| Over the vast areas surrounding Qinghai-Tibet Plateau of China, deep valley develops, theslope of topography is steep, Complex regional geological tectonic develops and theearthquake is frequent; High and steep slope and Engineering Slope are the main area whichgenerate Large geological disasters and massive damage of Engineering Slope, On the regionswhere sedimentary rocks or layered rocks are widely distributed, especially, problems ofdamage of bank slope toppling rockmass and disaster’s inoculation、formation are moreserious. A large amount of research achievements are obtained in recent years in both Chinaand abroad, but most objects are paralelel valley bank slope toppling rockmass. In thisarticle, the research of object, named the right rank of damsite of Lancang River Wunonglonghydropower station(Qd1), which belongs to transverse valley bank slope toppling rockmass,locates over the right bank of damsite. The toppling rockmass is a threat to project safeconstruction and normal operation, and the research of its stability will be important toEngineering practice. A systematic study is carried out in this article in many aspects on theapplication and innovation of geological exploration technology of toppling rockmass、initialstructure of rock slope、the spce-time characteristics and causes of toppling rockmass、mechanics characteristic and the safety evaluation of toppling rockmass:(1) Distribution characteristics and range of toppling rockmass is obtained by differentprecision of the geological mapping in prevent of ignoring in normal mapping because thetoppling rockmass is developed on transvers valley and distributed outside of the expectedexcavation areas; and integrated exploration of drill and tunnels is arranged on the basis of itso as to determing the scope of the toppling rockmass in three-dimensional form.(2) Undisturbed sampling method and technique which is suitable for making topplingrockmass into block and massive debris is achieved through SM plant gum Wall drillingtechnology and experimental adjustment of drilling factors and SM plant ration; Problemsof the processing、fix、transport of the rock sample of toppling rockmass is resolved throughthe new method—-"Shrink seal fixed technology" and undisturbed samples are mainly gained;A large amount of Mechanics experimental data is gained through the mechanics test on theadvanced MTS testing machine.(3) According to the rock structure theory an classification of index of Zhende Gu, accuratelayer measurement and survey method are adopted; On the basis of very accurate data, rockdivision is first carried and then rock structure division is taken for the characteristics of thisset of lithology and rockmass structure; Then, result that the structure of the rock of topplingrockmass is Thin Interbeds, slope structure is transverse slope and it has characteristics ofparallel bedding structure if the topographic slope in the direction of the tendency of the rockis considered;(4) According to a large amount of data of the position、aperture of structure planes of toppling rockmass which is disclosed by the main tunnels on the right dam abutment, trackingfeature of pull fission shape of the toppling rockmass to the structure of surface is analysed.On basis of a large amount of statistical data and related data, the direction、degree、type、depth of the deformation and the boundary conditions of toppling rockmass is studied.(5) Deformation mechanism of toppling rockmass is comprehensively analysed through manyaspects on Topography condition, structural characteristics of rock mass, lithology changerule, fracture development situation, valley stress field and so on; toppling deformation of thetilted high slope is studied by numerical analysis method.(6) On the basis of the analysis of the duration and formation mechanism of topplingrockmass and the deformation characteristics of Wunonglong toppling rockmass, newmethods of analying displacement value of toppling rockmass by using the displacementbetween original shape strata and toppled strata "particles" of toppling rockmass andpreliminarily getting flow rate of toppling rockmass by using geologic age are put forward;Through the inversion of program of FLAC3D, the displacement of toppling deformation is inaccordance with strata particle displacement analysis. The application of strata particledisplacement analysis is supplement for the method of rheological parameters of rock massselection.(7) We utilize limit equilibrium method, the finite element method, the coefficient of theintensity of reduction to compute and analyse the toppling rockmass by selectingrepresentative profiles and the reasonable strength parameters, and we get very encouragingresults especially using the coefficient of the intensity of reduction. We also make sensitivityanalysis for toppling rockmass, so as to the reasonable management plan according to eachfactor’s sensitive degree later. On the basis of computation and analysis, we put forward ourengineering treatment suggestion. |
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