【作者】 朱超；

【导师】 许兆义；

【作者基本信息】 北京交通大学 ， 道路与铁道工程， 2011， 博士

【摘要】 地质环境为隧道工程的自然载体,其地质构造、岩土介质、地应力和水文地质等因素不仅控制着工程地质灾害的规模、频率与发育特征,而且直接影响隧址区的地面稳定性、深部稳定性、山体稳定性和围岩稳定性。因此,为了确保隧道工程的稳定,保障工程安全施工,必须就地质环境问题,开展系统而深入的研究。本文以在建的复杂滇西山区大瑞铁路罗家村隧道工程为依托,采用现场工程地质调查、现场监测和地质探测、理论分析和数值计算等方法,全面、系统地研究了罗家村隧址区的地质断裂、节理分布和工程特征,通过地质分析建立了数值计算模型,模拟计算了隧道进口段在开挖条件下对坡体稳定性的影响,探讨了隧道山体开裂的成因,并针对其地质环境的特殊性制定施工方案确保工程稳定安全。论文的主要研究成果如下：1.采用节理测线法调查罗家村隧道围岩节理发育特征,统计分析结果表明隧道围岩发育走向NW倾向SW230°,走向NE倾向NW310°及走向NE倾向SE130°的三组优势节理面,其中NW向节理发育极为密集,对隧道围岩危害最大。且无论是从小的尺度范围,还是从大的尺度范围,各组节理面分布都表现出一定程度的等距性和韵律性。2.通过大量的现场试验和工程实践,得到三维地震波追踪技术探测不同力学机制断层破碎带的经验图谱,提出了三维地震波追踪探测断层破碎带性质的判别准则,在此基础上建立了定量预测围岩质量分级的方法。并配合地质调查,超前水平钻探及红外探水的综合探测方法分析隧道地质环境,研究表明隧址区地质环境极为复杂,断裂构造纵横交错。探测结果与实际开挖情况基本一致,结论准确,可靠度较高。3.采用有限元强度折减法建立计算模型对隧道施工过程中坡体抗滑稳定状态进行动态模拟,得到的坡体抗滑稳定安全系数的变化曲线表明隧道开挖对坡体稳定性影响较大,在隧道开挖进尺20-45m区段影响最为明显。隧道安全穿越进口段坡体,不会导致坡体的滑移破坏。4.隧道山体开裂成因综合分析表明泥岩特殊的工程地质性质为山体开裂提供了物质基础；发育复杂的断裂构造在岩体内形成的纵横交切的软弱结构面是山体开裂的先决条件；隧址区单斜构造形成的高差和坡度,为山体开裂提供了足够大的重力势能和载体；而横向沟谷的深度切割为岩体开裂提供了空间和临空面。在隧道工程开挖触发条件下,岩体在自重应力、卸荷作用下,应力释放,而后岩层应力重新调整,产生沉降和倾向沟谷的倾倒拉裂,而裂隙与岩体中极为发育的节理完全贯通,则最终导致山体横向和纵向的开裂。5.监测了隧道拱顶沉降和洞周收敛,并分析了监测数据,结果表明依据特殊地质环境条件设计的施工方案合理,隧道工程结构稳定。更多还原

【Abstract】 Geological environment is vital natural environment vector for tunnel engineerings, which controls geological disasters’ scale, frequency and the development trend, and effects seriously the stability of region and ground surface and deep part and mountain and wall rock in the tunnel zone by means of geological structure and rock soil media environment and crustal stress and hydrogeology. Therefore, geological environment issue must be researched on systematically and in depth to ensure tunnel engineerings’ stability and construction safety.Based on above ananlysis, this paper, via construction of LuoJia Village tunnel of DaLi-RuiLi railway in western YunNan mountainous area, is intended to systematically study on faults and joints distribution and engineering features by kinds of methods such as geological survey and predication and monitoring at site and theoretical analysis and numerical calculation. The numerical calculation model is established to analyze tunnel excavation’s influence on mountain body stability. It is to be conferred on mountain body cracking cause of formation and special construction scheme for engineering safety. The main research work and accomplishment of the paper are generalized at follows:Statistic investigations and analysis of joints show that there are three preferred joints planes with SW and SE and NW tendency. Their distribution is equidistant and cadenced metrical. The joints planes with SW tendency is so compressed that they are worst for wall rock.The experienced maps of fault zones with different mechanical mechanism are gained by 3D seismic waves tracking technology based on lots of field test and engineerings practice. The criterions are established for different mechanical property faults and predication surrounding rock mass classification quantitatively. Overall analysis on geological environment with 3D seismic waves tracking technology and infrared waterprospecting and drilling is consistent with excavation results.Calculation model is setted up to dynamically simulate the anti-slide stable state of slope body by Strength Reduction FEM. It shows that the slope body stability changes obviously as long as the tunnel excavation between 20m to 45m based on safety coefficient variation curve. The tunnel can pass through the slope body safely without landslide failure. Mountain body cracking cause of formation includes landform and physiognomy factor and geological structure factor and rock soil media factor and tunnel excavation evoking factor. Mudstone with special engineering geology property is the material base; The complex geological structure with lots of faults is precondition; There are enough gravitational potential energy because the single anticline structure leads to enough discrepancy in elevation and inclination. There are enough space and free surfaces for mountain body cracking with latitudinal valleys deep incision. Stress in rock mass adjust once more so strongly after excavation resulted in stress relief because of deadweight and unloading that rock mass begin to subside and crack. The connection between the cracks and joints in formation rock mass of mountain body leads to mountain body cracking.Monitoring data analysis shows that construction plan are so reasonable that tunnel engineering structural is stably and secure.更多还原