通省特长公路隧道施工过程通风数值模拟分析

Numerical Simulation Analysis of Ventilation During Construction of Extra Long Highway Tunnel Across the Provinces

为了研究特长公路隧道因施工通风受隧道所在海拔、施工方法、通风方法、施工工期要求等所面临问题,并提出解决方案,采用数值模拟方法对通省特长公路隧道施工过程中使用的巷道式通风和竖井扩挖通风方案展开研究。结果表明:巷道式通风时,爆破后通风10 min即可进入掌子面工作区进行施工,满足快速施工的要求;竖井扩挖不同深度时,CO在竖井扩挖空间的分布呈现峰值特性,且随着通风时间的增加,峰值位置逐渐向井口移动;在相同的通风风量下,通风7 min后工作面附近的CO浓度就已降至安全卫生标准以下。

In order to study the problems faced by the construction ventilation of extra long highway tunnel due to the altitude of the tunnel,construction method,ventilation method and construction period requirements,and put forward solutions,the tunnel type ventilation and shaft expansion ventilation scheme used in the construction process of across provinces extra long highway tunnel are studied by using numerical simulation method.The results show that:during the tunnel ventilation,after blasting it s allowed to enter the face working area for construction 10 minutes ventilation,to meet the requirements of rapid construction;when the shaft is expanded at different depths,the distribution of CO in the space of shaft expansion presents peak characteristics,and with the increase of ventilation time,the peak position gradually moves to the wellhead;under the same ventilation volume,after 7 minutes ventilation the CO concentration in the vicinity of the working face was reduced to below the safety and health standard.