采煤工作面顶板初次垮落判识的数值分析

Numerical Analysis of Identification of Initial Roof Caving of Working Face

本文以河南义马矿区千秋煤矿21221工作面为工程背景,建立了采煤工作面顶板发生初次垮落的超静定梁力学模型,揭示了顶板初次垮落超静定梁两端三自由度受限时的力学机理,推导了超静定梁的应力分布演化方程,计算了考虑限制三自由度的顶板初次垮落极限步距。通过FLAC^(3D)建立了与理论模型相对应的采煤工作面顶板初次垮落数值模型,根据初次垮落极限步距理论解模拟了工作面动压影响下顶板位移的演化和顶板初次垮落过程,模拟结果与实验结果基本相符合。本文的研究可为同类煤矿工作面上覆岩层运动和垮落研究提供数值分析理论基础。

In this paper,the mechanical model of the statically indeterminate beam for the initial roof caving of the working face is established,the mechanical mechanism of the initial roof caving when the three degrees of freedom at both ends of the statically indeterminate beam are limited is revealed,the stress distribution evolution equation of the statically indeterminate beam is deduced,and the limit step of the initial roof caving considering the restriction of three degrees of freedom is calculated by taking the working face 21221 of Qianqiu Coal Mine in Yima mining area of Henan Province as the engineering background. The numerical model of the initial caving of the working face corresponding to the theoretical model is established through FLAC^(3D),the evolution of roof displacement and the initial roof caving process under the influence of dynamic pressure are simulated according to the theoretical solution of the initial caving limit step,and the simulation results are generally consistent with the experimental results. The research of this article can provide a theoretical basis for numerical analysis of overburden movement and collapse in similar working faces.