高填方路堤滑坡成因分析及防护对策  

Analysis and countermeasures of landslides in high fill embankments

作　　者：王鹏[1,2] 杨龙伟 李永勤 李小兵 赵冬 WANG Peng;YANG Long-wei;LI Yong-qin;LI Xiao-bing;ZHAO Dong(CCCC First Highway Consultants Co.,Ltd.,Xi’an 710075,Shaanxi,China;Xi’an CCCC Highway Geotechnical Engineering Co.,Ltd.,Xi’an 710075,Shaanxi,China;CCTEG Wuhan Engineering Company,Wuhan 430064,Hubei,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,陕西西安710075 [2]西安中交公路岩土工程有限责任公司,陕西西安710075 [3]中煤科工集团武汉设计研究院有限公司,湖北武汉430064

出　　处：《地基处理》2024年第S01期95-102,110,共9页Journal of Ground Improvement

摘　　要：以某高速公路互通匝道高填方路堤边坡失稳为例,综合考虑填方区原始地形地貌、地层岩性及施工工艺对路堤边坡稳定性的影响,分析了土−岩二元结构填方边坡的变形特征和破坏机理,认为岩土界面可能为填方边坡的最薄弱层面而非填筑界面。同时,根据滑坡成因分析和稳定性评价结果,借助ABAQUS有限元分析软件对填方边坡的破坏机理做了进一步验证,并对抗滑桩支挡结构的受力状态进行了数值分析。分析可知,滑坡滑面主要在岩土界面处,滑面形态呈折线状;通过开挖台阶、设置宽平台和抗滑桩支挡可有效抑制路堤边坡变形,同时应加强排水;在抗滑桩支挡作用下,高填方路堤边坡潜在滑动面表现为由深层向浅层的演化破坏;滑动面以上桩身应力逐渐减小,在滑面处形成“三角状”高应力区,滑动面以下桩−土接触段桩身应力主要集中在桩前;桩身主要受弯段在潜在滑面以下;桩身主要受推力部位在滑面以上桩长1/5~1/3处,而主要抗力部位在滑面以下桩前部分。Taking the instability of a high fill embankment slope at a highway interchange ramp as an example,this study comprehensively considers the influence of original terrain topography,geological lithology,and construction technology on the stability of embankment slopes.It analyzes the deformation characteristics and failure mechanism of the soil-rock binary structure embankment slope,suggesting that the rock-soil interface may be the weakest zone of the embankment slope rather than the fill interface.Besides,based on the landslide analysis and instability evaluation,the failure mechanism of the fill slope was further verified by ABAQUS finite element analysis software,and the stress state of the anti-slide pile support structure was analyzed.It is concluded that the sliding surface of the landslide is mainly located at the rock-soil interface,and exhibits a polyline shape.Applying bench excavation,wide platforms,and anti-slide pile support can effectively suppress the deformation of embankment slopes,while drainage measures should be strengthened.Under the action of anti-slide pile support,the potential sliding surface of the high fill embankment slope exhibits evolutionary failure from deep to shallow layers.The stress on the pile body above the sliding surface gradually decreases,forming a“triangular”high stress zone at the sliding surface.The stress of the pile body in the pile-soil contact section below the sliding surface is mainly concentrated in front of the pile.The main bending section of the pile body is below the potential sliding surface.The main thrust area of the pile body is 1/5-1/3 of the pile length above the sliding surface,while the main resistance area is in the front part of the pile below the sliding surface.

关 键 词：高填方路堤边坡 成因分析 稳定性评价 数值分析 抗滑桩 

分 类 号：U41[交通运输工程—道路与铁道工程]