Fractured-rockmass Hydraulics Characteristics Under Atomization Condition&the Influence On The Deformation Of A Slope

Atomization is a strong storm rainfall by regulating flood of a hydropowerstation. Most of that rainfall intensity will achieve above the rainstorm intensity. Oncethe atomized flow infiltrated into the fractured-rockmass slope, that will cause seriousinfluence on the slope by the physical&mechanical effect of the infiltrated atomizedflow.With the construction of large scale&supersized hydroelectric project, in China,moreexcavated high side slope appeared. The deformation and stability of these slopeare under direct threat by the infiltrated atomized flow.In this thesis, after study of basic principles of fractured-rockmass hydraulics andsome existing research findings, the author have made a detailed analysis of the cubiclaw of a single fracture flow, and the basic mathematic model in fractured-rockmassseepage flow, and the saturated&unsaturated hydraulic parameters offractured-rockmass under infiltration. Then, use a stochastic simulation method calledMonte Carlo to generate the two-dimensional fractures network with the statisticsgeometric parameters of those fractures from a slope, which is located at the steep partof Pubugou hydropower station spillway exit. After that, the author analyse theequivalent continuum model&the equivalent requirements in detail. Building on theabove analyses, the author has determined the saturated conductivity tensor of thefractured-rockmass by the calculation. Also we can determine the unsaturatedhydraulic parameters of the fractured-rockmass by engineering analogy. Then theauthor makes an in-depth analysis of atomization factor from the mornitoring date ofthe atomization and deformation at this slope. On the base of theoretical, hydraulicparameters&mornitoring date analyses, we could choose a typical proile to analysethe doformation&percolation flow at this slope under atomization condition by FEM.So we can get some conclusion, from the result above, such as:1. As we know, fractured-rockmass is an inhomogeneous anisotropic medium.Groundwater percolation in this medium reflectes a high degree of anisotropy, thiscould be reflected by conductivity tensor more comprehensive. 2. In practical projects, the most important prerequisite is the existence and sizeof REV of using equivalent continuum model. Generally, if the length of the fracturesin the fractured-rockmass could reach the degree of10~20m, and the mean spacing ofa group fractures could be less than4m, the REV will always exist.3. In this thesis the author use a comprehensive approach which isfractures-geometric statistics&engineering analogy, to determine the saturated andunsaturated hydraulic parameters. Then we could recognize the hydraulic parametersthat determined by this approach is correct for the practical project, also we could getthe reliable calculation. And this approach is provided with a convenient feature, thecalculation could give some guidance for the safe operation of the project.4. Because of the lower position of the groundwater table, it shows little or nochange under every atomization condition, by analyse the calculation of thisfractured-rockmass slope seepage. However, some transient saturated zonematerializes in the shallow slope. Furthermore, In addition to the atomizedinfiltrantion volume&duration time, the transient saturated zone also has closerelation to the slope structure.We find that the transient saturated zone is formed moreeasily, when there’s a strong permeability accumulation layers above the fracturedrockmass, or nearby the diabased-dike. Once the atomized infiltrantion stop, thetransient saturated zone in that two areas dispered in a short time, but the transientsaturated zone in low permeability fracturedrockmass, such as Ⅳ~Ⅴ fracturedrockmass, dispered need more time.5. On the base of analysis of atomized infiltration, here we use FEM to calculatethe deformation of this slope by single coupled PWP. It’s not hard to see thedeformation of this slope ralate to the transient saturated zone closely. TheX-displacement maximum value of this slope also appeare in the lower part, nearbythe diabased-dike. The maximum value always reach the degree:2.3~2.5cm, sosuggesting that this part should be enhanced monitored.