黄土边坡悬臂式与全埋式单桩抗滑桩现场模型试验  

In-situ Model Test of Cantilever and Full-buried Anti-slide Single Piles in Loess Slope

作　　者：李哲[1] 朱振国 张娟[2] 曹升亮[2] LI Zhe;ZHU Zhen-guo;ZHANG Juan;CAO Sheng-liang(School of Highway,Chang'an University,Xi'an Shaanxi 710054,China;CCCC First Highway Consultants Co.,Ltd.,Xi'an Shaanxi 710075,China)

机构地区：[1]长安大学公路学院,陕西西安710054 [2]中交第一公路勘察设计研究院有限公司,陕西西安710075

出　　处：《公路交通科技》2020年第8期32-40,共9页Journal of Highway and Transportation Research and Development

基　　金：陕西省交通运输厅2016年度交通科研项目(16-18k KYHT 2017-18)。

摘　　要：以陕北地区G65w高速公路沿线边坡中的单排抗滑桩为研究对象,在高速公路黄土边坡上进行了悬臂式与全埋式单桩抗滑桩现场缩尺模型试验。研究悬臂式和全埋式两种不同的埋设条件下,单桩抗滑桩在滑坡推力作用下受力变形至破坏过程,测定水平加荷过程中的桩顶水平、竖向位移值,桩侧土压力分布形式以及桩身弯矩。并以位移结果确定抗滑桩的受力变形阶段。试验结果表明:根据位移结果,将模型桩受力过程划分3个阶段,即抗滑桩未变形阶段、抗滑桩有效变形阶段、抗滑桩失效阶段,3个阶段的分界点分别为临界启动荷载和临界阻滑荷载。两类模型桩均属塑性开裂的破坏模式,其中悬臂式模型桩为塑性单铰开裂破坏,破坏点约为桩的2/3处。全埋式模型桩存在两个开裂破坏点,分别在桩身约1/3和1/2处。全埋式模型桩的临界阻滑荷载为89 kN,比悬臂式的临界阻滑荷载(83 kN)高出约7.2%,且全埋式模型桩有更长的有效变形阶段。试验结果可为黄土边坡中两种埋设方式的抗滑桩的设计计算和破坏预警提供试验支持。Taking the single row anti-slide piles in the slope along the G65 w expressway in northern Shaanxi as the research object,the in-situ reduced-scale model tests on the cantilevered and full-buried single anti-slide piles in loess slopes of expressway are performed.The loading transfer processes and the failure modes of the single anti-slide piles under the action of landslide thrust under these 2 embedding conditions are studied.The horizontal and vertical displacements on the pile top,the soil pressure on pile side and the bending moment of pile shaft during horizontal loading are measured.The horizontal displacement on the pile top is used as a criterion to determine the loading deformation stage of the anti-slide piles.The result shows that(1)According to the displacement result,the stress process of the model piles is divided into 3 stages,including zero displacement stage,effective deformation stage and failure stage,and the dividing points of these 3 stages are the critical starting load and the critical anti-slide load.(2)Both cantilever pile and full-buried pile belong to the failure mode of plastic cracking.The cantilever pile is a plastic single hinge cracking failure,and the failure point is located at about 2/3 of the pile.While the full-buried pile exits 2 failure points,which are located at 1/3 and 1/2 of the pile.(3)The critical anti-slide load of the full-buried pile is 89 kN,which is about 7.2%higher than that of the cantilever type(83 kN).Compared with the cantilever pile,the full-buried pile has a longer stage of effective deformation.The test result can provide test support for the design,calculation and damage warning of the 2 anti-slide piles in the loess slope.

关 键 词：道路工程 黄土边坡 现场模型试验 抗滑桩 桩侧土压力 桩身弯矩 

分 类 号：U417[交通运输工程—道路与铁道工程]