华北二叠系泥岩隧道灾变机理及控制研究

Research on Disaster Mechanism and Control of Permian Mudstone Tunnel in North China

针对太岳山隧道穿越华北二叠系紫红色泥岩段施工过程中发生的影响工程进度的地质灾害问题,对太岳山泥质岩隧道存在的地质灾害的关键性致灾因子以及其相互作用进行了理论分析,结合现场施工状况及工程处治实践,对支护措施选取及效果进行评价。研究结果表明,泥岩隧道存在四大主要致灾因子,分别为地质因子、岩体结构性质因子、水文因子以及施工因子,其中,施工开挖揭穿软岩界面导致岩体结构破碎和高地应力调整释放,地下水沿岩体裂隙流通,软岩遇水泥化从而强度迅速劣化是导致这种协同破坏机制的根本原因。解决泥岩隧道崩塌、大变形灾害的根本途径在于:采取合理的设计、施工及支护方法,尽量避免内部致灾因子的剧烈作用造成协同灾害效应,最终实现软岩中水岩动力系统平衡状态的平稳过渡。

To solve the problem of geological hazards during the construction of the Taiyueshan tunnel which crosses the permian purple mudstone section in North China,a theoretical analysis of key hazard factors and their interrelationships with geological disasters were analyzed.On-site construction and engineering treatment practices were combined to evaluate tunnel supporting measures and their effects.The research results show that the four main hazard factors in mudstone tunnels are geology,rock structure properties,hydrogeology and construction.The construction excavation through the soft rock interface led to the breakage of the rock mass structure and the adjustment,and released high ground stress.The basic way to solve the collapse and large deformation disasters of mudstone tunnels is adopting reasonable design,construction and support methods,and avoiding the violent adjustment of the internal disaster-causing factors as possible.With these measures,the smooth transition of the equilibrium state of the water-rock power system in the soft rock could be achieved.