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橡胶砂作为轻质耗能填料在土木工程中应用越来越广泛,土工格室加筋可提高橡胶砂的抗剪强度和整体稳定性。针对关于橡胶砂或加筋橡胶砂动力特性的认知缺乏的现状,通过大尺寸循环单剪试验研究了橡胶砂分别在有无土工格室加筋情况下在水平循环荷载作用下的滞回特性。获得了加筋和非加筋橡胶砂的滞回曲线、动剪模量曲线和阻尼比曲线,并应用Stokeo–Darendeli模型对橡胶砂动力特性进行拟合,得到了加筋和非加筋橡胶砂的动力特性参数。基于对比分析,揭示了土工格室对橡胶砂动力特性影响的规律与机理。试验结果表明:(1)土工格室加筋能限制橡胶砂中剪切带的发展,使得橡胶砂在大应变下的滞回曲线反S形特征减弱、阻尼比增大;(2)由于网兜效应引起颗粒接触法向应力增大,土工格室加筋使橡胶砂动剪模量增大,且随着橡胶含量的增高而增大愈明显;(3)土工格室的加入降低了循环加载次数对橡胶砂动力特性的影响,并使得橡胶砂最大动剪模量随橡胶含量和竖向压力变化的速率减小。给出的土工格室加筋对橡胶砂动力特性影响的定量分析结果,可为后续研究和工程应用提供参考。
As a light-weight energy-saving filler, rubber sand is more and more widely used in civil engineering. Geogrid reinforcement can improve the shear strength and overall stability of rubber sand. In view of the lack of knowledge about the dynamic characteristics of rubber sand or reinforced rubber sand, the hysteretic behavior of rubber sand under horizontal cyclic loading with or without geogrid reinforcement . Obtained the hysteresis curve, the dynamic shear modulus curve and the damping ratio curve of the reinforced and unreinforced rubber sands, and the dynamic characteristics of the rubber sand were fitted by using the Stokeo-Darendeli model to obtain the reinforced and non-reinforced rubber sand Dynamic characteristics of the parameters. Based on the comparative analysis, the rules and mechanism of the influence of geocell on the dynamic characteristics of rubber sand were revealed. The results show that: (1) geocell reinforcement can limit the development of shear zone in rubber sand, which makes the rubber sand anti-S-shaped characteristics of hysteretic curve under large strain weakened and the damping ratio increases; (2) The effect of the particles caused by the normal contact stress increases, geocell reinforcement rubber sand dynamic shear modulus increases, and with the rubber content increases and more obvious; (3) Geocell added to reduce the cycle load Frequency on the dynamic characteristics of rubber sand and makes the maximum dynamic shear modulus of rubber sand decreases with the rubber content and vertical pressure changes. The results of quantitative analysis of the influence of geogrid reinforcement on the dynamic characteristics of rubber sand can provide a reference for subsequent research and engineering application.