西藏某陡顺倾岩质边坡变形破坏机制分析  

ANALYSIS OF DEFORMATION AND FAILURE MECHANISM OF STEEP BEDDING ROCK SLOPE

作　　者：孙巍锋 赵冠华[4] 兰恒星 晏长根[5] 包含[5] 刘世杰[1] 吴兴建 SUN Weifeng;ZHAO Guanhua;LAN Hengxing;YAN Changgen;BAO Han;LIU Shijie;WU Xingjian(School of Geological Engineering and Geomatics,Chang'an University,Xi'an 710054,China;Center for Post-doctoral Studies of Geological Resources and Geological Engineering,Chang'an University,Xi'an 710054,China;Key Laboratory of Ecological Geology and Disaster Control,Xi'an 710054,China;State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;School of Highway,Chang'an University,Xi'an 710064,China;Shaanxi Expressway Testing&Measuring Co.,Ltd.,Xi'an 710086,China)

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]长安大学地质资源与地质工程博士后科研流动站,西安710054 [3]生态地质与灾害防控重点实验室,西安710054 [4]中国科学院地理科学与资源研究所,资源与环境信息系统国家重点实验室,北京100101 [5]长安大学公路学院,西安710064 [6]陕西高速公路工程试验检测有限公司,西安710086

出　　处：《工程地质学报》2025年第1期341-355,共15页Journal of Engineering Geology

基　　金：青藏高原二次科考项目(资助号:2019QZKK0904);国家自然科学基金项目(资助号:42307217,41941019);中央高校基本科研业务费(资助号:300102262901);新疆阿乌阿公路发展有限责任公司科研项目(资助号:AWAGSGCJS-23-ZXFWHT-003);陕西省重点研发计划项目(资助号:024SF-YBXM-553).

摘　　要：为揭示西藏陡顺倾岩质边坡变形破坏机制,结合现场边坡调研与InSAR分析揭示了边坡变形时空规律,从定性与力学角度分析了边坡变形破坏机制与临界条件。研究结果表明:垂直开挖高度较大且岩性较差边坡区有显著的岩层外鼓、坡面片状剥落、岩层缺失与裂隙发育现象,表明曾产生岩层滑塌破坏且稳定性欠佳;在植被生长、枝叶掉落、卸荷回弹、积雪覆盖与冻胀等影响下,坡顶自然斜坡区出现了最大介于30~40 mm的正变形区,而在卸荷、降雨、气温与片状剥落等影响下,边坡开挖区坡面则出现了最小介于-30~-20 mm的负变形区;监测点变形量历时曲线类型可分为上升型、稳定型与下降型3大类,且上升型与下降型曲线还可分别细分3个亚类与4个亚类;开挖前后的边坡经历了卸荷回弹阶段、岩层塑性变形阶段与岩层压坏滑移阶段,而缺失岩层归因于坡脚因蠕变被压缩破坏后引发的上部岩层剪切滑移;开挖区坡面一些监测点变化表现出不稳定蠕变曲线的迹象,为防止边坡主控岩层在极端降雨或强震下可能产生破坏,宜采用锚杆、锚索或削坡对危险岩层进行加固处理;推导了主控岩层压应力与临界自稳高度的理论解析式,临界自稳高度与单轴抗压强度、相邻主控岩层间抗剪强度参数成正比,而与地震加速度以及主控岩层的倾角、密度与厚度成反比。研究结果可为类似陡顺倾岩质边坡成灾的机制认识与稳定分析提供一定参考。To reveal the deformation and failure mechanisms of steep bedding rock slopes in Xizang,the temporal and spatial patterns of slope deformation were analyzed through a combination of field slope investigations and InSAR analysis.The deformation and failure mechanisms,as well as the critical conditions for slope instability,were examined from both qualitative and mechanical perspectives.The research results indicate significant phenomena such as rock bulging,flaking,missing rock layers,and crack development in areas with high vertical excavation heights and poor lithology,suggesting that rock collapse and instability have occurred in the past.Under the influence of vegetation growth,fallen branches and leaves,unloading rebound,snow cover,and frost heave,a maximum positive deformation zone ranging from 30 mm to 40 mm appeared in the natural slope area at the top of the slope.Conversely,due to unloading,rainfall,temperature fluctuations,and rock flaking,a minimum negative deformation zone ranging from-30 mm to-20 mm was observed on the slope surface in the excavation area.The deformation duration curves of monitoring points were classified into three categories:upward,stable,and downward.The upward and downward curves were further subdivided into three and four subcategories,respectively.The slope underwent several stages before and after excavation:unloading rebound,rock plastic deformation,and rock compression sliding.The missing rock layer was attributed to shear sliding of the upper rock layer caused by compression failure at the base of the slope due to creep.Some monitoring points on the slope surface in the excavation area exhibited signs of unstable creep.To prevent damage to the main rock layers of the slope under extreme rainfall or strong seismic events,it is recommended to use anchor rods,anchor cables,or slope cutting to reinforce the dangerous rock layers.A theoretical analytical formula for the compressive stress of the main control rock layer and the critical self-stabilizing height was derived.The cr

关 键 词：陡顺倾岩质边坡 变形破坏机制 INSAR 岩层压应力 临界自稳高度 

分 类 号：P554[天文地球—构造地质学]