法向循环荷载下筋土界面细观剪切特性分析  

Mesoscopic Study on the Shear Process of Reinforcement Soil Interface Under Normal Cyclic Loading

作　　者：冯忞 FENG Min(Shanghai Pudong Architectural Design and Research Institute Co.,Ltd.,Shanghai 201204,China)

机构地区：[1]上海浦东建筑设计研究院有限公司,上海201204

出　　处：《华南地震》2024年第4期126-133,共8页South China Journal of Seismology

基　　金：国家自然科学基金资助项目(51678352)。

摘　　要：为深入研究动荷载下筋土界面特性和加筋机理,以室内试验结果为基础,利用离散元软件建立了法向循环荷载下格栅—砾石界面直剪试验数值分析模型,分析了法向循环荷载作用下筋土界面剪切过程的细观机理,探究了剪切过程中筋土界面颗粒受力演化规律。结果表明:在界面剪切试验过程中,筋土界面由峰值前较小的变形,逐淅软化形成局部变形集中的剪切带,且厚度约为平均粒径的7~9倍;力链随剪切的进行趋于稳定,形成贯通的强力链;循环荷载下的孔隙率变化曲线在相应上、下界静荷载试验之间,而配位数接近或低于下界荷载的结果。In order to further study the interface characteristics and reinforcement mechanism of reinforced soil under dynamic load,based on the laboratory test results,a numerical analysis model of direct shear test of geogrid-gravel interface under normal cyclic load was established by using discrete element software.The meso-mechanism of the shear process of reinforced soil interface under normal cyclic load was analyzed,and the evolution law of particle force at reinforcement-soil interface during shear process was explored.The results show that in the process of interface shear test,the interface between reinforcement and soil changes from small deformation before the peak value to gradually soften to form a shear band with local deformation concentration,and the thickness is about 7-9 times of the average particle size.The force chain tends to be stable with the shearing process,forming a strong chain;the porosity change curve under cyclic loading is between the corresponding upper and lower bound static load tests,and the coordination number is close to or lower than the result of the lower bound load.

关 键 词：法向循环荷载 直剪试验 筋土界面 细观特征 

分 类 号：TU432[建筑科学—岩土工程]