Stability Analysis And Study On Slope And Dam Foundation With Jointed Rock Mass Of Luogu Hydropower Station

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...