现代地质2024，Vol.38Issue(2)：451-463,13.DOI:10.19657/j.geoscience.1000-8527.2023.090
金沙江上游沙丁麦大型古滑坡发育特征与稳定性评价
Development Characteristics and Stability Evaluation of the Shadingmai Large-scale Ancient Landslide in the Upper Reaches of Jinsha River,Tibetan Plateau
摘要
Abstract
The Shadingmai ancient landslide is located in the upper reaches of the Jinsha River.The Degong-Shedan Fault from the Jinsha River Fault system passes through the front part of the landslide,causing a large scale of rock fractures.Combined with the effects of regional rainfall and human activities,the landslide experi-ences an intense deformation,posing a risk of unstable sliding.This causes a serious threat to the lives,proper-ties of residents,and critical transportation in the upstream region of the Jinsha River.To investigate the key is-sues such as the developmental characteristics and stability of the Shadingmai ancient landslide,this study con-ducted remote sensing interpretations,InSAR deformation monitoring,rainfall analysis,and numerical simula-tion of landslide stability for the landslide.The study investigated the current deformation characteristics of the landslide and explored its stability under different conditions.The research results indicate that the Shadingmai ancient landslide is approximately 2,100 m long and 1,300 m wide,with a thickness of approximately 15-20 m.Its volume ranges from 2,180 x 104 to 2,900 x 104 m3,making it a super-large accumulation landslide.In terms of its spatial distribution,it can be divided into three regions,as the ancient landslide rear edge region(Ⅰ),the ancient landslide accumulation region(Ⅱ),and the strong deformation region(Ⅲ),which further includes two reactivated deformation zones(Ⅲ1 and Ⅲ 2).The main deformation phenomena of the landslide in-cluded tensional cracks,building fissures,steep displacement faults,and localized collapses.Based on SBAS-InSAR monitoring results,the maximum surface deformation rate reaches to-51.88 mm/a.Combined with the regional rainfall data,the cumulative deformation of the landslide exhibits a'step'growth pattern.Heavy rain-fall is one of the significant factors influencing the deformation of the landslide mass.The stability calculation of the landslide using FLAC3D shows that the deformation mode is characterized by retrogressive deformation.Under natural conditions,the landslide is in a relatively stable state with minimal slope deformation.However,under extreme heavy rainfall conditions,the landslide becomes unstable,exhibiting tension and shear failures,with the sliding surface penetrating and causing overall instability and significant hazards.关键词
金沙江上游/沙丁麦/古滑坡/变形监测/数值模拟Key words
upper reaches of the Jinsha River/Shadingmai/ancient landslide/deformation monitoring/nu-merical simulation分类
天文与地球科学引用本文复制引用
邱振东,郭长宝,吴瑞安,简文星,倪嘉伟,张亚楠,闫怡秋..金沙江上游沙丁麦大型古滑坡发育特征与稳定性评价[J].现代地质,2024,38(2):451-463,13.基金项目
国家自然科学基金青年科学基金项目(42207233) （42207233）
中国地质调查局地质调查项目(DD20190319,DD20221816). （DD20190319,DD20221816）
