尾矿砂钢纤维喷射混凝土在铁矿巷道中的应用

为了解决铁矿巷道开采过程中采用尾矿砂钢纤维喷射混凝土作为巷道单层衬砌的应用问题,以尾矿砂取代天然河砂作为细骨料配制钢纤维喷射混凝土,并对不同钢纤维掺量的喷射混凝土进行了抗压、抗折、劈拉等力学性能试验,得到了喷射混凝土的最优配比及钢纤维掺量对混凝土的影响.采用ANSYS对铁矿软弱岩层进行数值模拟分析,探讨了最佳衬砌厚度下巷道开挖后的计算结果,通过分析获得了尾矿砂钢纤维喷射混凝土的合理喷层厚度.结果表明,混凝土中钢纤维的掺入量为40 kg/m3时混凝土的力学性能达到最佳,并且混凝土的密实性、耐久性和质量稳定性亦有所加强,但抗压强度的提高不十分明显.

Application of tailing sand steel fiber sprayed concrete in iron mine tunnel

In order to solve the application problem of tailing sand steel fiber sprayed concrete as the single layer lining of tunnel in the mining process of iron mine tunnel, the tailing sand was used to replace the natural river sand, and was taken as the fine aggregate to prepare the steel fiber sprayed concrete. In addition, such mechanical performance tests as the compressive, flexural and splitting tests were performed for the sprayed concrete with different steel fiber contents, and the optimal proportion of sprayed concrete and the influence of steel fiber contents on the concrete were determined. The numerical simulation analysis for the soft surrounding rock of iron mine was carried out with ANSYS software, the calculation results after the excavation of iron mine tunnel under the optimal lining thickness were discussed, and the reasonable shotcrete thickness of tailing sand steel fiber sprayed concrete was obtained through the analysis. The results show that when the steel fiber content in the concrete is 40 kg/m³, the concrete has the optimal mechanical properties, and the compactibility, durability and quality stability of concrete also get enhanced. However, the increase in the compressive strength is not obvious.