青藏高原东部活动构造带大型滑坡成灾背景与灾变机制  

Large Landslides along Active Tectonic Zones of Eastern Tibetan Plateau: Background and Mechanism of Landslide Formation

作　　者：郭长宝[1,2,3] 吴瑞安 钟宁[1,2,3] 杨志华 袁浩 李彩虹[1] 邱振东 曹世超 Guo Changbao;Wu Rui'an;Zhong Ning;Yang Zhihua;Yuan Hao;Li Caihong;Qiu Zhendong;Cao Shichao(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Active Tectonics and Geological Safety,Ministry of Natural Resources,Beijing 100081,China;Research Center of Neotectonism and Crustal Stability,China Geological Survey,Beijing 100081,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部活动构造与地质安全重点实验室,北京100081 [3]中国地质调查局新构造与地壳稳定性研究中心,北京100081

出　　处：《地球科学》2024年第12期4635-4658,共24页Earth Science

基　　金：中国地质调查局项目(No.DD20221816);国家自然科学基金项目(No.42372339)。

摘　　要：活动构造带内大型特大型滑坡成灾机理复杂、危害严重,以往关于其发育特征、成灾背景与灾变机理等研究主要侧重于降雨、地层岩性、地震等因素分析,关于其内动力控灾背景和机理研究一直是学术界和工程界的难题.基于遥感解译、资料收集、野外调查和典型案例剖析,建立了青藏高原东部川藏交通廊道地质灾害数据库,提出了一种考虑地形起伏度的区域地壳稳定性评价方法,研究表明约62%的地质灾害发育于地壳不稳定区和较不稳定区内,内动力地质条件对地质灾害的时空分布具有极大影响.大型滑坡的发育分布受活动构造带控制显著,主要表现为复杂地质构造孕育大型滑坡、特殊岩土结构控制大型滑坡、强烈地震活动诱发大型滑坡、断裂持续蠕滑促进大型滑坡灾变等4类特征,具有显著的活动构造带孕灾-控灾-诱灾-促灾等复杂灾变演化过程.研究结果对于促进青藏高原大型特大型滑坡灾害的成因机理,提升特大滑坡灾害风险防范研究具有重要指导意义.Large and extremely large landslides along the active tectonic zones are complex and hazardous.Previous researches on these landslides development characteristics,disaster backgrounds,and formation mechanisms have primarily focused on factors such as rainfall,stratigraphic lithology,and seismic activity.However,studies on the endogenic dynamic control of disaster backgrounds and formation mechanisms have remained challenging for both the academic and engineering communities.Based on remote sensing interpretation,data collection,field investigations,and analysis of typical landslide cases,this study established a geological hazard database for the eastern Tibetan Plateau along the Sichuan-Xizang transportation corridor and proposes a regional crustal stability assessment method that considers terrain relief.The study reveals that about 62%of geological hazards occur in the unstable crustal areas and relatively unstable crustal areas,where endogenous geological conditions significantly influence the spatial and temporal distribution of geological hazards.The development and distribution of large landslides are significantly controlled by active tectonic zones,displaying four characteristics:complex geological structures fostering large landslides,specific geotechnical structures controlling large landslides,strong seismic activities inducing large landslides,and continuous fault creep promoting catastrophic landslides.These characteristics contribute to a complex disaster evolution process that includes disaster fostering,control,induction,and promotion within active tectonic zones.The research findings are vitally important for understanding the formation mechanisms of large and extremely large landslides on the Tibetan Plateau and enhancing research on risk prevention for these landslides.

关 键 词：青藏高原 大型滑坡 活动构造带 区域地壳稳定性 内动力地质条件 工程地质 

分 类 号：P694[天文地球—地质学] P642