土工格栅加筋橡胶砂强度特性试验研究

橡胶砂作为轻质、耗能填料在土木工程中有广泛的应用前景，但其强度往往会随橡胶含量的增大而降低。土工格栅常用于对散体材料的加筋补强，研究土工格栅对橡胶砂强度特性的加筋效应具有重要意义。基于三轴压缩试验，对3种不同格栅布置方式（1、2、3层）下的干燥橡胶砂强度特性展开研究，重点考察加筋层数对不同围压（50、100、200 kPa）下、不同配比（0%、10%、20%、30%、40%）橡胶砂的强度参数，如峰值强度、似黏聚力、内摩擦角的影响规律。结果表明：土工格栅加筋橡胶砂的强度参数，包括峰值强度、似黏聚力、内摩擦角，相对于未加筋橡胶砂均有明显提高，提高幅度随土工格栅加筋层数的增加而增大，随着围压的降低而增大；土工格栅对配比为20%橡胶砂的强度加筋效应最为明显；土工格栅加筋橡胶砂的强度参数恢复系数与加筋密度之间呈良好的线性关系；土工格栅加筋橡胶砂的强度特性可由试验所得的经验恢复函数较好地估计。

Experimental study of strength characteristics of geogrid reinforced rubber sand mixtures

Rubber-sand mixture (RSM) has long been recognized as a light weight and energy absorbing material with widely usage in civil engineering. Shear strength of RSM usually decreases with inclusion of rubber particles. As geogrid is usually used to improve the shear strength of granular materials, it is of great interesting to find out how geogrid affect the strength of RSM when RSM is reinforced by geogrid. Triaxial tests were carried out on dry RSMs to study the influence of reinforcing geogrid layers on the strength parameters, such as peak deviatoric stress, pseudo cohesive strength and internal friction angle. Five rubber contents (0%, 10%, 20%, 30% and 40%) and three confining pressures (50 kPa, 100 kPa, 200 kPa) were taken into accounted in tests. Test results indicate that peak deviatoric stress, pseudo cohesive strength and internal friction angle of RSMs reinforced by geogrid are significantly improved comparing to those of RSMs without geogrid. These parameters increase with the increase of the number of geogrid reinforcement layers and with the decrease of confining pressure. The reinforcing effect on strength of RSM by geogrid reaches a peak when the rubber content is 20%. The strength recovery coefficients of geogrid reinforced RSMs exhibit linear relations with the reinforcement density of geogrid, and can be estimated well by the empirical curves of this study.