深埋隧道填充型溶腔溃水机制及风险识别

Feature and risk identification of super karst water burst in deeply buried karst tunnel

结合国内外岩溶隧道修建过程中涌、突水灾害的特征分析,将大体量且有一定静储量的高压岩溶水瞬间释放,并伴随突泥、突巨石的特殊涌水定义为岩溶溃水;基于宜万铁路马鹿箐隧道特大岩溶溃水灾害分析,得到了岩溶溃水的基本特征,通过分析岩溶溃水的机理获得了构成岩溶溃水风险的几个主要因素;基于理论分析、数值模拟等方法,并结合现场工程经验,对岩溶溃水风险发生的几个门槛条件进行了初步的确定;针对溃水风险识别的实施方案,提出了超前水平钻探并结合放水试验和闭水试验的方法。

With the acceleration of tunnel construction, emerging issue of high-pressure karst water burst becomes more and more complex, and the study subject of analyzing and grasping its features and taking effective risk control measures is still a world-class long-standing puzzle. Based on the feature analysis of the karst water burst disaster during the construction of karst tunnels at home and abroad, the special water burst accompanied with high pressure water burst, earth burst and rock burst is defined as super karst water burst. With the analysis of super karst water burst which happened in Maluqing Tunnel of Yi- Wan Railway, five basic characteristics of super karst water burst are obtained, and its risk sources are also identified from the respects both of geology and human engineering activities. Based on the theoretical analysis, numerical simulation and on-site engineering experience, several threshold conditions for the occurrence of super karst water are identified. In response to implementation plan of risk identification, the method of advanced horizontal drilling with drainage test and closed water test is also proposed.