摘要
湖北省秭归县黄家沟危岩体作为三峡库区典型的临江高陡危岩体,发育在九畹溪右岸陡崖绝壁上,其失稳崩塌引发涌浪将对九畹溪航道和九畹溪景区的安全运营构成严重威胁。基于详细的野外调(勘)查工作,查明黄家沟危岩体的工程地质条件和基本特征,对其成因机制和失稳破坏模式进行分析研究;通过赤平投影法对危岩带整体宏观稳定性进行定性判别,采用刚体极限平衡模型量化评估危岩单体在不同工况下的稳定性;最后根据危岩体空间分布特征、潜在失稳破坏模式及现场施工条件,提出合理的防治工程设计方案。研究表明,黄家沟危岩体发育两级危岩带,包含4处危岩单体和1处破碎带,其中各危岩单体分属小—大型高位危岩,破坏模式分为滑移式、倾倒式和坠落式;该危岩体危害程度等级为Ⅱ级。多级陡崖带地形地貌、上硬下软的地层岩性组合、构造与结构面组合切割等控制因素决定了危岩体的边界条件和潜在失稳破坏类型;库水位涨落、大气降水、植物根劈、温差效应等诱发因素叠加触发了危岩体的失稳破坏进程。各危岩单体在天然工况下处于稳定—基本稳定状态,在暴雨工况下处于基本稳定—欠稳定状态,需要进行治理。最终提出了不稳定块体清除+锚固+主动柔性防护网安装+裂缝封闭及凹腔填充+消落区护面+监测的综合防治方案。该研究成果可为三峡库区类似危岩体的风险防控与工程治理提供科学参考。
As a typical riverside high-steep unstable rock mass in the Three Gorges reservoir area,the Huangjiagou unstable rock mass in Zigui County,Hubei Provnce is developed on the cliff on the right bank of Jiuwanxi River.The surge caused by its instability and collapse will pose a serious threat to the safe operation of Jiuwanxi channel and Jiuwanxi scenic spot.Based on the detailed field investigation(exploration)work,the engineering geological conditions and basic characteristics of Huangjiagou unstable rock mass were identified,and its genesis mechanism and instability failure mode were analyzed.The overall macroscopic stability of the unstable rock belt was qualitatively judged by the red flat projection method,and the stability of the unstable rock monomer under different working conditions was quantitatively evaluated by using the rigid body limit equilibrium model.Finally,according to the spatial distribution characteristics of unstable rock mass,potential instability failure mode and on-site construction conditions,a reasonable design scheme of prevention and control project is proposed.The research shows that Huangjiagou unstable rock mass develops a two-level dangerous rock belt,including four unstable rock monomers and one fracture zone.Each unstable rock monomer belongs to small-large high unstable rock collapse,and the failure mode is divided into slip type,toppling type and falling type.The hazard degree of the unstable rock mass is gradeⅡ.The boundary conditions and potential instability failure types of unstable rock mass are determined by the control factors such as the topography of multi-level cliff zone,the lithology combination of upper hard and lower soft strata,and the combination cutting of structure and structural plane.The superposition of reservoir water level fluctuation,atmospheric precipitation,plant root splitting,temperature difference effect and other inducing factors triggers the instability and failure process of unstable rock mass.Each unstable rock monomer is in a stable-basic stable state under natural conditions,and is in a basic stable-unstable state under heavy rain conditions,which needs to be treated.Finally,a comprehensive prevention and control scheme of unstable block removal+anchorage+active flexible protection network installation+crack closure and rock cavity filling+water-level-fluctuating zone protection surface+monitoring is proposed.The research results can provide a scientific reference for the risk prevention and control and engineering management of similar unstable rock masses in the Three Gorges Reservoir area.
作者
廖祥东
张俊辉
李永辉
罗顺林
李云
彭耀
张汉林
Liao Xiangdong;Zhang Junhui;Li Yonghui;Luo Shunlin;Li Yun;Peng Yao;Zhang Hanlin(Wuhan Hydrogeology and Engineering Geology Brigade,Hubei Geological Bureau,Wuhan 430051,China;Wuhan Geological Engineering Investigation Institute Co.,Ltd.,Wuhan 430051,China)
出处
《资源环境与工程》
2025年第6期759-770,共12页
Resources Environment & Engineering
基金
湖北省三峡库区后续规划地质灾害防治项目(ZGGJS0449-202401-01)。
关键词
三峡库区
危岩体
稳定性评价
失稳破坏模式
防治工程设计
Three Gorges Reservoir area
unstable rock collapse
stability evaluation
instability failure mode
prevention engineering design
