摘要
青藏高原日益频发的冰岩崩灾害对人类生命、重大工程等构成严重威胁。为深入揭示冰岩崩成因机理、填补地质力学模式分类空白,采用工程地质和地质力学方法分析得出,青藏高原冰岩崩是特殊地理、地质和气候环境下斜坡变形破坏的产物。高陡地形和多元结构为冰岩崩的形成提供了临空和边界条件;地震促使冰岩体进一步开裂破碎;气候变暖导致冰雪融水沿裂隙与边界渗流,显著降低滑动面(带)强度,甚至形成短时高压水头,进而触发冰岩崩。“解约束”是决定冰岩崩的临界点,主要表现为冰岩失稳区与侧壁、底部基床及母冰川黏结的瞬时或渐进失效。青藏高原冰岩崩分为4类:蠕滑−拉裂型(细分为加载压融−水致蠕滑−拉裂、气象生水−水致蠕滑−拉裂)、蠕滑−倾倒型、楔块滑移型和坍塌型(细分为空穴坍塌、侵蚀坍塌)。这些模式在同一冰川流域内可以共同发育、相互耦合、链生成灾。该研究对于科学认识冰冻圈灾害,指导青藏高原防灾减灾具有理论和现实意义。
[Objective]The increasingly frequent ice and rock avalanche hazards on the Tibetan Plateau pose a serious threat to human life and major projects.[Methods]To further reveal the mechanisms of ice and rock avalanches and fill the gap in the classification of geological mechanics patterns,engineering geological and geomechanical methods were applied to derive the following.[Results]The ice and rock avalanches on the Tibetan Plateau result from slope deformation and failure under special geographical,geological,and climatic conditions.The steep terrain and diverse structure provide the spatial and boundary conditions for the formation of ice and rock avalanches.Earthquakes promote further cracking and fragmentation of the ice and rock masses.Climate warming leads to the infiltration of meltwater along the crevasses and boundaries,which significantly reduces the strength of the sliding surface(band),and can even form a short-term high-pressure water head,triggering the ice and rock avalanches.The"discontinuity"serves as a critical threshold for ice and rock avalanches,primarily manifested through instantaneous or progressive failure in the bonding between instability zones,lateral walls,base beds,and parent glaciers.[Conclusion]Ice and rock avalanches on the Tibetan Plateau can be categorized into four geological mechanics patterns:the creep-fracture type(subdivided into"loading-induced pressure melting-water-induced creep-fracture"and"weathering-induced water-induced creep-fracture"),the creep-toppling type,the wedge slip type,and the collapse type(subdivided into"cave collapse"and"erosion collapse").These patterns may coexist,interact,and chain-react within the same glacial basin.[Significance]This study holds both theoretical and practical significance for advancing the scientific understanding of cryospheric hazards and supporting disaster prevention and mitigation efforts on the Tibetan Plateau.
作者
汤明高
赵欢乐
许强
李广
冉旭
喻永恒
钟益华
郭道静
朱星
TANG Minggao;ZHAO Huanle;XU Qiang;LI Guang;RAN Xu;YU Yongheng;ZHONG Yihua;GUO Daojing;ZHU Xing(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,Sichuan,China;College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059,Sichuan,China;Institute for Disaster Management and Reconstruction,Sichuan University,Chengdu 610200,Sichuan,China)
出处
《地质力学学报》
北大核心
2025年第5期940-959,共20页
Journal of Geomechanics
基金
国家自然科学基金项目(42377199,41941019)。
关键词
青藏高原
冰岩崩
气候变化
地震
成因机理
地质力学模式
Tibetan Plateau
ice and rock avalanche
climate change
earthquake
genetic mechanism
geological mechanics patterns
