供水工程瓦斯隧洞支护设计与施工

Support Design and Construction of Gas Tunnel for Water Supply Project

柴河供水工程有压供水隧洞在开挖阶段遇到瓦斯溢出,经瓦斯气体浓度的监测及涌出量理论计算定义为低瓦斯隧洞。在施工过程中通过对隧洞初期支护中的喷射混凝土添加气密剂调整喷射混凝土配合比及喷射工艺,型钢支撑减少焊接工艺,采用机械连接的方式,总结了更为合理的锚喷支护参数及施工工艺,保证隧洞在开挖、支护、衬砌阶段的施工安全。

The pressurized water supply tunnel of Chaihe water supply project encountered gas overflow during excavation,it is defined as low gas tunnel by monitoring the gas concentration and calculating the gas emission amount in this paper.In the process of construction,airtight agent is added to the shotcrete in the initial support of tunnel to adjust the shotcrete mix ratio and shotcrete technology,Steel bracing reduces welding process and adopts mechanical connection,and the more reasonable parameters and construction technology of bolting and shotcrete support are summarized to ensure the construction safety of the tunnel in the stage of excavation,support and lining.