The Stability Studies And Calculation Of Landslide-triggered Waves Of Temi Landslide Of Batang Hydropower Station In Jinsha River

The Temi landslide is located in the left bank of Jinsha River, about 3700 m upper from the Batang Hydropower Station midstream damsite. The relative difference of height is about 700 m and it is a huge ancient rock landslide. The safety problem arises with the development of hydropower station because of the place where Temi landslide located. The rock mainly exposed in study area is P1 c rock consists of grey quartz sericite schist, calcite schist, bedded structure marble and quaternary deposit. Forecast and analysis the stability of Temi landslide under different adverse condition is meaningful and important.This paper studies mainly about the stability of Temi landslide under the condition of earthquake, heavy rain and reservoir impoundment, analysis the formation mechanism and the influence of landslide-triggered waves. The studies based on field geological survey, Borehole geological exploration, laboratory experiments, numerical simulation and analogy analysis. The geological exploration work elaborated the geological environments of study area, the scale and deformation behavior of the landslide. The 3-D stability analysis is based on the method of fast lagrangian analysis; the saturated–unsaturated seep analysis is build on the 2-D finite element method. At the last of the paper, the influence of landslide-triggered waves is forecasted by use different method. The main conclusions and results are as follows:(1)Based on the feature of the landslide and the geological environments, the formation mechanism and developing process of the landslide is analyzed. The developing process of the landslide can be divided into 4 parts: The back of the landslide became cracked. ? The bulging appeared in the middle of the landslide. ?The slipping plane is formed and the soil slided as a whole and blocking the river. ?Twice dam breaking and then formed the landslide shape.(2)The numerical simulation of the landslide under earthquake is dealt with the software Flac3 D because of its powerful ability on non-linear dynamic analysis. The result shows that Temi landslide is still stable under earthquake which seismic acceleration is 0.18 g and Seismic period is 0.41s(3)The numerical simulation of the landslide which under the conditions of landslide under heavy rain and reservoir impoundment is analyzed by use the software Flac3 D and Geostudio. The result shows that the landslide remains stable under heavy rain condition and will be at Limit stable state when the reservoir water level rise up to 2545 m and at broken state when the reservoir water level rise up to 2550 m,which the damage probability is about 78%.(4)The forecast of landslide-triggered waves is made according to the condition which reservoir water level rise up to 2550 m. Damage range and slip velocity is calculated, thus the height of the waves arrived at damsite can be doped out.