高海拔隧道施工出碴车二次扬尘扩散规律  

Diffusion Law of Secondary Dust Caused by Ballast Truck in High Altitude Tunnel Construction

作　　者：孙三祥[1,2,3] 王文 李国良[5] 李雷[5] 李宁[5] SUN Sanxiang;WANG Wen;LI Guoliang;LI Lei;LI Ning(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China;Gansu Rail Transit Mechanical Application Engineering Laboratory,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China;Engineering Research Center for Cold and Arid Regions,Water Resource Comprehensive Utilization,Ministry of Education,Lanzhou Jiaotong University,Lanzhou Gansu 730070,China;Railway Power School,Shaanxi Railway Institute,Weinan Shaanxi 714000,China;Bridge and Tunnel Design Institute,China Railway First Survey and Design Institute Group Co.,Ltd.,Xi'an Shaanxi 710043,China)

机构地区：[1]兰州交通大学环境与市政工程学院,甘肃兰州730070 [2]兰州交通大学甘肃省轨道交通力学应用工程实验室,甘肃兰州730070 [3]兰州交通大学寒旱地区水资源综合利用教育部工程研究中心,甘肃兰州730070 [4]陕西铁路工程职业技术学院铁道动力学院,陕西渭南714000 [5]中铁第一勘察设计院集团有限公司桥梁隧道设计院,陕西西安710043

出　　处：《中国铁道科学》2022年第4期53-63,共11页China Railway Science

基　　金：甘肃省重点研发计划项目(17YF1GA010)。

摘　　要：为分析隧道内出碴车行驶时产生的二次扬尘对施工环境的影响并研究其扩散规律,依托采用钻爆法施工的敦格铁路某高海拔单洞单线特长隧道建立三维数值模型,并通过现场实测进行验证;以出碴车速度、隧道底面积尘负荷2个因素为变量,基于现场数据设置9种工况,对通风条件下出碴车在高海拔隧道中行驶产生的气流速度场和扬尘浓度场进行三维非稳态模拟;根据模拟结果,进行扬尘浓度与出碴车速度、底面积尘负荷扬尘浓度、扬尘浓度沿程分布的关系拟合。结果表明:出碴车行驶过程中,环隙流和尾部涡流是隧道底面积尘上扬扩散的主要原因;出碴车后部二次扬尘浓度与出碴车速度、隧道底面积尘负荷均呈沿程递增的二次函数关系;隧道底面积尘负荷一定时,自出碴车启动后25 s至驶出隧道的时段内,二次扬尘平均浓度沿程符合玻尔兹曼分布;出碴车速度、行驶时间是影响隧道内二次扬尘浓度分布的主要因素,确定合理的车速有利于缩小二次扬尘的扩散范围。To analyze the influence of secondary dust on the construction environment caused by the driving of ballast truck in tunnels and study the diffusion law,a 3D numerical model was established based on a high altitude single-hole single-line long tunnel constructed by drilling and blasting method in Dunhuang-Golmud Railway,and the model was verified through field measurement data.Taking the two factors of the speed of ballast truck and the dust load in tunnel bottom area as variables,the 3D unsteady simulation of the airflow velocity field and dust concentration field generated by the ballast truck driving in the high altitude tunnel under ventilation conditions were conducted by setting 9 working conditions based on the field data.According to the simulation results,the relationships between the dust concentration and the speed of ballast truck,the dust concentration of dust load in the bottom area,and the dust concentration along the distribution were fitted.The results show that annulus flow and tail eddy current are the main reasons for dust rising and diffusing in the tunnel bottom area during the driving of ballast trucks.The secondary dust concentration at the back of the ballast truck has an increasing quadratic function with the speed of the ballast truck and the dust load in the tunnel bottom area along the distance.When the dust load in the tunnel bottom area is constant,during the period from 25 s after the ballast truck starts to drives out of the tunnel,the average concentration of secondary dust is consistent with the Boltzmann distribution along the distance.The speed and driving time of ballast truck are the main factors affecting the distribution of the secondary dust concentration in the tunnel.Determining a reasonable speed is beneficial to reduce the diffusion range of secondary dust.

关 键 词：高海拔隧道 出碴车 二次扬尘 扬尘浓度 玻尔兹曼分布 

分 类 号：U453.5[建筑科学—桥梁与隧道工程]