橡胶颗粒-砂混合物侧限压缩试验研究

Study on Laterally Confined Compression Test of Rubber-Sand Mixtures

对7种不同橡胶质量分数的干燥橡胶砂进行了侧限压缩试验,考虑了12级竖向应力对其压缩特性的影响。试验结果表明：1）橡胶砂的回弹量、弹塑性应变以及总应变均随橡胶质量分数的增加而变大;竖向应力相同时,橡胶砂的累积沉降量、孔隙比、压缩系数均随橡胶质量分数的增加而增加;橡胶质量分数相同时,橡胶砂的累积沉降量、密度、压缩模量均随竖向应力的增大而增大,且塑性应变大于弹性应变;这些变化特性,橡胶砂比纯砂颗粒明显,纯橡胶颗粒比橡胶砂显著。2）纯砂颗粒和橡胶质量分数为1 0%的橡胶砂,其e-lo g（p）曲线具有线性回归特性,两者的线性拟合斜率较小且相近;橡胶质量分数为20%~50%的橡胶砂以及纯橡胶颗粒试样,其e-log（p）曲线近似线性特性,其线性拟合斜率随橡胶质量分数的增加而变大,且相同橡胶质量分数试样的e-log（p）曲线的分段斜率随竖向应力对数值的增大而变大。3）橡胶砂和纯橡胶颗粒试样的压缩系数-竖向应力段曲线,表现出非线性特性,这种非线性随橡胶砂中橡胶质量分数的增大越来越显著。4）相同竖向应力段的压缩模量随橡胶质量分数的增加呈指数衰减,且竖向应力段越大,衰减越明显。

Conducted a series of laterally confined compression tests on rubber-sand mixtures of 7 different rubber mass fractions, in which considering the impact of 12 levels vertical pressure on the compression properties of the mixtures.Results of the tests indicate that： 1） The springback, the elastic-plastic strain and the total strain of rubber-sand mixtures increase with the increment of rubber mass fractions. When vertical pressure are the same, the cumulative settlement, the void ratio and the compression coefficients of rubber-sand mixtures increase with the increment of rubber mass fractions.When rubber mass fractions are the same, the cumulative settlement, the density and the compression modulus of rubbersand mixtures increase with the vertical pressure increment, and its plastic strains are larger than its elastic strains. These change characteristics of rubber-sand mixtures are more obvious than that of pure sand particles and are less distinct than that of pure rubber particles. 2） The e-log（p） curves of the pure sand particles and the rubber-sand mixtures of 10% rubber mass fraction have the characteristics of linear regression,and their linear fitting slopes are small and close. The e-log（p）curves of the pure rubber particles and the rubber-sand mixtures of 20% to 50% rubber mass fraction approximate linear characteristics, and their linear fitting slopes increase with the increment of rubber mass fractions. The subsection slope of e-log（p） curves increase with the vertical stress logarithm value increasing when rubber mass fractions are the same. 3） The compression coefficient-vertical stress section curves of the pure rubber particles and rubber-sand mixtures exhibit nonlinear characteristics, it is more and more obvious with the rubber mass fraction increasing. 4） Compression modulous of the same vertical stress sections decays with rubber mass fractions increasing, and the greater the vertical stress section, the more obvious the attenuation.