玄武岩纤维尾砂充填体力学性能及损伤本构模型

Mechanical Properties and Damage Constitutive Models of Basalt Fiber Tailings Backfill

为了提高采空区充填体的力学性能,对加入玄武岩纤维的尾砂充填体进行抗压强度试验,研究不同纤维掺量、灰砂比和养护龄期对充填体的抗压强度影响规律,构建充填体损伤本构模型并分析其能量耗散规律。结果表明:玄武岩纤维的加入能够明显提高尾砂充填体的抗压强度,随着纤维掺量的增加,充填体的抗压强度呈先增大后减小的趋势,且最优掺量为0.4%,对比素尾砂充填体强度提升了13.277%~24.865%。纤维充填体峰后残余强度较高,引入损伤修正系数的损伤本构模型能合理表述纤维充填体峰后残余强度,根据损伤本构模型可得到充填体的峰值比能演算模型,适量掺加纤维可以提升充填体的峰值比能并减少能量耗散。玄武岩纤维能提高充填体的力学性能,强化矿山采空区充填效果。

In order to improve the mechanical property of tailings backfill in the goaf,compressive strength tests were conducted on the tailings backfill added with Basalt Fibers(BF).The effects of various BF content,cement-sand ratio and curing ages on the compressive strength of the tailings backfill were studied.Damage constitutive models of the tailings backfill were constructed.The energy dissipation laws of the tailings backfill were analyzed.The research results showed that the addition of BF can visibly enhance the compressive strength of the tailings backfill.With the adding of BF content,the compressive strength of the tailings backfill showed a tendency that first enhancing and then reducing.The optimal content of BF was 0.4%,which strength increased by 13.277%-24.865%as compared to the tailings backfill without BF.The residual strength of BF tailings backfill is stronger after the peak.The damage constitutive models that introduced a damage correction coefficient can reasonably describe the residual strength of BF tailings backfill after peak.According to the damage constitutive models,the peak specific energy calculation model of the tailings backfill was obtained.The peak specific energy of the tailings backfill showed the tendency of first enhancing and reducing later with the BF content.BF can improve the mechanical property of the tailings backfill and strengthen the filling effect of the goaf in mines.