掺聚丙烯纤维尾砂充填体损伤及能量演化特征

为了探究掺聚丙烯纤维充填体在受载状态下的损伤特性及能量演化规律，对掺不同质量含量的聚丙烯纤维充填体进行单轴压缩试验，得到了掺不同纤维含量充填体优化后的本构模型。研究结果表明:向充填体添加聚丙烯纤维能够有效的提高充填体的力学性能，当纤维含量达到0.6%时，纤维增强充填体的效果最好；对现有的掺纤维充填体损伤本构理论模型进行优化，得到了优化后掺聚丙烯纤维充填体理论曲线，并将理论曲线与试验曲线和文献曲线进行对比验证，发现优化后的理论曲线与试验曲线拟合度更高；构建了损伤与应变能之间的关系，损伤-应变能关系曲线能更好描述掺不同纤维含量充填体的损伤特性，发现纤维增强充填体力学特性的主要机理，即纤维不仅增强了充填体储存应变能的能力，还增大了充填体峰后储能的能力。试验结果对科学指导井下矿体安全开采及充填体灾害预防具有一定意义。

Damage and Energy Evolution Characteristics of Polypropylene Fiber Mixed Tailings Backfill

In order to explore the damage characteristics and energy evolution law of the polypropylene fiber filling body under load, uniaxial compression tests were carried out on the polypropylene fiber filling body with different mass contents, and the optimized constitutive model of the polypropylene fiber filling body with different content was obtained.The results show that adding polypropylene fiber to backfill can effectively improve the mechanical properties of backfill. When the fiber content reaches 0.6%, the effect of fiber reinforced backfill is the best.The existing damage constitutive theory model of the fiber doped filling body was optimized, and the theoretical curve of the optimized polypropylene fiber filling body was obtained. The theoretical curve was compared with the experimental curve and the literature curve, and it was found that the optimized theoretical curve and the experimental curve had a higher fitting degree.The relationship between damage and strain energy was established.The damage-strain energy relationship curve could better describe the damage characteristics of filling body mixed with different contents of fiber, and the main mechanism of fiber enhancement of physical characteristics of filling was found, that is, fiber not only enhanced the capacity of filling body to store strain energy, but also increased the capacity of post-peak energy storage of filling body.The test results have certain significance for scientific guidance of safe mining of underground ore body and disaster prevention of backfill body.