橡胶砂泊松比试验研究  

Experimental study on Poisson's ratio of rubber-sand mixtures

作　　者：刘方成[1] 吴孟桃 刘娜[1] 张永富[1] 陈巨龙[1] 

机构地区：[1]湖南工业大学土木工程学院,湖南株洲412007

出　　处：《岩石力学与工程学报》2017年第A01期3596-3606,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51108177);湖南省自然科学基金资助项目(10JJ4040)~~

摘　　要：应用三轴试验方法,研究10种不同配比橡胶砂在4种围压下的泊松比变化规律,结果表明:(1)较低橡胶含量的橡胶砂泊松比变化规律与纯砂类似,由于剪胀效应的存在,泊松比出现大于0.5的情况,中等橡胶含量橡胶砂的泊松比随轴向应变或应力水平的增加而呈单调增加趋势,较高橡胶含量橡胶砂的泊松比呈先减小后增加的趋势;(2)橡胶砂初始泊松比随橡胶含量呈V型变化,先减小后增加,临界橡胶含量在35%~40%范围;(3)在破坏阶段橡胶砂泊松比趋于0.5;(4)围压对橡胶砂泊松比变化规律影响甚小。橡胶砂泊松比上述变化规律的主要力学机制是由于不同组分特征的橡胶颗粒与砂颗粒在混合物中形成不同的受力骨架。最后,提出橡胶砂泊松比随应力水平变化的经验估计式,与试验结果的对比证明其能反映橡胶砂泊松比的主要变化规律。Triaxial shear tests on RSM Poisson＇s ratio with 10 kinds of rubber content and four kinds of confining pressure are accounted. Results indicate that： （1） Poisson＇s ratio of RSM with low rubber content shows similar behavior with pure sand, and Poisson＇s ratio values greater than 0.5 is observed due to dilatancy effect. For RSM with medium rubber content, its Poisson＇s ratio increases with axial strain or stress level monotonically. For RSM with high rubber content, the Poisson＇s ratio of it decreases firstly and then increases with axial strain or stress level. （2） The initial Poisson＇s ratio of RSM shows V type variations with rubber content, that is it decreases first and then increases with the increase of rubber content of RSM, and the turnover rubber content is proved between 35 percent to 40 percent. （3） The Poisson＇s ratio of RSM approaches to 0.5 in damage stage. （4） Confining pressure influences RSM Poisson＇s ratio slightly. The mechanism of RSM Poisson＇s ratio variation with rubber content and stress level is attributed to different stress bearing skeleton form by sand or rubber particle in RSM mixtures. Finally, empirical equations for estimation of RSM Poisson＇s ratio dependent on stress level are proposed, and comparison with tests results demonstrates that the proposed equations could simulate RSM Poisson＇ ratio properly.

关 键 词：土力学 橡胶砂 泊松比 三轴试验 应力水平 经验公式 

分 类 号：TU43[建筑科学—岩土工程]