金沙水电站坝后高位滑坡变形历史及成因分析OA

In recent years,repeated deformations have occurred on the high-elevation slope on the right bank of the Jinsha Hy-dropower Station in the Jinsha River,threatening the safety of the downstream dam.Focusing on the Shanliangzi Landslide,a high-elevation failure associated with a behind-dam abandoned mining area at the Jinsha Hydropower Station,this study systemati-cally investigated the time-series deformation curves and historical failure processes before and after landslide mitigation.Multi-ple technical approaches were integrated,including field reconnaissance,unmanned aerial vehicle(UAV)photogrammetry,visual interpretation of optical remote sensing satellite imagery,and time-series InSAR analysis based on Sentinel-1A ascending orbit data.The key findings were as follows:①Field investigations revealed that the 2018 landslide was primarily triggered by two fac-tors:roof collapse of the underlying abandoned mining area and rainfall infiltration.② Comprehensive analysis indicated that the tensile stress zone induced by mining-induced roof caving propagated from the slope surface upward to the crest,resulting in ten-sile cracking and subsidence at the landslide's rear edge.Primarily influenced by self-weight,the rock-soil mass exhibited a tendency to move downward toward the free face.Gradual expansion and interconnection of the lower cracks and rear-edge ten-sile cracked eventually formed a continuous sliding surface.The failure mode of the Shanliangzi Landslide was classified as a"col-lapse-tensile cracking"retrogressive type.③ Field surveys in 2024 identified newly developed cracks at the landslide's front edge.InSAR interpretation results further confirmed that the slope,despite mitigation measures,remained influenced by the aban-doned mining area and exhibited ongoing creep deformation characteristics.This study provides references for ensuring the long-term safe operation of the Jinsha Hydropower Station.