橡胶砂液化特性的动扭剪试验研究

Dynamic torsional shear test study on liquefaction characteristics of rubber-sand mixture

为研究橡胶砂的液化特性,在不同的橡胶质量掺量、循环应力比、相对密实度、频率和有效围压工况条件下对橡胶砂进行动扭剪试验,分析橡胶砂的动力剪切应力-应变关系、动弹性模量和阻尼比的发展趋势.结果表明:橡胶颗粒质量掺量越高,橡胶砂越不易液化,广义剪切应变越小,橡胶砂越不易破坏;在橡胶颗粒掺量一定的情况下,试样破坏周次随循环应力比增大而减少;相对密实度和有效围压增大时,试样的剪切应变降低、抗液化能力增强,而剪切频率增大时,抗液化能力减弱;随着剪切应变和橡胶颗粒掺量的增加,试样弹性模量逐渐降低,阻尼比逐渐增大.

In order to study the liquefaction characteristics of rubber sand,the dynamic torsion shear tests of rubber sand are carried out under different conditions of rubber mass content,cyclic stress ratio,relative compaction,frequency and effective confining pressure.The variation trend of dynamic shear stress-strain relationship,dynamic elasticity modulus and damping ratio of rubber-sand mixture are analyzed.The results show that the higher the content of rubber particles,the less liquefaction of rubber sand;the smaller the generalized shear strain,the less damage of rubber sand.Under the condition of the same rubber content,the failure cycle of the mixture decreases with the cyclic stress ratio.When the relative compactness and effective confining pressure increase,the mixture shear strain decreases and the liquefaction resistance increases.But the liquefaction strength of mixture decreases with the shear frequency.With the increase of shear strain and rubber content,the elastic modulus of the mixture decreases gradually,while the damping ratio increases gradually.