Evaluation Of Slope Stability In Northeastern Margin Of Tibetan Plateau Based On Scoops3D Model

As the main type of geological disasters in the northeastern margin of the Tibetan Plateau,landslides have caused huge casualties and economic losses.Therefore,it is of great significance to find out the stability of the slopes in this area.The use of physical deterministic models for landslide stability analysis has become a hot spot in landslide hazard research at home and abroad.Many models do not consider the three-dimensional properties of the stratum and cannot reflect the terrain fluctuations,thereby affecting the accuracy of the simulation results.The Scoops3 D model will induce three-dimensional landslides.Terrain elements are taken into account,improving the accuracy of the simulation.Therefore,this paper selects Jiajiagou on the northeastern margin of the Tibetan Plateau as the study area,and simulates and predicts the spatial location of landslides based on the Scoops3 D model.Firstly,remote sensing images are used to visually interpret the landslides in the study area,and at the same time,the landslides are catalogued in combination with field investigations;then,the geotechnical samples in the study area are collected through field investigations,and the geotechnical parameters are obtained through indoor direct shear experiments.By inputting three digital elevation models(DEMs)with different resolutions and two search ranges for landslide areas,the model results were compared with landslide points,and the parameter combination with the best simulation effect was obtained.Finally,the variation law of landslide stability under different ground motion accelerations is analyzed,and the conclusions are as follows:(1)The unstable areas simulated by the Scoops3 D model are concentrated on both sides of the valley,and the simulation accuracy exceeds 70%,indicating that the model has good applicability for the identification of regional landslide stability.The DEM resolution and the landslide area search range are related to each other and affect each other,which will have an impact on the model results.The model obtained the best simulation results under the combination of 5 m resolution and 1×10~3-1×10~4 m~2 parameters.(2)From the identification results of DEMs with three different resolutions,the higher the DEM resolution,the higher the ability of the model to correctly identify landslides.However,the non-landslide areas are easily identified as landslide areas due to the complexity of the ground object information expressed by the high-resolution DEM data.(3)Under the same DEM resolution,different landslide area search ranges have different influences on the model results.In the case of high-resolution DEM,the landslide area search range has less influence on the model,while for low-resolution DEM.This difference becomes larger as the DEM resolution becomes lower,and for low-resolution DEMs,a larger landslide area search range can obtain a better simulation result.(4)By simulating the regional landslide stability distribution law under six different ground motion acceleration coefficients,it is found that with the increase of ground motion acceleration,the regional stability decreases rapidly.The greater the slope,the larger the effective face of the slope,the easier it is to reduce the stability under the action of earthquakes and cause landslides.