攀大高速公路宝鼎2号隧道施工通风方案研究

Construction Ventilation Scheme for the Baoding 2#tunnel of the Panzhihua to Dali Expressway

攀大高速宝鼎2号隧道为国内在建高瓦斯区段最长和穿越煤层最多的公路隧道,全线高瓦斯区段有4440 m,占比50.6%,说明施工通风将是宝鼎2号隧道修建的关键点和难点。通过调研资料并考虑实际工序组织,其通风方式为压入式与射流巷道式,根据瓦斯分布将隧道全线划分为十个工区,在考虑海拔高度影响下,分别计算各个工区的需风量和风管、隧道通风阻力后,进行轴流风机和射流风机选型,最终确定各个工区风机配置,优化各工区施工通风方案,确保在施工期间人员安全。实践表明,该工程通风方案是合理的,可为以后相似施工提供借鉴。

Baoding 2#tunnel of Panzhihua to Dalian Expressway is a highway tunnel under construction in China with the longest gas section and the most coal seams.The length of high gas section is 4440 m,accounting for 50.6%of the whole line,which indicates that construction ventilation will be the key and difficult points in the construction.Through the investigation materials and actual construction organizations,a combination mode of forced ventilation and jet flow gallery ventilation is adopted in Baoding 2#Tunnel.According to the gas distribution,the entire tunnel is divided into ten work areas.Considering the influence of altitude,the fresh air demand and ventilation resistance of each duct and tunnel are calculated respectively.Furthermore,we choose the axial fan and jet fan,and finally determine the fan configuration of each work area.Therefore,the construction ventilation scheme of each work area is optimized to ensure personnel safety.Practice shows that the construction ventilation scheme is reasonable and can provide reference for similar projects in the future.