花岗岩残积土-土工格栅界面的后循环剪切行为研究

摘要

Granite residual soil is widely distributed in southern China,southeast coast,Southern mountain,and Xinjiang area etc.Previous studies mainly focus on its structural and microscopic properties and rarely involved post cyclic loading,displacement evolution,soil density and other factors.Reinforcement-soil interface shear properties and reinforcement effect of impact are assessed by above-mentioned factors.From cycle test the shear stiffness of this important parameter start to loads,the loading times,loading frequency,displacement amplitude,soil bulk density values to independent variables,by applying control variable method through the design of cyclic direct shear test,this paper acquired the shear stress and shear displacement relationship curves,vertical displacement and shear displacement relationship curves of reinforced granite residual soil were observed and compared.The results show that half displacement amplitude and soil dry bulk density have great influence on the granite residual soil-geotechnical grille interface shear stiffness,while loading frequency has little influence,and the cyclic loading is not weakened after the interfacial shear strength,shear displacement and semi-displacement amplitude is negatively correlated.%花岗岩残积土在华南、东南沿海、南岳、新疆等地区广泛分布,前人的研究多集中在结构性及微观特性上,后循环加载、位移演化、土壤密度等因素对筋-土界面的剪切特性及加筋作用效果的影响评估研究较少.从循环试验剪切刚度这一重要参数人手,以加载次数、加载频率值、位移振幅值、土壤重度值为自变量,应用控制变量法,通过设计循环直剪试验,得到加筋花岗岩残积土的剪切应力与剪切位移、垂直位移与剪切位移关系曲线进行观察对比,结果表明:花岗岩残积土土工格栅界面剪切刚度受位移半振幅、土壤干重度影响很大,受加载频率影响很小,循环加载并没有弱化后循环界面剪切强度,剪切位移与位移半振幅呈负相关关系.