摘要
三峡库区巫山县靴子岩W2危岩属于基座损伤型危岩.受自重、风化卸荷及岩溶等因素影响,危岩基座压裂损伤明显,形成了不断劣化的凹岩腔,一旦失稳崩塌形成涌浪,将影响通航船只和临近码头安全.为研究这类基座损伤型危岩的起动机理,本文依据精细化勘察成果建立了该危岩的力学模型,采用离散元UDEC模拟了W2危岩崩塌的破坏过程,并利用基于概率分析的RocPro3D模拟了崩塌的运动过程及轨迹.研究结果表明:基座损伤型崩塌主要经历两阶段的复合式破坏.初期破坏模式为“沉降-鼓胀”,后续为“滑移-倾倒”;基座中部的鼓胀变形导致基座不均匀沉降,造成危岩后倾到,缓外倾的底滑面形态造成危岩向前倾到;W2危岩潜在崩塌轨迹覆盖整个下部河道,入河瞬间的最大能量达193100 kJ,最高速度达70.56 m/s.本研究可为基座损伤型崩塌力学机理的分析提供新方法,对三峡库区崩塌防灾减灾具有一定的指导意义.
The W2 perilous rock of the Xueziyan in Wushan County within the Three Gorges Reservoir area,is affected by factors such as self-weight,weathering unloading,and karst processes.The foundation displays evident fractures and damage,resulting in continuously deteriorating concave rock formations,which is classified as a pedestal-damage perilous rock.In the event of instability and collapse,the rock mass will generate surging waves,posing a threat to navigation and adjacent docks.This paper aims to investigate the initiation and dynamic mechanisms of pedestal-damaged perilous rocks.It establishes a mechanical model based on detailed survey results for rock masses with weak foundations.The failure process of the perilous rock W2 is simulated by the UDEC in Discrete Element Method(DEM).Additionally,the collapse process and collapse trajectory are simulated using probabilistic analysis software RocPro3D.The findings reveal that:the collapse of pedestal-damaged perilous rock primarily experiences two stages of compound failure.The initial deformation involves“Settling-Swelling”followed by“Sliding-Tipping”.Swelling deformation in the foundation's central region leads to uneven settlement,causing backward tilt of W2.Moreover,the gently outward-slanting basal sliding surface causes forward tilt of W2.The potential collapse trajectory of the perilous rock W2 spans the entire lower river channel,with the maximum energy upon river entry reaching 193,100 kJ and the peak velocity of 70.56 m/s.The study introduces a novel approach for analyzing the mechanical mechanisms of collapses in pedestal-damaged perilous rock,providing valuable guidance for preventing and mitigating collapses in the Three Gorges Reservoir area.
作者
吴茂林
罗刚
梅雪峰
周鹏
WU Maolin;LUO Gang;MEI Xuefeng;ZHOU Peng(Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,China;Shandong University of Technology,Zibo 255000,China;Chongqing Institute of Geology and Mineral Resources,Chongqing 401120,China)
出处
《三峡大学学报（自然科学版）》
CAS
北大核心
2024年第4期44-51,共8页
Journal of China Three Gorges University：Natural Sciences
基金
国家重点研发计划(2022YFC3005704)
国家自然科学基金面上项目(42277143)
四川省自然资源厅科研项目(KJ-2023-004,KJ-2023-029)。
关键词
崩塌
损伤基座
岩体劣化
离散元模拟
动力学特征
rock collapse
foundation damage
rock deterioration
discrete element modeling
kinematics characteristic
