双向循环荷载下橡胶砾石-土工格栅界面剪切特性  

Shear characteristics of rubber gravel geogrid interface under bidirectional cyclic loading

作　　者：张大伟 钱振豪 冯忞 刘飞禹[2] ZHANG Dawei;QIAN Zhenhao;FENG Min;LIU Feiyu(Shanghai Pudong Architectural Design and Research Institute Co.,Ltd.,Shanghai 201206,China;School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海浦东建筑设计研究院有限公司,上海201206 [2]上海大学力学与工程科学学院,上海200444

出　　处：《振动与冲击》2025年第2期199-209,共11页Journal of Vibration and Shock

基　　金：国家自然科学基金(52378355,52078285)。

摘　　要：橡胶颗粒与土体混合可作为构筑物基础的轻质填料,并能提高其抗震性能。利用室内动态直剪仪进行了一系列循环荷载下的直剪试验,分析了橡胶砾石颗粒级配、法向循环荷载、循环剪切频率对土工格栅-橡胶砾石界面的剪切应力-剪切位移关系和体变特性。试验结果表明:4种颗粒级配界面剪切应力均随着循环次数的增加而增大,表现出剪切硬化的特征,界面竖向位移也随之增大,表现出剪缩的特征;4种级配土中级配良好GR2表现出最高的界面抗剪强度,其界面最终剪缩量最小;当法向和水平加载频率一致时,界面循环峰值剪切应力随着频率的增加而增大,当法向和水平加载频率不一致时,滞回曲线根据法向和水平加载频率的大小呈现周期性变化;在同一颗粒级配下,筋土界面剪切刚度和界面阻尼比均随着法向循环荷载的增加而增大,界面剪切刚度随着循环次数的增加而增大,界面阻尼比则相反。Rubber granules mixed with soil can be utilized as a lightweight filler to enhance seismic performance.A series of direct shear tests were conducted using a custom-built dynamic direct shear apparatus.The analysis focused on examining the shear stress-shear displacement relationship and the volumetric change characteristics of the geogrid-rubber gravel interface with the change of the rubber gravel particle gradation,normal cyclic loading,and cyclic shear frequency.The test results show that the interfacial shear stress with the four kinds of granular gradation increases with the increase of the number of cycles,showing the characteristics of shear hardening,and the interface vertical displacement also increases,showing the characteristics of shear shrinkage.Among the four kinds of graded soils,the well-graded GR2 demostrates the highest interfacial shear strength and the least final shear shrinkage.When normal and horizontal loadings are applied,the interfacial shear stress-shear displacement relationship and body transformation characteristics of the geogrid-rubber gravel interface keep unchanged.When the normal and horizontal loading frequencies are consistent,the peak interfacial cyclic shear stress escalates with the frequency,when the normal and horizontal loading frequencies are inconsistent,the hysteresis curve varies according to the higher of the normal and horizontal loading frequencies.In the condition of the same particle gradation,the interfacial shear stiffness and the interfacial damping ratio of the tensile soil increase with the increase of normal cyclic load.The interfacial shear stiffness increases with the increase of the number of cycles,on the contrary,the damping ratio demonstrates an opposite trend.

关 键 词：岩土工程 橡胶砾石 双向循环荷载 橡胶含量 颗粒级配特征 动力特性 

分 类 号：TU411.7[建筑科学—岩土工程]