【作者】 李利平；

【导师】 李术才；

【作者基本信息】 山东大学 ， 工程力学， 2009， 博士

【摘要】 在岩溶地区修建隧道、矿山以及水电站等地下工程时,经常遇到突水、涌泥等大型地质灾害,轻则冲毁器具、贻误工期,重则造成人员伤亡和重大经济损失。随着我国西部大开发战略的实施,大型突水地质灾害逐渐成为制约我国地下空间建设发展的瓶颈问题。本文以湖北沪蓉西高风险岩溶隧道为研究对象,通过物理模型试验、现场试验、非线性突变理论以及数值计算等手段,深入研究岩溶突水的灾变演化过程及其力学机理,分析了突水通道的形成机制及其突变模型,提出了岩溶突水防治技术体系,取得了一系列有意义的研究成果。首先,基于大型突水资料的系统收集与分析,从含导水构造能量储存、岩溶水动力扰动和能量释放以及含导水构造系统失稳角度提出了突水的发生条件,将突水影响因素划分为地质因素和工程因素,基于防突结构的破坏模式将突水类型划分为地质缺陷式与非地质缺陷式两类。通过对不同突水模式普遍特征的分析,将岩溶突水过程划分为蓄势与失稳两个显著阶段,并采用多场耦合软件COMSOL计算了开挖条件下突水形成过程的流态演变特征,实现了岩溶水由含水层中的渗流发展为潜在突水通道中的快速流,最后突入隧道内形成自由流的灾变演化过程。就非地质缺陷式突水,分别研究了突水通道形成的微观作用机制和突水突变模型的宏观力学判据。采用弹脆性损伤模型推导了渗流对隧道围岩稳定性影响的理论解,给出了围岩失稳突水的判据,并借助Flac3 D fish语言将理论推导程序化,分析了渗流作用下隧道开挖卸荷的损伤机制。同时,采用可考虑渗流-损伤耦合机制的RFPA软件包,分析了强渗流作用下隧道围岩裂隙萌生、扩展、贯通直至突水通道形成的演化过程,从围岩多场信息的演变角度揭示了非地质缺陷式突水通道形成的灾变机制;将防突层概念引入深埋层状灰岩隧道的突水模型中,建立了防突层失稳的尖点突变和双尖点突变模型,分析了不同防突层静力与动力失稳的非线性突变特征,给出了失稳判据与最小安全厚度值的计算公式,并结合有限差分程序,分析了动载峰值、频率以及水压大小对防突层最小安全厚度的影响。最后,结合隧道突水工程实例,验证了最小安全厚度计算公式的有效性,并结合考虑渗流-损伤的数值计算结果,进一步证实了渗流-损伤诱发防突层破断突水的微观作用机制。开展防突层失稳突水的相似物理模型试验,进一步研究非地质缺陷式突水的灾变机制。基于三维固流耦合相似理论的分析,研制了新型固流耦合相似材料,采用研制的试验台架和光纤监测系统开展隧道涌水和矿井采区突水的相似模型试验,就应力、位移、渗流以及地球物理信息场的演化特征进行了全方位监测,分析了开挖扰动下防突层持续的渗流-损伤诱发围岩局部涌水与整体失稳突水的灾变演变机制,揭示了岩溶突水多场信息的突跳特征,并验证其宏观力学判据的有效性,试验结果与数值计算结果具有很好的一致性。就地质缺陷式突水,基于不同成因地质缺陷体的归类和阻水性能分析,提出地质缺陷诱发突水的两种典型灾变模式,分析了地质缺陷式突水通道的形成过程及其失稳的力学判据。就不同尺度地质缺陷体渗透特性的差异,建立了强渗流作用下充填介质的渗透失稳模型和充填体的滑移失稳突水模型,并将之应用于齐岳山隧道岩溶管道诱发突水的实例分析中,结合数值分析结果,揭示了充填介质渗透失稳形成堵塞体后整体滑移突水的灾变演化过程;对于非导水断层,考虑两区段充填介质的力学属性,引入水致弱函数反映强渗流对断层充填介质的活化作用,建立了断层充填体滑移失稳的燕尾突变模型,并基于灾变演化路径控制参数的分析提出相应的防治措施。基于大量数值计算结果,分析了断层活化诱发破裂通道的灾变机制,给出了断层突水的4种灾变路径,并对断层参数对突水的敏感性进行了分析。最后,基于不同揭露型突水模式的灾变分析,提出复合式突水类型,分析地质缺陷诱发隔水围岩失稳的非揭露型突水的灾变机制,并结合工程实例,进一步揭示了断层活化导通暗河水涌入与隧道存在水力联系的充填型溶腔,并导致隧道拱部完整围岩压裂突水的灾变演化机制。最后,基于不同突水类型的通道形成机理与灾变力学模型的研究,依托沪蓉线两座控制性高风险岩溶隧道,建立了岩溶突水防治技术体系,从预防与治理角度首次提出岩溶隧道施工突水灾害综合预报预警关键技术。基于该体系指导原则,对齐岳山隧道和乌池坝隧道进行突水风险等级划分,并在乌池坝隧道开展了综合物探法探水试验与突水灾害预警演练。同时,结合该体系突水治理原则,研制高压大流量注浆设备和新型化学注浆材料,并开展浆材优选试验与原位注浆试验,在齐岳山隧道多处突水治理试验中取得了良好效果。试验结果与应用效益证明该体系具有很高的实用性与高效性。更多还原

【Abstract】 During the construction of underground engineering in serious karst area, geologica hazard of water inrush and mud outburst often occur in tunnel and other underground engineerings,which ofter lead to equipment destroyed and construction period bungled,even serious casualty and economic loss.With western development,large scale disaster of water inrush has gradually become the bottleneck problem of underground engineering development.In order to know the passage formation modle and instability mechanism,similar model test,field test,nonlinear catastrophe theory and numerical simulation have been done for the mechanism of water inrush and its prevention measures,and the technical system of water inrush prevention and control has been put forward,consequently series of meaningful research achievements has been obtained.Firstly,according to the analysis results of large scale disasters of water inrush,the occurrence conditions has been put forward from the view of energy storage of water bearing structure,dynamic zone of karst water and energy release, and system instability of water bearing structure,and influencing factors of water inrush includes geological factors and engineering factor,the microscopic and macroscopic characteristics has been analyzed,the water inrush can be divided into two types induced by geological defects or not.Based on the common characteristics of different water inrush types,the process of water inrush has been divided into energy storge stage and instability stage,the characteristics of fluid state has been simulated by COMSOL for the process of water inrush induced by excavation,numerical results show that the fluid state process of water inrush can be divided into Darcy in the aquifer firstly,Brinkman in the potential passage of water inrush secondly and N-S in the tunnel lastly.For the water inrush induced by instability of key aquifuge,the formation mechanism of water inrush passage and its instability criterion has been studied from microscopic and macroscopic viem.The analytical solution for tunnel stability with the seepage and its instability criterion has beenderived through the elastic-brittle damage model,and damage mechanism induced by seepage and dynamic excavation has been analyzed by the self making language of Flac 3D fish. The catastrophe evolution of water inrush passage has been simulated by RFPA for the crack initiation,propagation,coalescence and passage formation induced by seepage damage,and the catastrophe mechanism of water inrush passage formation for fractured rock mass has been presented from view of the multi-field information evolution;The concept of key aquifuge has been adopted for the water inrush model of deep bueied tunnel of layered limestone,the cusp catastrophe and double-cusp catastrophe model of key aquifuge has been established for static and dynamic instability,and its nonlinear catastrophe characteristics has been futher studied,so the instability criterion and calculation formula for minimum safety thickness of rock mass has been obtained.In addition,numerical simulation has been done in order to know the relationship between safety thickness of rock mass for water inrush preventing and blasting factor,water pressure and so on.Finally, the calculation formula for minimum safety tickness has been proved by the tunnel engineering example of water inrush,and the instability mechanism of key aquifuge induced by sustained coupling effect of seepage and damage evolution combined with the numerical results.Further study has been done by similar model test for water inrush mechanism induced by seepage damage.Based on the analysis on similarity theory of 3D solid-fluid coupling,the new similar material of solid-fluid coupling has been found,and similar model test for water infow of tunnel and water inrush of mining area has been done by self-developed extensible 3D test bench and optical fiber monitoring system,the evolution mechanism of water inflow and water inrush induced by seepage damage has been analyzed by the monitoring results of multi-field information,the simultaneous sudden jump phenomenon of stress, disppacement,seepage pressure and other information has been analyzed,and the macroscopic instability criterion has been proved again,the conclusions have also been proved by numerical results.For the water inrush induced by geological defect,two typical catastrophe models has been put forward according to analysis on seepage properties and classification of different geological defect,and the formation mechanism of water inrush passage and its instability criterion has been studied from microscopic and macroscopic viem.Based on the further analysis on seepage properties difference for geological defect of different scale,the instability mechanism of filling medium induced by seepage effect and water outburst model induced by blocking body of karst conduit has been studied,and the water inrush mechanism of Qiyueshan has been interpreted by the model application induced by karst conduit of filing type during the reainfll period combined with the numerical results;For the water inrush induced by water non-conductive fault,the catastrophe model of swallow tail style has been estabilished considering the mechanical effect of two section filling medium and its seepage properties differences,and corresponding countermeasure has been put forward according to the analysis of modle control parameters.In addition,the catastrophe mechanism of rupture passage induced by fault activation has been further studied by a series of numerical results considing the seepage damage,four types of water inrush evolution passage has been put forward and the analysis on influence parameters sensitivity for water inrush induced by fault has been done.Finaly,based on the water inrush mechanism of different type,compound modle of water inrush has been put forward and its disaster mechanism has been done for the water inrush passage composed of activation fault,karst conduit of filling medium and rock mass preventing water.Finaly,based on the research results of passage information and instability mechanism for different type of water inrush,the technical system of water inrush prevention and control has been established for engineering practice of two high-rish karst tunnel in Hurong highway,and key technology of comprehensive predition and early-warning for geological hazards during tunnel construction in high-rish karst areas has been put forward firstly.Based on guiding principle of this systm,new grouting equipment of high pressure large volume and chemical grouting material has been developed,and lots of field tests have been done in two karst tunnels,such as rsik grade division in Qiyueshan tunnel and Wuchiba tunnel, karst aquifer detection by comprehensive geophysical method and warning maneuven for water inrush disaster in Wuchiba tunnel,grouting treatment of water inrush in Qiyueshan tunnel.The practicality and high effectiveness has been proved by the lots of filed test results and application benefit.更多还原