Wu Pengfei, Zhao Jihe, Jin Jiaxu
Liaoning Technical University, Fuxin, 123000, China.
Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai, 200000, China.
Sci Rep. 2023 Aug 2;13(1):12550. doi: 10.1038/s41598-023-39782-3.
The method of filling mining can solve the problem of surface subsidence caused by coal mining. Among them, it is crucial to study the mechanism of filler strength improvement timeliness and filler mining to control rock movement for filler mining. In this paper, by combining theoretical analysis and similar simulation experiments, compressive strength is used as the research parameter to conduct proportioning test research on paste filling similar materials such as coal gangue, fly ash, and cement. The results prove that the strengths of the test ratios can meet the strength design criteria and lay the foundation for the requirements of similar simulation experiments. In order to study the characteristics of overburden failure, stress and displacement in the process of filling mining, the key technical parameters of overburden movement are determined. Similar simulation experiments were conducted to study the movement and deformation of overburden rock and the displacement and stress distribution law of overburden rock in the coal mine under different filling rates and filling steps conditions. The results show that the filling rate and filling step are the keys to preventing the overlying rock from rupture and collapse, and the larger the filling rate is, the smaller the stress and displacement of the overburden; the larger the filling step is, the larger the displacement and stress change of the overburden, and vice versa. In addition, the displacement curve along the strike is basically an "arch" type distribution, and the stress variation trend is "large-small-large" with a "Z" type distribution. The research results are of great significance to guide the practice of filling mining and can provide the theoretical basis for its further promotion.
充填开采方法能够解决煤炭开采引起的地表沉陷问题。其中，研究充填体强度提高时效性及充填开采控制岩层移动的机理对于充填开采至关重要。本文通过理论分析与相似模拟试验相结合的方式，以抗压强度作为研究参数，对煤矸石、粉煤灰、水泥等似膏体充填相似材料进行配比试验研究。结果表明，试验配比的强度能够满足强度设计标准，为相似模拟试验要求奠定了基础。为研究充填开采过程中覆岩破坏、应力及位移特征，确定了覆岩移动关键技术参数。通过相似模拟试验研究了不同充填率和充填步距条件下煤矿覆岩的移动变形情况以及覆岩位移和应力分布规律。结果表明，充填率和充填步距是防止上覆岩层破裂冒落的关键，充填率越大，上覆岩层的应力和位移越小；充填步距越大，上覆岩层的位移和应力变化越大，反之亦然。此外，沿走向的位移曲线基本呈“拱形”分布，应力变化趋势为“大-小-大”呈“Z”型分布。研究成果对指导充填开采实践具有重要意义，可为其进一步推广提供理论依据。
