橡胶砂弹性动力学参数的弯曲-伸缩元试验研究

橡胶砂作为一种廉价环保的土工材料,应用前景十分广阔,关于其力学特性的研究具有重要意义。采用弯曲–伸缩元法对橡胶砂进行了剪切波和压缩波联合测试,分别采用离散频率扫描法和初达波法确定了剪切波和压缩波的传播时间,进而得到其弹性动力学参数:初始剪切模量、侧限模量和泊松比,分析了橡胶含量和围压对橡胶砂弹性动力学参数的影响。结果表明:在同样围压下,随着橡胶含量的增加,橡胶砂初始剪切模量和侧限模量逐渐减小,初始泊松比逐渐增大;在同样橡胶含量下,随着围压的增大,橡胶砂初始剪切模量和侧限模量逐渐增大,初始泊松比逐渐减小。最后,在此基础上进行了两种因素耦合效应的分析以及相关力学机制的探讨。

Laboratory study on elastic dynamic mechanics of rubber-sand mixture by bender-extender element method

Rubber-sand mixture, as a kind of low-cost and environmental protection geotechnical material, has broad applications, and the research on its mechanical properties is of great significance. In this study, the combined test of shear wave and compression wave for rubber-sand mixture is carried out by bender-extender element method. The propagation time of shear wave and compression wave is determined by discrete frequency scanning method and initial arrival wave method, respectively. After that, the elastic dynamic parameters such as initial shear modulus, constrained modulus and Poisson's ratio, are obtained. The influence of rubber content and confining pressure on elastic dynamic parameters of rubber-sand mixture is analyzed as well. The results show that under the same confining pressure, with the increase of rubber content, the initial shear modulus and constrained modulus of rubber-sand mixture gradually decrease, and the initial Poisson's ratio gradually increases. Under the same rubber content, with the increase of confining pressure, the initial shear modulus and constrained modulus of rubber-sand mixture gradually increase, and the initial Poisson's ratio gradually decreases. Finally, the coupling effect of the two factors and the related mechanical mechanism are analyzed.