大纵坡双洞隧道互补式通风运营测试

为解决大纵坡双洞隧道风量不平衡时, 上坡隧道是否需要设置通风井的技术问题, 以大别山公路隧道为实体工程, 现场检测了互补式网络通风隧道内CO浓度、烟雾浓度和风速, 分析了大纵坡隧道采用的双洞互补式网络通风方式中换气通道的作用和存在的问题。测试结果表明: 互补式网络通风能够满足隧道内污染物浓度控制要求; 2个换气通道能起到气流双向交换的作用, 交换风量满足设计要求, 互补式通风方案可行; 上下行隧道通风负荷不平衡, 对于纵坡较大的特长隧道, 可以采用互补式通风, 取消其上坡隧道的通风井。

Complementary ventilation operational test in large longitudinal slope double-hole tunnel

In order to solve the technical problem that whether ventilation shafts are needed to set up or not in upstream tunnel when the air inflow and outflow are imbalanced in the large longitudinal slope double-hole tunnel, Dabie Mountain Highway Tunnel was selected as an entity engineering for analysis.The CO concentration, visibility index, and air velocity in the complementary network ventilation tunnel were tested on site, and the effect and existing problem of ventilation channel in the double-hole complimentary network ventilation system were analyzed.Test result indicates that the complimentary network ventilation can meet the control criteria of contaminant concentration.Two ventilation channels can play the role of airflow bi-direction exchange, and the exchanged air volume can meet design requirement, therefore, the complementary ventilation plan is feasible.When ventilation loads in upstream and downstream tunnels are imbalanced, the complementary ventilation can be used instead of ventilation shaft in upstream tunnel for large longitudinal slope extra-long tunnel.