考虑边界约束影响的充填挡墙厚度确定方法及应力分布规律研究

Study on the Method for Determining the Thickness of Barricade and the Stress Distribution Law Considering the Influence of Boundary Constraints

不合理的边界加固方式会导致充填过程中挡墙边缘抗弯能力弱化进而影响采场安全。基于此,为了确定合理的充填挡墙厚度,探讨边界约束对充填挡墙稳定性的影响,将挡墙结构简化为4类薄板模型。以第一强度准则为判断依据,提出了不同边界约束模式下充填挡墙厚度确定方法。结合大冶铁矿工程实际,探讨了不同边界约束模式下充填挡墙应力分布规律,并通过解析几何和数值模拟对本文理论模型进行了验证。研究结果表明:①挡墙最小厚度与充填高度、充填料浆容重呈正相关关系,与挡墙抗拉强度呈负相关关系,增加挡墙抗拉强度有利于挡墙稳定性;②挡墙内外侧拉伸应力分布存在明显差异,外侧呈X型分布,内侧呈O型分布,边界抗弯能力弱化会导致拉伸区域拓展,增加挡墙边界弯矩可以有效防止挡墙破坏;③数值模拟获取的应力分布规律与解析几何分析结果高度一致,进一步验证了本文充填挡墙厚度确定方法的可靠性,结果可为类似采场充填挡墙参数优化提供参考。

Unreasonable boundary reinforcement methods can weaken the bending resistance of the barricade edges during the filling process,thereby affecting the safety of the mining site.Based on this,in order to determine the reasonable thickness of the filling barricade and explore the influence of boundary constraints on the stability of the filling barricade,the barricade structure is simplified into four types of thin plate models.Based on the first strength criterion,a method for determining the thickness of the filling barricade under different boundary constraint modes is proposed.Combined with the actual engineering situation of Daye Iron Mine,the stress distribution law of the filling barricade under different boundary constraint modes is discussed,and the theoretical model in this paper was validated through analytical geometry and numerical simulation.The result shows that:①The minimum thickness of the barricade is positively correlated with the filling height and the bulk density of the filling slurry,while negatively correlated with the tensile strength of the barricade.Increasing the tensile strength of the barricade is beneficial for its stability.②There is a significant difference in the distribution of tension stress on the inner and outer sides of the barricade,with the outer side in an X-shaped distribution and the inner side in an O-shaped distribution.The weakening of the boundary bending resistance will lead to the expansion of the tension area,and increasing the boundary bending moment of the barricade can effectively prevent the damage of the barricade.③The stress distribution law obtained from numerical simulation is highly consistent with the analytical geometric analysis results,further verifying the reliability of the method for determining the thickness of filling barricades in this paper.The results can provide reference for optimizing the parameters of barricades in similar mining areas.