粉细砂填料土工格室柔性挡墙工程性状研究  

Engineering Behaviors of Geocell Flexible Retaining Wall with a Fine Sand Backfill

作　　者：杨晓华[1] 李浩[1] 曾浩 孔永博 晏长根[1] YANG Xiao-hua;LI Hao;ZENG Hao;KONG Yong-bo;YAN Chang-gen(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;Sichuan Road and Bridge(Group)Co.Ltd.,Chengdu 610000,Sichuan,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]四川公路桥梁建设集团有限公司勘察设计分公司,四川成都610000

出　　处：《中国公路学报》2023年第6期24-35,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(42077265)。

摘　　要：以孟加拉达卡绕城公路项目为依托,通过模型试验和数值模拟对以粉细砂为填料的土工格室柔性挡墙工程性状进行了研究。模型试验结果表明:柔性挡墙墙背土压力近似“R”形分布,墙身水平位移为“鼓形”分布,在墙高H/2处墙背土压力明显减小且墙身水平位移最大,水平位移最大值为66 mm;土工格室壁应变曲线呈反“S”形分布,在墙高H/2以下时,格室壁最大应变面从墙趾到墙背线性发展,与水平面的夹角为34°,墙高H/2以上时,格室最大应变面沿墙背发展,柔性挡墙的潜在破裂面即格室壁最大应变的连线。在此基础上,通过有限元软件ABAQUS研究了不同墙宽B、坡率R、高宽比H/B及格室间距和地基模量下柔性挡墙的受力变形特性,数值模拟结果表明:墙宽与最大高度成正比,坡率与最大高度成反比,墙宽2 m的最大高度为7.3~8.5 m,墙宽3 m的最大高度为8.1~9.8 m,墙宽4 m的最大高度与墙宽3 m接近,介于8.2~10.2 m之间。高宽比增大时,墙身水平位移和挠曲变形均变大,且最大位移点随墙高的增加由H/2逐渐降低到距墙底约H/3;土工格室层的间距与墙身水平位移成正比,与墙背土压力成反比,格室层的最大间距不宜超过格室高度的75%;地基模量的降低使柔性挡墙破坏模式变成了外部失稳的整体滑动,墙身水平位移和墙背土压力由非线性分布变成近似线性分布,滑动面切过墙后填土及地基土,墙身水平位移最大点出现在墙顶处。试验结果可为柔性挡墙设计提供参考。The characteristics of a geocell flexible retaining wall with fine sand backfill,based on the Dhaka Ring Road in Bangladesh,were studied using a model test and numerical simulations.The model test results indicate that the distribution of earth pressure pattern against the back of the flexible retaining wall was of“R”type,while the distribution of horizontal displacement resulted in a“drum”pattern.While the earth pressure was decreasing,the horizontal displacement was greatest at H/2 of the wall,which was 66 mm.The strain distribution at the geocell was found as an inverse“S”shape.The maximum surface strain of the cell developed linearly from the toe of the wall to the back of the wall below H/2,inclined at an angle of 34°to the horizontal plane,and this surface developed along the wall back to the top of the wall above H/2.The potential failure surface of the flexible retaining wall can be interpreted as the line of the maximum strain on the cell.Based on the model test results,Abaqus software was used to analyze the geocell retaining wall characteristics depending on different widths B,slope rates,ratios of height to width H/B,geocell spacing,and foundation modulus.The simulation results show that the maximum height was proportional to the wall width and inversely proportional to the slope rate.The maximum height for wall width of 2 m was 7.3-8.5 m,for width of 3 m was 8.1-9.8 m,and for width of 4 m was 8.2-10.2 m,which was close to the maximum height of wall with the width of 3 m.When H/B increased,both horizontal displacement and deflection increased,and the position of maximum horizontal displacement moved from H/2 to H/3 of the wall.The spacing of geocell layers was found to be proportional to the horizontal displacement and inversely proportional to the earth pressure on the back of the wall.Therefore,the maximum spacing of the cell layers should not exceed 75%of the cell height.The failure mode of the retaining wall was global sliding when the foundation modulus decreased,the sliding surface

关 键 词：道路工程 柔性挡墙 模型试验 土工格室 数值模拟 

分 类 号：U417.1[交通运输工程—道路与铁道工程]