岩溶隧道突泥机制与防治技术研究

Study on Mechanisms of Mud Bursting in Tunneling in Karst Areas and Its Prevention and Control

为规避和降低岩溶隧道的突泥风险,采用归纳分析方法总结岩溶与隧道的位置关系,基于力学分析方法揭示岩溶隧道的突泥机制和主要影响因素,并以贵都高速公路九条龙隧道突泥现场实例,对突泥事故原因、处理方案和防治措施展开论述。得出以下结论:1)岩溶与隧道的位置关系可划分为隧道周围存在岩溶、隧道整体穿越岩溶和隧道部分穿越岩溶3种类型;2)从宏观和微观2个方面揭示岩溶隧道的突泥机制,其宏观机制是指岩溶隧道不同的突泥类型,其微观机制是指地下水对地层的小尺度物理力学作用;3)针对岩溶隧道不同工程地质特征,应重视工程勘察和隧道施工作业中的超前预报,采用合理的开挖方法和超前支护措施,规范施工作业流程,预防岩溶隧道突泥事故的发生。

The position relationship between tunnels and karsts is summarized,so as to avoid or reduce the mud bursting risk in tunneling in karst areas.The mud bursting mechanisms and the major influencing factors are studied by means of mechanical analysis method.The causes,treatments and prevention and control methods of mud bursting are discussed,with the mud bursting in Jiutiaolong tunnel on Guiyang-Duyun highway as an example.Conclusions drawn are as follows：1） The position relationship between tunnels and karsts can be divided into 3 types,i.e.,there are karsts around the tunnel,the entire tunnel crosses karsts and part of the tunnel crosses karsts.2） The mechanisms of mud bursting in tunneling in karst areas are studied in macroscopic and microscopic manners.The macroscopic mechanisms of mud bursting refer to different mud bursting types,and the microscopic mechanisms of mud bursting refer to the small scale physical and mechanical effect of the ground water on the ground.3） The engineering investigation and the advance prediction during tunnel construction should be emphasized,rational excavation methods and advance support measures should be adopted and the construction process should be standardized on basis of the geological characteristics of tunnels in karst areas,so as to avoid mud bursting.