循环荷载下桩承式路堤中土拱效应动力折减系数离散元研究  

Discrete Element Analysis on Dynamic Reduction Coefficient of Soil Arching Effect in Pile Supported Embankment under Cyclic Load

作　　者：崔晓艳[1,2,5] 庄妍 张希栋[3] 胡顺磊 程欣婷 CUI Xiaoyan;ZHUANG Yan;ZHANG Xidong;HU Shunlei;CHENG Xinting(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education(Southeast University),Nanjing 211189,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;College of Civil Engineering,Taiyuan University of Technology,Taiyuan 030024,China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;College of Transportation Engineering,Nanjing Technology University,Nanjing 210009,China)

机构地区：[1]混凝土及预应力混凝土结构教育部重点实验室(东南大学),江苏南京211189 [2]东南大学土木工程学院,江苏南京211189 [3]太原理工大学土木工程学院,山西太原030024 [4]河海大学土木与交通学院,江苏南京210098 [5]南京工业大学交通运输工程学院,江苏南京210009

出　　处：《湖南大学学报（自然科学版）》2022年第9期164-172,共9页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金优秀青年科学基金项目(51922029);国家自然科学基金资助项目(52178316,52108306);江苏省自然科学基金青年基金项目(BK20200372);中央高校基本科研业务费专项资金资助(2242021k30051)。

摘　　要：土拱效应是桩承式路堤中荷载传递的关键因素,其在循环荷载下的发挥程度与稳定性直接影响路堤的承载能力.基于室内土拱效应模型试验,采用PFC2D软件建立桩承式路堤颗粒流数值分析模型,并通过土拱效应室内模型试验结果验证了该离散元模型的正确性.基于该离散元数值分析模型,在路堤表面施加正弦波荷载模拟交通循环荷载,分析了循环动载作用下桩承式路堤中土拱效应的发展演变过程与衰减规律.数值模拟结果表明:路堤的高度与桩净间距的比值、动载振幅以及加载频率的改变均能影响土拱效应的发挥,但路堤的高度与桩净间距比值的变化对土拱效应动力折减系数的影响最大.路堤的高度与桩净间距的比值是影响动载作用下土拱效应稳定发挥的重要因素,将此因素考虑在内并对离散元数值模拟结果进行分析与曲线拟合,推求了土拱效应动力折减系数的表达式.Soil arching is the key factor of load transfer in a pile-supported embankment.Its development and stability under cyclic loading will directly affect the bearing capacity of the embankment.Based on the laboratory model test,a series of particle flow numerical models of the pile-supported embankment are established by using PFC2D software,and the correctness of the models is verified by the laboratory model test results.Based on the dis⁃crete element numerical models,the embankment is subjected to vehicle cyclic loads simulated by sinusoidal wave loads,and the development and reduction of soil arching in pile-supported embankment under cyclic loading are ana⁃lyzed.The numerical results show that the ratio of embankment height to pile spacing,cyclic load amplitude,and fre⁃quency all affect the soil arching in the piled embankment,while the variation of the ratio of embankment height to pile spacing significantly influences the soil arching reduction coefficient.The ratio of the embankment height to the pile spacing is an important factor affecting the stability of the soil arching in the piled embankment subjected to cy⁃clic load.Hence,the expression of the soil arching reduction coefficient is derived based on the analysis and curve fit⁃ting of discrete element numerical results by taking those factors into consideration.

关 键 词：路堤 土拱效应 数值模型 接触力分布规律 动力荷载 

分 类 号：TU443[建筑科学—岩土工程]