加筋红土三轴试验与数值模拟研究  

Triaxial Test and Numerical Simulation on Reinforced Laterite

作　　者：朱俊涛 刘杰 罗凯 罗梦媛 邓世富 ZHU Jun-tao;LIU Jie;LUO Kai;LUO Meng-yuan;DENG Shi-fu(School of Civil and Hydraulic Engineering,Huazhong University of Science and Technology,Wuhan Hubei 430074,China;CCCC Second Navigation Engineering Bureau Co.,Ltd.,Wuhan Hubei 430074,China;Xinjiang Transport Planning Survey and Design Institute Co.,Ltd.,Urumqi Xinjiang 830006,China;Wuhan Municipal Construction Group Co.,Ltd.,Wuhan Hubei 430074,China)

机构地区：[1]华中科技大学土木与水利工程学院,湖北武汉430074 [2]中交第二航务工程局有限公司,湖北武汉430074 [3]新疆交通规划勘察设计研究院有限公司,新疆乌鲁木齐830006 [4]武汉市市政建设集团有限公司,湖北武汉430074

出　　处：《公路交通科技》2022年第7期55-65,83,共12页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51669031);新疆交通设计院科研基金项目(KY2019092504)。

摘　　要：为了研究土工织物加筋细粒红土的力学特性,制备了非饱和状态的红土试样。使用大型三轴仪,对不同加筋层数的红土在不同围压(30,50,100 kPa和150 kPa)及不同含水率(26.4%和34.4%)下进行三轴固结排水排气试验,并进行了数值模拟。通过有限元软件建立了二维模型模拟红土加筋前后三轴试验时土体的破坏状态,分析了其加筋机理及加筋后强度变化的内在原因。最后结合实际工程对加筋土挡墙进行了数值模拟,通过建立施工和运行时不同加载过程研究其工程特性。结果表明:加筋对红土的影响主要体现在抑制低围压下试样应变软化、增加试样延性和提升峰值强度3个方面,在试验的含水率范围内,加筋效果随土体含水率的增加而增加,随围压的增加而降低;界面的摩阻力使筋材附近一定范围内土体的应力场发生改变,增大了土体的小主应力,改变了土体的破坏模式,一定程度上提高了加筋土的整体强度,且加筋效果与红土的表观摩擦角有关,表观摩擦角越大,加筋红土的三轴压缩强度增大越明显;在保证一定的筋土界面强度的前提下,加筋可大大地提升高含水率加筋土挡墙的稳定性。In order to study the mechanical properties of geotextile reinforced laterite, unsaturated laterite samples are prepared. The triaxial consolidation drainage and exhaust tests on the laterites with different reinforced layers under different confining pressures(30, 50, 100, 150 kPa) and different moisture contents(26.4% and 34.4%) are carried out by using large-scale triaxial instrument, and the numerical simulation is carried out. A 2 D model is established by finite element software to simulate the failure states of the soil in the triaxial test before and after the laterite reinforcement, and the reinforcement mechanism and the internal reasons of the strength change after reinforcement are analyzed. Finally, the numerical simulation on the reinforced soil retaining wall is carried out in combination with actual engineering, and its engineering characteristics are studied based on the established different loading processes during construction and operation. The result shows that(1) The effect of reinforcement on laterite is mainly reflected in the suppression of the strain softening behavior under low confining pressure, the increase of ductility and the peak strength. Within the moisture content range of the experiment, the reinforcement effect increased with the increase of soil moisture content and decreased with the increase of confining pressure.(2) The frictional resistance of the interface changed the stress field of the soil within a certain range near the reinforcement, increased the small principal stress of the soil, changed the failure mode of the soil, and improved the overall strength of the reinforced soil to a certain extent. The reinforcement effect is related to the apparent friction angle of the laterite, the larger the apparent friction angle, the more obvious the increase of the triaxial compressive strength of the reinforced laterite.(3) On the premise of ensuring a certain strength of the reinforced soil interface, the reinforcement can greatly improve the stability of the reinforced so

关 键 词：道路工程 加筋红土 三轴试验 加筋机理 加筋土挡墙 

分 类 号：TU44[建筑科学—岩土工程]