摘要
为研究隧道钻爆法施工产生的有害气体压入式通风效果,以我国成兰铁路跃龙门隧道工程为依托,通过建立独头隧道内气体湍流流动与浓度扩散有限元模型,模拟风机出口风速13.2 m/s时,掌子面爆破作业后爆生有害气体的扩散过程,研究了不同风管布设位置与施工方法下CO浓度场时空演化规律。研究结果表明:掌子面CO浓度随通风时间呈负指数下降,CO浓度在300~900 s内到达浓度限值。对比各风管布设位置,风管拱顶布设时通风效果最好,通风600 s内CO浓度可降低至浓度限值。对比各施工方法,台阶法施工下通风350 s内CO浓度可降低至浓度限值,同时该隧道结构能够避免通风前期的CO滞留现象。
To explore the forced ventilation effect of the harmful gas produced by drill-blast construction,a finite element model is established to show gas turbulent flow and concentration diffusion in a one ended tunnel,based on the Yuelongmen tunnel project of Chenglan railway in China.When the wind speed at the exit of the simulated fan is 13.2 m/s,the diffusion process of the harmful gas produced by blasting at the working face of the tunnel is simulated.Meanwhile,the temporal and spatial evolution law of CO concentration field for different positions and excavation modes of the air duct is studied.The results show that CO concentration at the working face decreased negatively with the ventilation time,and the CO concentration reached the concentration limit within 300~900 s.Comparing the layout position of each air duct,the ventilation effect is best when the duct arch is laid,and the CO concentration within 600 s of ventilation can be reduced to the concentration limit.Comparing the construction methods,the CO concentration in the 350 s ventilation under the bench method can be reduced to the concentration limit.At the same time,the tunnel structure can avoid the CO retention phenomenon in the early stage of ventilation.
作者
朱应伟
章光
胡少华
罗忆
蒲青松
ZHU Ying-wei;ZHANG Guang;HU Shao-hua;LUO Yi;PU Qing-song(School of Safety Science and Emergency Management,Wuhan University of Technology,Wuhan 430070,China;Hubei Key Laboratory of Roadway Bridge and Structural Engineering,Wuhan University of Technology,Wuhan 430070,China;China Railway Fifth Bureau Group Co Ltd,Changsha 550003,China)
出处
《爆破》
CSCD
北大核心
2020年第1期126-133,共8页
Blasting
基金
武汉理工大学自主创新研究项目(2019-zy-302)
国家自然科学青年基金项目(51609184)
国家自然科学基金资助项目(51779197)。
关键词
压入式通风
风管布设
施工方法
CO浓度
扩散规律
forced ventilation
ventilation layout
construction method
CO concentration
diffusion law