非伴煤瓦斯隧道施工危险度动态分级方法研究

Study on Dynamic Grading Method for Risk of Non-coal Gas Tunnel

在隧道工程中,真正有非伴煤瓦斯威胁的施工段落是短而少的,实现瓦斯灾害动态危险度等级管理对隧道瓦斯防治工作实际意义重大.提出了一种多指标综合分析判定隧道施工段落瓦斯危险度动态等级的方法,其基本指标包括:送抵施工掌子面的实际风量,施工掌子面和总回风断面处瓦斯浓度,超前地质钻孔及其残孔瓦斯浓度与压力,施工掌子面及其前方围岩岩性与构造面发育状态;辅助指标包括:已开挖洞身段的封闭情况,通风系统储备的通风能力等.方法的核心是综合分析隧道当前瓦斯涌出状态与能送抵掌子面的实际风量之间的配对关系.工程实例云顶山一号高瓦斯隧道算例表明,该方法是行之有效的.

Generally in a tunnel, non-coal gas construction passages with real threat are short and small, so treating differently gas states in different passages of the tunnel has important practical significance on gas prevention and control work of the tunnel. This paper introduces a method of determining dynamic level of gas risk of tunnel construction passages by multiple parameters. The basic parameters of the method includes： actual air volume sent to the tunnel face, gas concentration of total return air section or tunnel face, gas pressure and concentration of geological drilling and its residual hole, the tunnel face and the front wall rock lithology and structure plane development state. The auxiliary parameters of the method includes： closed condition of excavated tunnel, reserved ventilation capacity of the ventilation system. Its core is to comprehensively analyze the relationship of current tunnel gas emission state and actual air volume delivered to the tunel working face. The example of No. 1 high gas tunnel of Yundingshan shows that the dynam- ic grading method is effective.