基于砾钢渣+橡胶颗粒的新型填料动剪切模量与阻尼比特性试验

为了解决固体废弃物循环利用问题，提出将废旧轮胎橡胶颗粒掺入废弃钢渣中形成新型土工填料。为了了解该新型填料的动力特性，采用共振柱试验对基于钢渣+橡胶颗粒的新型土工填料的动剪切模量和阻尼比特性开展研究。首先分析围压与橡胶颗粒含量对新型填料动剪切模量和阻尼比的影响，试验结果表明：动剪切模量和阻尼比与剪应变的关系类似传统土类，动剪切模量随着剪应变的增大而减小，阻尼比则随着剪应变的增加而增大，变化曲线趋势基本一致；新型填料的动剪切模量随着钢渣含量的减少和橡胶颗粒含量的增加而逐渐减小，橡胶颗粒含量达到20%时，动剪切模量与剪应变的关系曲线低缓显著，新型填料中橡胶颗粒不宜掺入太多。然后，基于Hardin-drnevich双曲线模型建立新型填料的动力特性理论模型，Hardin-drnevich双曲线模型能够较好地模拟新型填料动剪切模量归一化的数据，并对新型填料参考剪应变随橡胶含量的变化趋势进行了预测。最后，将新型填料的最大动剪切模量与纯钢渣、南京砂和福建标准砂的最大动剪切模量进行比较。分析结果表明：新型填料的橡胶颗粒含量不宜超出15%，这种新型填料动剪切模量适中，阻尼比较大，具有较好的抗震减震能力，能够替代砂土成为一种回填材料。

Experiment of Dynamic Shear Modulus and Damping Ratio of New Geo-filler Composed of Gravel Steel Slag and Rubble Particles

To solve the problem of the recycling of industrial solid wastes, a new type of geo-filler was developed that was composed of rubber particles and waste steel slag. The dynamic characteristics of the new geo-filler were examined through resonant column tests. The effects of confining pressures and rubber particle corporation ratios were analyzed on the dynamic shear modulus and damping ratio of the new geo-filler. The relationship between the dynamic shear modulus and shear strain as well as that between the damping ratio and shear strain of the new geo-filler are found to be similar to those of traditional soils. The dynamic shear moduli decrease and the damping ratios increase with increasing shear strain, and the vibration trend of the relationship curves is coincident. The dynamic shear moduli decrease with increasing rubber particle content and decreasing steel slag content. When the rubber particle content of the new geo-filler is 20%, the relationship curves between the dynamic shear modulus and shear strain clearly decline. This reveals that the rubber particle content of the new geo-filler cannot be too high. The Hardin-Drnevich model was applied to describe the dynamic model of new geo-filler and could simulate the dynamic data very well. In addition, the tendency distributions of reference strains of the new geo-filler were predicted by changing the rubber corporation ratios. The maximum dynamic shear moduli of the new geo-filler were compared with steel slag, Nanjing sand, and standard sand. The results show that the highest corporation ratio of rubber particles in the new geo-filler is 15%. When the corporation ratio of rubber particles is not greater than 15%, the dynamic shear moduli of the new geo-filler is moderate and the damping ratios are relatively large. These results indicate that the new geo-filler has better seismic resistance and damping capacity and can thus be used as a backfill material to replace sand.