特长隧道斜井施工段通风优化  

Optimization of ventilation in construction section of inclined shafts in extra-long tunnels

作　　者：王朋 潘红伟 程锋 贾润枝 贵珊 任锐[2] 龙葳 WANG Peng;PAN Hong-wei;CHENG Feng;JIA Run-zhi;GUI Shan;REN Rui;LONG Wei(The No.1Engineering Co.,Ltd of China Railway Beijing Engineering Group,Xi'an 710100,Shaanxi,China;School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China)

机构地区：[1]中铁北京工程局集团第一工程有限公司,陕西西安710100 [2]长安大学公路学院,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2023年第1期72-81,共10页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51978059;51908061)。

摘　　要：为解决特长隧道斜井施工段存在的主洞粉尘浓度高、作业环境差等问题,以中兰(中卫—兰州)铁路香山特长隧道工程为依托,在5#斜井施工段小里程方向开展现场测试,采集主洞内各测试断面的风速、风流方向和不同工况下的粉尘浓度,反映现场实际通风情况;利用Fluent软件建立斜井施工段压入式通风的三维数值模型,研究各作业工况下主洞内风流场特征和粉尘扩散规律;并结合通风数值计算,优化5#斜井施工段通风结构,提出相应改善措施。研究结果表明:原设计通风系统送风量不足,隧道洞身段平均风速较低,仅为0.1~0.2m/s,且在二衬台车处和主洞与斜井交叉口处存在大量涡流区,出渣作业和喷混作业产生的粉尘大量滞留在隧道主洞内,粉尘聚集现象明显;出渣作业时洞内粉尘浓度最高,可吸入式粉尘浓度和全尘浓度最大值为35.4和39.3mg/m^(3),喷混作业次之,立架作业时洞内粉尘浓度较低,可吸入式粉尘浓度和全尘浓度最大值为5.3和7.2 mg/m^(3),3种工况下洞内粉尘浓度均超过规范允许值且达到人体可呼吸到的高度;二衬台车处和斜井与主洞交汇处风流组织混乱,存在大量涡流区,粉尘颗粒在上述地点聚集,无法顺利排出洞外;针对上述问题,采用增设送风接力风机、射流引导风机和防尘帘等措施,增大风管送风量,提高隧道内回风风速,引导风流排出洞外。In order to solve the problems of high dust concentration and poor working environment in the construction section of the inclined shaft of the extra-long tunnel,field tests were carried out in the construction section of the 5#inclined shaft of the Xiangshan Super-long Tunnel of the Zhonglan(Zhongwei-Lanzhou)Railway.The wind speed,wind flow direction,and dust concentration of each test section were collected to reflect the actual ventilation situation.A three-dimensional numerical model of press-in ventilation in the construction section of the inclined shaft was established to study the characteristics of the ventilation flow field in the tunnel and the law of dust diffusion.Combined with the numerical calculation of ventilation,the ventilation structure was optimized,and corresponding improvement measures were proposed.The results show that the air supply volume of the originally designed ventilation system is insufficient,and the wind speed of the tunnel body is low,only 0.1to 0.2m/s.There are a large number of vortex areas at the second lining trolley and at the intersection of the main hole and the inclined shaft.A large amount of dust generated by slag extraction and shotcrete operations is trapped in the main tunnel,and the dust accumulation phenomenon is obvious.During the slag removal operation,the dust concentration in the cave is the highest,the maximum values of the inhalable dust concentration,and the total dust concentration are 35.4and 39.3mg/m^(3),followed by the spray mixing operation.The maximum values of inhalation dust concentration and total dust concentration are 5.3and 7.2 mg/m^(3).Under the three working conditions,the dust concentration in the cave exceeded the allowable value of the specification.The wind flow at the second lining trolley and the intersection of the inclined shaft and the main tunnel are chaotic,and there are a lot of eddy current areas,where dust particles gather and cannot be discharged out of the tunnel smoothly.In response to the above problems,measures such as addi

关 键 词：隧道工程 施工通风 现场测试 数值模拟 通风优化 

分 类 号：U453.5[建筑科学—桥梁与隧道工程]