高位远程地质灾害研究:回顾与展望

Research on high-altitude and long-runout rockslides:Review and prospects

在全球范围内,高位远程地质灾害造成了多起群死群伤事件和特大经济损失,是特大型地质灾害防灾减灾科技攻关的难点。文章系统回顾了高位远程地质灾害的研究历程,认为常规的“高速远程滑坡”研究难以适应高山、极高山区复合型地质灾害防灾减灾的要求,提出了从高位失稳、远程成灾和风险防控全链条的高位远程地质灾害研究思路,探讨了高位崩滑启动源区的易灾地质结构特征和早期识别技术、高速碎屑流远程链动机理和边界层效应以及风险评估和防灾减灾问题。通过对青藏高原高山、极高山区的高位远程地质灾害研究,揭示了高位滑坡碎屑流势流体链动传递机理,以及紊流体和犁切体的边界层效应,提出可以通过改造高势能碎屑流体的边界层底坡、增大湍流边界层内湍动能的生成与组合障桩前死区范围的消能降险方法。最后,针对铁路、公路、水电工程、边疆城镇和国防建设的发展,讨论了复合型高位远程滑坡灾害的防灾减灾将面临的新挑战,提出了易灾地质结构孕灾机理、高位远程链灾动力过程和风险防控理论与技术等3方面亟待加强的研究方向。

Long-runout rockslides at high altitude have caused lots of severe casualties and huge economic losses in the world,becoming a focus issue in researches on mitigation for large-scale geological disasters.This paper systematically reviews the research process of high-altitude and long-runout rockslides and believes that conventional research on“high velocity and long runout”is difficult to adapt to the requirements of complex geohazards prevention and mitigation in high and extra-high mountains.The methodology on high-altitude and long-runout rockslides has been proposed that includes in the initiation at the high-position,the dynamics of chain-style disasters with a long-runout traveling and the risk assessment and mitigation.Then,the disaster-prone geostructure characteristics and early identification techniques of the high-altitude initiation zone,the longrunout transferring mechanism and boundary layer effect of high-velocity debris avalanche,and risk assessment and mitigation issues have been explored.Through the study in the high mountain and extra-high mountains of the Qinghai-Tibet Plateau indicates that the potential flow transferring mechanism of debris avalanche in high-altitude rockslides,the boundary layer effect of turbulent fluid and the plowing bodies.It is proposed that energy dissipation and risk mitigation methods can be used by modifying the boundary layer bottom slope of high potential debris avalanche,to increase the generation of turbulent kinetic energy in the boundary layer,and the dead zone range in front of barrier piles.Three research directions have been discussed,including the initiating mechanism of disaster-prone geostructure,the dynamic process of high-altitude and long-runout disaster chains,and the theory and technology of risk prevention and mitigation.