing methods were used to analyze the diffusion law of dust and CO during the ventilation process of high-altitude tunnel construction by relying on the Mangkang Mountain Tunnel Project of the Sichuan Tibet Railway in order to analyze the diffusion law of pollutants during the ventilation process of high-altitude tunnel construction.Results show that dust mainly diffuses towards the outside of the tunnel in the form of wall-adhering flow,and it accumulates into‘dust clusters’during this process.Dust diffusion is mainly influenced by gravity and causes sedimentation.Excessive wind speed in the tunnel is not conducive to reducing dust mass concentration.CO migrates in the form of‘air masses’from the vicinity of the palm face to the entrance of the cave.The volume of CO air masses gradually expands during the migration process,and the mass concentration peak continuously decreases,gradually forming a‘U-shaped’distribution trend.The on-site test results of CO mass concentration basically accorded with the numerical simulation results.The CO mass concentration in the tunnel will increase as the altitude increases,and the time it takes for the CO mass concentration at the same location in the tunnel to meet the standard requirements will increase.A formula for calculating the correction coefficient of CO mass concentration during tunnel ventilation was derived based on altitude,which is a good supplement to the altitude correction coefficient of CO in the current specifications.

关 键 词：高海拔隧道 通风 污染物扩散 现场测试 修正系数 

分 类 号：X947[环境科学与工程—安全科学]