【作者】 李建强；

【导师】 刘高；

【作者基本信息】 兰州大学 ， 地质工程， 2009， 硕士

【摘要】 基于地球系统科学和地质环境动态演化原理,依据大量现场实测资料,采用多种方法,分析了白鹤滩水电站坝址区玄武岩体内层内错动带的发育特征、结构性状和空间分布规律,探讨了LC成因机理和发育模式,研究了LC对坝址区岩体的影响和作用,为岩体力学研究和工程设计施工提供参考依据。论文主要研究了以下内容。(1)对现场地形地貌、水文地质条件和地层岩性等进行详细调研,坝区层内错动带发育特征受工程地质环境的影响。(2)通过对坝区61个勘探平硐、钻孔、场地测量、现场试验和测试等对LC及其他软弱结构面的精测,并应用结构面网络模拟技术分析LC的发育和岩体结构特征。结果表明坝区结构面左岸较右岸发育,倾向以SE组最为发育且迹长较长;LC具有明显的物质分带性,起伏度较大,整体近似平行。(3)依据LC发育特征和岩体结构性状的研究,应用地质学和岩石力学理论,分析LC的发育模式。坝区LC发育主要有平行、共轭、羽状和扫帚状四种。(4)据发育模式和区域工程地质环境及演化特征的研究,结合数值计算方法,探讨LC成因机理和发育过程。LC的发育主要受河流下切和构造运动作用的影响,河流不同下切阶段,对应LC的发育特征和发育模式也不相同。(5)运用结构面网络模拟技术,依据现场试验和测试数据,分析不同发育特征的LC对岩体力学性质的影响。研究表明岩体强度与LC的剪切夹角和间距成正比,与迹长成反比,且LC及LC附近岩体的变形模量和波速较小。(6)运用块体理论和赤平极射投影原理,分析坝区范围内块体组合模式,并根据刚体极限平衡理论对坝区斜坡、坝肩坡体和可能失稳块体进行评价。LC对岩体的作用主要表现为岩体稳定性的控制性作用,该坝区由LC及其它软弱结构面组成块体及坡体基本处于稳定状态。更多还原

【Abstract】 Based on the earth system science and dynamic evolution theory of the geological environment,the paper uses kinds of methods to analyze the development characteristics, spatial distribution and structure properties of intraformational faulted zones which locate in basalts,hydropower station of Baihetan,to explore the forming reasons and mechanism of LC, and to study the influence to rock mass in scope of the dam,according to lots of field measured data.The research result offers reference basis for study of rock mass mechanics and engineering design.The main contents are following.(1) The terrain landform,hydrology geology conditions and stratum lithology are investigated in detail,which shows that it has great influence of engineering geological environments to the develepment of intraformational faulted zones.(2) The paper tests the intraformational faulted zones and other weak structural planes by 61 prospect tunnels, drilling,surface measuring,filed experiments,and then uses discontinuity network simulation to analyze the development of LC and the rockmass structural characters.The ruesults suggest that the structural planes are grower on the left side than the right,and the most growest tendency is group SE and the trace is relative long.And it has obvious zoning on substances, lagerer undulation,approximate parallel in whole of LC.(3) Apply the theory of geology and rock mechanics,the paper analyzes the development pattern according to the study of development and structural characters of LC.There are four main patters as parallel, conjugate,plumose and broom shape by the results.(4) The numerical calculation is used to study the forming mechanism and development process according to the research of development patterns and regional geological environments of engineering and its evolution. The development of LC is mainly affected by river incision and tectonic movement.With different stadges,there are different development characters and patterns.(5) According to the data of field experiments and testing,using discontinuity network simulation,the paper analyzes what influence the different development characters have to rock mechanics properties.The rock mass strength is proportional to the shear angle and distence,inversely proportional to the length,and the deformation modulus and wave velocities are smaller of LC and their nearby rocks.更多还原