深埋隧道钻爆法开挖段突涌水灾害的形成机制及防控研究综述

Review of the evolution and mitigation of the water-inrush disaster in drilling-and-blasting excavated deep-buried tunnels

深埋隧道具有地应力高、渗透压大和灾害源广等特点,突涌水工程灾害风险较大,部分工段多采用钻爆法开挖。深埋隧道钻爆法开挖段突涌水成灾机制较为复杂,具有隐蔽性、复杂性、突发性和破坏性的特点,现有相关理论和技术研究存在着灾害源探测及辨识不明、突涌水灾害形成机制认识不清、恶性灾害预防控制不力等问题,已不能完全适用,工程灾害防控成为亟待解决的关键科技难题。从深埋隧道钻爆法开挖段突涌水的灾害源探测、成灾机制和灾害防控三方面对现有研究进行剖析,对深埋隧道钻爆法开挖段突涌水灾害研究的重点和方向提出三点建议:第一,要探明不良地质体和围岩结构,需要基于相对成熟的技术成果,结合实际工况融合多种超前地质探测方法,动态补探,充分吸收大数据强大的分析能力进行关联分析、模式识别,逐渐逼近"真解",做到定量化、精确化探测,形成多方法多设备的综合超前地质预报技术体系;第二,从能量储存与释放的角度建立灾害源的灾变模式,揭示突涌水灾害的发生条件和突发机制,发展隔水隔泥层安全性计算方法,将现有研究成果应用到实际工程方面;第三,要做到突涌水灾害的准确预警和有效控制,需要研究建立针对深埋隧道钻爆法开挖段的风险评估理论,根据隧道洞内围岩及其上覆岩层地质条件,将不同的治水技术有机结合起来,以求实现技术、经济、资源和环境利益的最大化。

The deep-buried tunnel has the characteristics of high in-situ stress,high osmotic pressure and rich sources of disasters.These factors can significantly increase the risk of water-inrush.Drilling-and-blasting excavation method must be adopted in some sections.The water-inrush in drilling-and-blasting excavated deep-buried tunnel are commonly characterized by concealment,complexity,suddenness and destructiveness and the disaster mechanism is more complicated.There are still some problems in the existing researches,such as the detection and identification of disaster source are inaccurate,the constructed disaster mechanism is unclear,the prevention and control of malignant disasters are inadequate.The existing theories and technologies are not fully applicable anymore,thus,the prevention and mitigation of geological hazards are the key scientific issues remained to be solved.The existing research status are analyzed from three aspects:the advanced geological prediction,the disaster mechanism of water-inrush,and the evolution and mitigation of constructed disaster.Three suggestions were put forward about the key points and directions of the research on the water-inrush in deep tunnel.First of all,it is necessary that comprehensive application of big data analysis and the latest research results of other subjects in order to achieve quantitative and accurate detection.Furthermore,the catastrophic model of disaster sources should be established from the perspective of energy storage and release.The occurrence conditions and emergency mechanism of engineering disasters need revealing.In addition,the method of calculating the safety of impermeable silt layers should be developed and the existing research results also should be applied to practical engineering.Last but not least,the risk assessment theory of the water-rich soft rock section of deep-buried tunnel should be studied seriously.According to the actual conditions of the tunnel,the different technologies of disaster control should be combined organically to maximize the benefits of technology,economy,resources and environment.