【作者】 蒙覃军；

【导师】 徐卫亚；

【作者基本信息】 河海大学 ， 防灾减灾工程及防护工程， 2007， 硕士

【摘要】 实际工程中，边坡和坝基中的岩体常被节理、裂隙、断层等结构面所切割，构造十分复杂。由于节理岩体的存在，将减小岩体的强度，增加岩体的变形，致使岩体的强度和变形表现为不均匀性和各向异性，岩体的工程力学性质受到严重影响。边坡与坝基的稳定直接影响到大坝的安全，因此受节理岩体影响的边坡与坝基稳定性研究显得极其重要。 洛古水电站拟建为碾压混凝土重力坝。坝址区右岸存在F107断层，且右坝肩缓倾角结构面发育，以岩屑夹泥型为主，其作为底滑面易与F107断层组合，对右坝肩抗滑稳定不利，对边坡稳定不利。研究表明，F107断层与缓倾角结构面对边坡与坝基稳定的影响明显。坝基的开挖存在两套方案，本文旨在研究两套方案中节理岩体边坡与坝基的稳定性，通过比较分析，提出较优方案，并对较优方案进行地震动力响应分析。本文的主要研究成果如下： （1） 论述有限差分法的基本原理与计算方法，建立了两种方案下右岸坝肩边坡开挖后的平面模型，采用有限差分法软件FLAC^3D进行了两种方案受节理岩体影响的右岸坝肩边坡开挖加固前后的水平位移分析；分别建立两种方案典型坝段平面模型，模拟了坝基中的J2、J3、J4缓倾角节理和F107断层，进行两种方案典型坝段的应力位移分析；分别建立两种方案典型坝段和坝基、边坡共同作用下的三维模型，进行了常规计算，分析了总体应力变形规律。 （2） 采用强度折减法对坝肩边坡开挖加固前后和整个坝体坝基进行了分析研究，分析了受节理岩体影响的坝肩边坡滑块稳定性和坝基岩体抗滑稳定性，得到边坡和坝基的稳定安全系数；基于强度折减法，对坝基岩体进行了节理参数敏感性分析，提出不同节理参数取值下的稳定安全系数。 （3） 采用基于Dijkstra算法的极限平衡有限元法研究两种方案受节理岩体影响的右岸坝肩边坡岩体开挖后的稳定性以及可能产生的滑动模式和机理，得到边坡的稳定安全系数。 （4） 通过以上的计算结果，分析比较两套坝基开挖方案，认为第二套方案较优；对第二套坝基开挖方案进行地震动力分析研究，采用振型分解反应谱法，分析研究了典型坝段和整体三维模型在地震作用下的应力位移状态。 本文的研究基于洛古水电站工程，有明确的工程实践背景，紧密结合实际工程。本文所取得的研究成果，为洛古水电站工程的设计与施工提供了重要的参考价值，对其它类似工程具有较大的指导意义。部分成果已应用到洛古水电站坝肩边坡的施工中。更多还原

【Abstract】 In actual project, the rock mass in dam foundation and slope often is cut by structural planes such as joints, cracks, faults, its structure is very complicated. The existed jointing rock mass will diminish the intensity, increase deformation, cause the intensity and deformation of rock mass showing for inhomogeneity and anisotropism, and badly affect the engineering mechanics character of rock mass. The slope and dam foundation stability have direct impact to the safety of dam. So it is very important to study the stability of slope and dam foundation affected by jointed rock mass.The Luogu hydropower station is designed as roller compaction concrete gravity dam. The F107 fault is existed in the right bank of dam site.The low angle structural planes are developed in the right dam shoulder, containing mostly rock fragments and little mud.They are easy to be the bottom of sliding surface ,assembling with F107 to be a block.The block is harmful to right dam shoulder and slope.The research show that, the F107 fault and low angle structural planes obviously affect the stability of slope and dam foundation.There are two schemes in dam foundation excavation.The purpose of this paper study the stability of slope and dam foundation with jointed rock mass in two project, compare and bring forward better scheme, and dynamic research is done for it.The main works of this paper are as follows:（1） The basic principles and calculation methods of finite difference method are discussed.The finite difference model is built for right dam shoulder slope excavated in two projects. The finite difference software, named as FLAC^3D, is adopted to analyse the horizontal displacement of right dam shoulder slope excavated and reinforced in two projects, which is affected by jointed rock mass. The plane models of typical monolith in two projects are built to analyse the stress and displacement. The model simulate J2,J3,J4 low angle joint and F107 fault in the foundation.The stability of foundation rock mass is studied. 3D model of typical monolith, foundation and slope in two projects are built to do routine calculation, then analyse the whole stress deformation law.（2） Strength reduction method is adopted to study dam shoulder slope excavated and reinforced, and study the whole dam body and foundation.The stability of slipe of dam shoulder slope and foundation rock affected by jointed rock mass is analysed. The stability safety factor of the slope and foundation is worked out. Sensitivity analysis, base on strength reduction method, also be adopted .At the same time, the safety factor in different joint parameter is worked out.（3） Limit equilibrium finite element method based on Dijkstra arithmetic is adopted to study the stability and the possible sliding pattern and mechanism of right excavated dam shoulder slope affected by jointed rock mass in two projects, and stability safety factor of the slope is worked out.（4） By the above result, two projects is analysed and compared. It is considered that, the second one is better Dynamic research is done for the second project in earthquake. Mode-superposition response spectrum method is adopted to study stress更多还原