Stability Analysis And River Blocking Prediction Of The Lajinshengu Landslide Of The Upstream On Lancang River

Landslide is one of the common geological disasters,especially in Southwest China.We must strengthen the research of landslide stability analysis method to reduce the threat of landslide disaster.This article takes the Lajinshengu landslide on the right bank of the Lancang River in Yanmen Township,Deqin County,Yunnan Province as the research object,and briefly introduces the regional geological conditions of Deqin County.In this paper,comprehensively evaluate the Lajinshengu landslide through numerical simulation,and predicts the height of the dammed dam based on the landslide stability evaluation results.The main research contents and results of this paper are as follows:(1)Based on the data of Lajinshengu landslide,the basic structure and genetic mechanism of Lajinshengu landslide are analyzed;the landslide body is mainly composed of gravel soil with a volume of about 1815×10⁴ m³,It is a very large deep landslide.Reservoir impounding is the main inducing factor.(2)Use SLOPE/W to analyze the stability of Lajinshengu landslide under different working conditions.The results show that:Under natural conditions,as the reservoir water storage landslide stability decreases by 3.00%,the landslide is basically stable after the water storage;Under rainstorm and earthquake conditions,landslide is in an unstable state,and its stability is lower under earthquake conditions,which is a more unfavorable factor.(3)The finite element software FLAC^3D is used to perform numerical simulation calculations on Lajinshengu landslide under different working conditions.The results show that under different working conditions,the largest displacement of the landslide is at the shear outlet of the landslide front.The water storage of the reservoir mainly affects the displacement of the front edge of the landslide,and the total displacement of the front edge after the water storage is increased by 34.2%compared with that before the water storage;The total displacement of post-water rainstorm and earthquake conditions is 3?4 times that of natural conditions;the shear strain increment and shear plastic zone distribution of landslides are basically the same,and they are all distributed on the potential sliding surface.(4)Based on the calculation results of the lajinshengu landslide,The discrete element software 3DEC numerical simulation method and slip distance estimation algorithm are used to predict the height of the landslide blocking the river.The results show that:the predicted height of blocking river obtained by 3DEC numerical simulation method is 65?75m,and the predicted height of sliding distance calculation method is 67.89m,the difference is not big,which indicates that the prediction of blocking river height based on 3DEC numerical simulation method has certain feasibility and reliability,and can be used to guide the prediction calculation of landslide blocking river.