扭剪荷载作用下饱和橡胶砂的动力学特性研究  

Dynamic behavior study of saturated rubber-sand mixture under torsional shear loading

作　　者：朱小军[1,2] 费康 Zhu Xiaojun;Fei Kang(School of Architechtual Science and Engineering,Yangzhou Unversity,Yangzhou 225127,China;Geotechnical Engineering Institute,Yangzhou University,Yangzhou 225127,China)

机构地区：[1]扬州大学建筑科学与工程学院,江苏扬州225127 [2]扬州大学岩土工程研究所,江苏扬州225127

出　　处：《建筑科学》2024年第9期32-39,共8页Building Science

基　　金：国家自然科学基金面上项目(51778557)。

摘　　要：为了研究橡胶颗粒与砂土混合物这种新型土木工程材料的动力学特性,将废旧轮胎颗粒与砂土混合制成橡胶砂混合土,并对其进行了空心扭剪试验研究。结果表明:低橡胶颗粒含量(R_(f)=5%~10%)的橡胶砂动孔隙水压力发展与纯砂类似,呈现“较快增长-线性增长-急剧增长”的发展模式,而较高橡胶颗粒含量(R_(f)=20%~30%)的橡胶砂动孔隙水压力呈现“快速增长-平稳”发展模式;橡胶砂液化周次随着橡胶含量的增加而增大,当R_(f)达到30%时,橡胶砂不发生液化破坏;橡胶砂在循环扭剪荷载下有效应力路径呈现三阶段发展,破坏时橡胶砂在剪缩和剪胀的两种状态中不断转换;橡胶砂应力应变滞回圈呈中心对称,随着橡胶颗粒含量的增加,滞回圈斜率逐渐减小,橡胶砂刚度降低;广义剪应变随着橡胶颗粒含量的增加逐渐减小,R_(f)=30%的橡胶砂抵抗变形能力最强;橡胶颗粒含量高的橡胶砂滞回圈面积较小,其更趋于弹性材料,有着更好的变形恢复能力,破坏需要的循环周期更长,其累积能量耗散更大。To study the dynamic characteristics of the rubber-sand mixture,a new type of civil engineering material,a series of hollow torsional shear tests are conducted on the rubber-sand mixture which is mixed with rubber particles from wasted tire and sand.The results show that the dynamic pore water pressure development pattern of rubber-sand mixture with low rubber content(R_(f)=5%~10%)is similar to pure sand,with a development pattern of"fast growth to linear growth to rapid growth".The dynamic pore water pressure of rubber-sand mixture with high rubber content(R_(f)=20%~30%)presents a"rapid growth to stable growth"development pattern.The liquefaction cycles of the rubber-sand mixture increase with the rubber content,and the rubber-sand mixture does not liquefy when R_(f)=30%.The effective stress path of rubber-sand mixture develops in three stages under cyclic torsional shear load,and the state of mixture changes constantly in shear shrinkage and shear dilatancy during the liquefaction process.The stress-strain hysteresis loop of the mixture is centrosymmetric,and the slope of hysteresis loop decreases gradually with the rubber content,which shows that the stiffness of mixture decreases.The generalized shear strain decreases with the rubber content,and the rubber-sand mixture with the 30%rubber content has the strongest resistance to deformation.The mixture with higher rubber content has a smaller hysteresis circle area,and the mixture tends to be elastic materials,with better deformation recovery ability,longer liquefaction period,and greater accumulated dissipated energy.

关 键 词：橡胶砂 空心扭剪试验 液化特性 能量耗散 橡胶颗粒含量 

分 类 号：TU435[建筑科学—岩土工程]