深长隧道充填型致灾构造渗透失稳突水突泥机理研究

The long deep tunnels with large embedded depth, long tunnel line, high ground stress, high osmotic pressure and filling disaster-induced structures features have become the key point and difficult for national infrastructure construction. During the construction of deep long tunnels, the filling disaster-induced structures are often encountered, resulting in water and mud inrush occurred frequently. The filling disaster-induced structures have the characteristics of accompanied invisibility, hysteretic nature and catastrophic ability. The primary reason for these disasters is that the complex mechanical mechanism of water and mud inrush is unclear and lack of effective identification and forecast methods. Cases investigation, Geological survey，theory analysis, numerical simulation based on PFC software and permeability experiment are make use of study the features of filling disaster-induced structures and catastrophe model from the point of macro geological analysis-filling medium damage characteristics-filling type structure instability of water inrush, geological occurrence characteristics of filling disaster-induced structures would be revealed and the particle losses law and the seepage failure mechanism under seepage-erosion-stress coupling would be proposed. By obtaining the critical threshold of multi omen information. It can provide support for improving the accuracy of the early warning water hazard prediction of filling disaster-induced structures instability. As discrimination and forecast for infiltration instability, mud and water inrush disaster caused by filling disaster-induced structures supported by theoretical methods. Research achievements will be provide a significant and practical method to prevent water and mud inrush in underground engineering.

随着国家重大基础建设的发展，具有“大埋深、长洞线、高地应力、高渗透压和致灾构造复杂”特点的深长隧道成为施工建设的重点和难点。隧道建设过程中经常遭遇充填型致灾构造，造成突水突泥灾害频发，且灾害具有隐蔽性、滞后性和强致灾性的特点，其难以遏制的根本原因是由于对其复杂的灾变机理认识不够，难以形成有效的判识预测方法。本项目采用案例调研、地质调查、理论分析、颗粒流数值模拟、充填介质渗流特性试验等手段，从宏观地质分析-充填介质破坏特性-充填型构造失稳突水突泥角度，研究隧道充填型致灾构造渗透失稳灾变演化机理。揭示深部充填型致灾构造的充填特性与灾变模式，提出充填介质的颗粒流失机制与破坏特性，揭示渗流-侵蚀-应力耦合作用下充填型致灾构造渗透失稳灾变演化机理，为提高充填型致灾构造渗透失稳突水突泥灾害判识预测提供理论支撑，研究成果对于地下工程重大水害防治具有重要科学意义与工程实用价值。

随着国家重大基础建设的发展，具有“大埋深、长洞线、高地应力、高渗透压和致灾构造复杂”特点的深长隧道成为施工建设的重点和难点。隧道建设过程中经常遭遇充填型致灾构造，造成突水突泥灾害频发，且灾害具有隐蔽性、滞后性和强致灾性的特点，其难以遏制的根本原因是由于对其复杂的灾变机理认识不够，难以形成有效的判识预测方法。本项目采用案例调研、地质调查、理论分析、颗粒流数值模拟、充填介质渗流特性试验等手段，从宏观地质分析-充填介质破坏特性-充填型构造失稳突水突泥角度，研究隧道充填型致灾构造渗透失稳灾变演化机理。a通过大量国内外突水突泥案例资料的系统收集与整理分析，划分了四种典型突水突泥灾害类型，提出了突水突泥灾害的典型地质模式：灾害源、突水通道和阻水隔泥构造，揭示了典型突涌水灾害源的赋存特征，建立了突涌水灾害源孕灾性判识指标体系和属性识别模型。b建立了充填体颗粒渗流基本模型，推导了充填体内部可动颗粒流失量的表达式，揭示了孔隙流速与孔隙率和渗透系数的表征关系；c建立了宾汉型泥水混合流体的本构方程，揭示了其在管道内流速分布规律和压降流量关系；基于基于赫斯特罗姆 (Hedstrom) 准数推导了泥水两相混合流体的临界流速，建立了泥水混合流体从层流向过渡的流态判别准则。（3）根据充填介质的粒度分布特征和胶结状态，将充填介质分为砂砾型、泥砂型和粘土型3种类型。研制了应力-渗流耦合三轴渗透试验系统，系统分析了不同类型充填介质的渗透特征，揭示了充填介质涌水型、渗透型和滑移型3种典型渗透破坏模式，得到渗流-侵蚀-应力耦合作用下充填型致灾构造渗透失稳灾变演化机理。项目研究成果可为提高充填型致灾构造渗透失稳突水突泥灾害判识预测提供理论支撑，研究成果对于地下工程重大水害防治具有重要科学意义与工程实用价值。