动力湿化作用下压实红黏土累积变形规律与控制研究  

Accumulative deformation law and control of compacted lateritic soil under coupled action of wetting and dynamic loading

作　　者：刘维正[1,2] 黄轩嘉 徐阳 李慧丽 万家乐 LIU Weizheng;HUANG Xuanjia;XU Yang;LI Huili;WAN Jiale(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-Speed Railway Construction Technology,Changsha 410075,China;Hunan Provincial Communications Planning,Survey&Design Institute Co.,Ltd.,Changsha 410203,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]湖南省交通规划勘察设计院有限公司,湖南长沙410203

出　　处：《岩土工程学报》2025年第3期535-547,共13页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金面上项目(52078500);中国中铁股份有限公司科技研究开发计划项目(2021-专项-08);中国国家铁路集团有限公司科技研究开发计划实验室基础研究项目(L2023G002)。

摘　　要：针对南方多雨地区在役红黏土路基易发生湿化,并在交通荷载联合作用下产生过大附加变形问题,开展了不同含水率的静三轴试验以及不同湿化次数、幅度和动应力的动三轴试验,分析含水率变化对黏聚力和内摩擦角的影响,探究动应力幅值、湿化次数和幅度对累积变形以及动回弹模量的影响规律,并建立了考虑动应力幅值、湿化次数和幅度、黏聚力和内摩擦角的累积变形预测模型;基于谱元法建立了移动荷载下红黏土路基横观各向同性动力响应计算模型,通过与现场行车试验结果对比验证了解析模型的有效性,并分析了湿化与动荷载作用下路基顶面竖向压应变规律。结果表明:累积塑性应变随动应力幅值、湿化次数和幅度的增加呈非线性增大;动回弹模量随初始含水率和湿化次数的增加而减小;湿化3次后的路基顶面竖向压应变增长约一倍。进而建立了路基顶面竖向压应变与累积应变的经验关系,结合现有规范给出了红黏土路基累积应变控制值,提出了红黏土路基变形控制方法,并在某高速公路试验段通过水泥改良强化路床和动回弹模量试验验证了所提方法的可行性。研究结果可为红黏土地区耐久性路基的设计和服役性能评价提供参考。To address the problem that the in-service lateritic soil subgrade is prone to wetting and excessive additional deformation under the combined effects of traffic loading in southern rainy areas of China,the static triaxial tests with different moisture contents and the dynamic triaxial tests with different wetting times,wetting amplitudes and dynamic stresses are conducted.The effects of varying moisture contents on the cohesive force and angle of internal friction are analyzed,and the influences of dynamic stress amplitude,wetting times and wetting amplitude on the accumulative deformation and dynamic resilient modulus are investigated.A model for predicting the accumulative deformation is established by considering the dynamic stress amplitude,times and amplitude of wetting,cohesive force and angle of internal friction.Based on the spectrum method,a model for transverse isotropic dynamic response of lateritic soil is established.The validity of the analytical model is verified by comparing with the results of the field vehicle tests,and the law of vertical compressive strain on the top of subgrade is analyzed under the effects of wetting and dynamic loading.The results show that the accumulative plastic strain increases nonlinearly with the increasing dynamic stress amplitude,wetting times and wetting amplitude.The dynamic resilient modulus decreases with the initial moisture content and the wetting times.The vertical compressive strain on the top of subgrade increases approximately double after wetting of three times.The empirical relationship between the vertical compressive strain on the top of subgrade and the accumulative strain is established,and the control value of accumulative strain is proposed in combination with the existing specification of the permissible value of accumulative deformation of subgrade,which gives the controlling method for the deformation of lateritic soil subgrade.The proposed method is verified by the cement-treated upper roadbed filler and the dynamic resilient modulus tests in

关 键 词：红黏土 动力湿化 抗剪强度 累积变形 动回弹模量 预测模型 变形控制 

分 类 号：TU416[建筑科学—岩土工程]