龙门黄河大桥左岸危岩体发育特征及其危险性预测  

Characteristics and Risk Assessment of Dangerous Rock on the Left Bank of Longmen Yellow River Bridge

作　　者：段素真 刘汉东[1] 王忠福[1] 何思明[2] 李冬冬[1] DUAN Suzhen;LIU Handong;WANG Zhongfu;HE Siming;LI Dongdong(North China University of Water Resources and Electric Power,Zhengzhou 450046,China;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China)

机构地区：[1]华北水利水电大学,河南郑州450046 [2]中国科学院山地灾害与环境研究所,四川成都610041

出　　处：《人民黄河》2022年第7期119-124,共6页Yellow River

基　　金：国家重点研发计划项目(2019YFC1509704);国家自然科学基金资助项目(U1704243)。

摘　　要：龙门黄河大桥位于晋陕两省交界处的黄河上,左岸桥台上方峭壁发育的大量危岩体对龙门黄河大桥的建设及正常运营构成极大威胁,开展危岩体稳定性评价和危险性预测具有重要的现实意义。基于地面调查和无人机摄影测量获取了危岩体控制性结构面信息、三维形态与几何尺寸,对其发育特征和潜在失稳模式进行分析。通过三维离散元法构建典型危岩体及地表三维数值模型,分析危岩体三维运移路径、冲击能量等,并提出了相应的防治措施。结果表明,危岩体可划分为上、中、下3个危岩带,岩性、地形、结构面是控制危岩体稳定的关键因素;潜在失稳模式可划分为倾倒式、坠落式、滑移式,危岩体失稳后对左岸桥台的冲击能量均超过10^(4)kJ,建议采用主动加固为主、被动防护为辅的综合防治措施。The Longmen Yellow RiverBridge is located on the Yellow River at the junction of Shanxi and Shaanxi provinces.A large amount of the unstable rock mass developed on the cliff above the bridge abutment has posed a great threat to the construction and operation of Longmen Yellow River Bridge.For this reason,it is of great importance to assess the stability of the unstable rock and forecast the hazard.Based on the high-precision three-dimensional digital terrain model obtained by unmanned air vehicle photogrammetry(UAV),the controlling structural surface information of the unstable rock mass was obtained.Combined with field survey,spatial distribution,shape,scale,the potential failure mode and formation mechanism of the unstable rock mass were identified and analyzed.A 3D numerical model of the unstable rock mass and surface morphology was constructed by using 3D discrete element method.The 3D path and impact energy of the moving unstable rock mass were analyzed.The results show that all the unstable rock mass can be divided into three zones in different elevations.Besides,under the control of lithology,topography,structural surface and other factors,the potential failure mode of the unstable rock mass can be divided into sliding type,topping type and falling type.The unstable rock mass mainly endangers the stability of the left bank abutment of the bridge,with an impact energy more than ten million Joules.In order to prevent such catastrophic failure,active and negative protective measures are recommended.

关 键 词：龙门黄河大桥 危岩体 失稳模式 危险性预测 

分 类 号：P642.22[天文地球—工程地质学]