新疆某深埋长引水隧洞有害气体成因分析及防治

Cause Analysis and Prevention of Harmful Gases in a Deep and Long Diversion Tunnel in Xinjiang

针对新疆某深埋长引水隧洞敞开式TBM施工中存在的有害气体逸出现象,为预防和减轻有害气体对施工进程和人员设备安全的不利影响,通过现场调查,开展现场气体浓度检测以及地质条件分析等提出了针对性强的施工处理措施,以控制有害气体浓度符合安全施工标准。根据隧洞附近的地质条件,初步判断隧洞出现的有害气体属于早期成岩气,在其沉积成岩过程中形成了有害气体,积聚在深部地层中。该隧洞逸出的有害气体主要为一氧化碳和甲烷气体,建立健全安全监测系统、优化通风系统和相应施工措施准备及预防可以有效减轻有害气体的影响。

In view of the phenomenon of harmful gas escaping in the open TBM Construction of a deep and long diversion tunnel in Xinjiang,construction treatment measures with strong pertinence are put forward through field investigation.It is aimed to prevent and reduce the adverse impact of harmful gases on the construction process and the safety of personnel and equipment and to control the concentration of harmful gas in accordance with the safety construction standards.According to the geological conditions near the tunnel,it is preliminarily judged that the harmful gas in the tunnel belongs to the early diagenetic gas,which was formed in the process of sedimentary diagenesis and accumulated in the deep stratum.The harmful gases emitted from the tunnel are mainly carbon monoxide and methane.Establishing and improving safety monitoring system,optimizing ventilation system and preparing and preventing of corresponding construction measures can effectively reduce the impact of harmful gases.