Development Principle Of Landslide And Stability Risk Analysis Of Slop Of Reservior Bank Of Boluo Hydroelectric Power Station In Jinsha River

An investment in Boluo Hydroelectric power station is a large-scale project in Jinsha River ,which is located in the main stream of the junction between the Autonomous Region Jiang Da County of the Tibet and the Bai Yu County of the Sichuan Province. The power station will be programming normal water level elevation of 2989m, using drop 100m, installed capacity of 960000Kw. After the water storage, the slope stability of the hydropower project will be the main issue of Engineering Geology .The stability evaluation and prediction of the reservoir banks is major issues on the construction of hydropower projects, which has important practical significance in the election of the dam site area, the governance of regional instability.By the study of information on regional geological collected by Predecessors ,the author adopts the combining method of field research and indoor Analysis to analyze the regional geological context ,the geological conditions of the reservoir area and the geological structure bank slope based on the identification of the geomorphologic features, the stratigraphic lithology and the geological structure of the reservoir area, focus on the deformation-damage mode and the regulation of the bank slope , adopt the field qualitative geology evaluation, the integrated evaluation of the factors and the evaluation of the fuzzy mathematics to estimate the extent of risk of the bank slope and calculate the probability of each section of bank slope in the paper and educe the destruction probability of bank slope of the reservoir.Firstly, the geological conditions are very complex , which are mainly high canyon landscapes, most of which are "V"-Canyon and some other parts of the river are open valleys and the slope gradient is more than 40 degrees (angles).The rock lithology includes phyllite , gneiss and marble and the rock mass surfers serious weathering. geological structure of Reservoir is intricated and develops a number of faults and folds.Secondly, By the study of the regional geological setting, the geological background of the surveyed region and the structure of soil and rock mass of the bank slope, which shows that the Valley geological structure of the reservoir area mainly includes Vertical slope valley slopes, oblique valley slopes and horizontal Valley slopes and the deformation and damage mechanisms of the bank slope is more bend-fracturing-oriented, flat slip-fracturing and wedge-slip -fracturing less.Thirdly, landslide majorly is developed by the Ptxna gneiss of the yuan-old community-group gneiss group gneiss and the T₃l phyllite of the Triassic-Talana rock group but the other strata less. Landslides mainly distributed in the vertical Valley and the Oblique Valley (such as the Boluo rural- Yusong rural, the Dong qianlong-Jinsha rural, the Jinsha rural - Baiyu County), the horizontal Valley less so landslide forms in the narrowness valley but in the vast valley.Lastly, the author adopts the method of qualitative geology evaluation, the integrated evaluation of the factors and the evaluation of the fuzzy mathematics to estimate the extent of risk of the bank slope and calculate the probability of each section of bank slope in the paper, which indicates that the general stability of the banks is good, the percentage of stable bank is 66.7%, the percentage of basically stable bank is 26.7% and the percentage of unstable bank is 0.5% .The stability of cross valley and the middle dip angle -parallel valley is good, and the bank slopes of poor stability mainly distribute in the high dip angle -parallel valley and the high dip angle-insequent valley.