桩承式加筋土结构拓宽路基工作特性离心模型试验  

Centrifugal model test on the performance of pile-supported reinforced-earth structure for subgrade widening

作　　者：李立 曹文昭 刘洋 郑俊杰[1] 李波[3] LI Li;CAO Wenzhao;LIU Yang;ZHENG Junjie;LI Bo(Institute of Geotechnical and Underground Engineering,Huazhong University of Science and Technology,Wuhan,Hubei 430074,China;Central Research Institute of Building and Construction(Shenzhen)Co.,Ltd.,MCC Group,Shenzhen,Guangdong 518055,China;Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Yangtze River Scientific Research Institute,Wuhan,Hubei 430010,China)

机构地区：[1]华中科技大学岩土与地下工程研究所,湖北武汉430074 [2]中冶建筑研究总院(深圳)有限公司,广东深圳518055 [3]长江科学院水利部岩土力学与工程重点实验室,湖北武汉430010

出　　处：《岩石力学与工程学报》2021年第S02期3357-3366,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51808243,51878313,52078236)。

摘　　要：桩承式加筋土挡墙(PSRW)作为一种占地面积小、地基处理费用低和填料需求少的新型路基拓宽结构,已经被运用于高速公路拓宽改造。通过离心模型试验,针对既有路基有桩和无桩2种情况,分别采用桩承式加筋土挡墙结构与桩承式加筋路堤(GRPS)结构对路基进行拓宽,对比了4种工况,得到采用不同结构对路基进行拓宽后的外部变形和内部受力特征。结果表明:采用桩承式加筋土挡墙结构拓宽时,拓宽路基下地基土已完成大部分沉降,相比于未削坡且在原状地基土上建造的桩承式加筋路堤拓宽结构,具有更好的稳定性;采用桩承式加筋土挡墙结构对路基进行拓宽能有效减小路基顶面沉降;当既有路基设桩时,桩承式加筋路堤结构拓宽后的拓宽路基对地基中轴线处桩的作用远大于采用桩承式加筋土挡墙结构拓宽,而各桩桩身轴力则略小于采用桩承式加筋土挡墙结构拓宽。As a new kind of widening structure with smaller occupied area,lower cost of ground treatment and less requirement for fill,the pile-supported reinforced-earth wall(PSRW)has been used to widen the four-lane expressway.By means of centrifugal model test,both the PSRW and the geosynthetic-reinforced pile-supported embankment(GRPS)are used respectively to widen the existing subgrades that with or without piles.A total of 4 cases are selected and both the external deformation and internal stress characteristics after widening are obtained.The test results demonstrate that the PSRW has better stability than the GRPS when used for subgrade widening,because the GRPS widen subgrade built on the original subsoil without consolidation directly without slope cutting.Widening by PSRW can reduce the surface settlement of the subgrade effectively.When the existing subgrade with piles is widened by GRPS,the effect of widened subgrade on the piles at the central axis of subgrade is far greater than that of widened by PSRW,while the axial force of piles is slightly less.

关 键 词：桩基础 桩承式加筋土挡墙 桩承式加筋路堤 路基拓宽 离心模型试验 

分 类 号：TU47[建筑科学—结构工程]