巨厚煤层开采地表塔体稳定性难以保证,明确合理的开采方案已成为巨厚煤层高效开采与塔体稳定问题亟待解决的关键。以崔家沟煤矿转角塔下压煤开采2311工作面为工程背景,研究了厚硬覆岩条件下巨厚煤层开采对地表特殊结构转角塔塔线体稳定性的影响。研究结果表明:对于转角塔塔线体结构,水平移动和倾斜对各项力学性能影响最大。覆岩中硬覆岩占比过大导致沉陷系数取值存在特殊性。利用实测数据训练后的沉陷参数反演预测模型预测值准确度高。通过开采方案中限厚开采段长度及位置因素阐明了塔线体稳定性演化特征。其中限厚开采段长度及位置存在阈值,小于阈值均不能满足塔线体稳定性要求。不同采深下塔线体稳定性演化特征相似,但取值范围呈现非线性关系。研究对于相似塔下压煤开采、煤炭采出率提高以及沉陷控制具有指导意义。

Difficulty in ensuring the stability of surface towers after mining huge thick coal seams, and a clear and reasonable mining scheme has become the key to efficient mining and tower body stability of giant thick coal seams. Taking 2311 working face of corner tower under pressure coal mining in Cuijia- gou coal mine as the engineering background, the influence of mining of huge thick coal seam on the stability of surface special structure of corner tower under the condition of thick and hard overburden rock is studied. The results show that horizontal movement and inclination have the greatest influence on the mechanical properties of the corner tower line structure. The over-representation of hard overburden in the overburden rock leads to the specificity of the value of the subsidence coefficient. The inverse pre- diction model of subsidence parameters trained with measured data has high accuracy in predictingvalues. The stability evolution characteristics of the tower line body are elucidated by the length and loca- tion of the thickness-limiting section in the mining plan. Among them, there are threshold values for the length and location of the thickness-limiting section, and the stability requirements of the tower line body cannot be met even if they are smaller than the threshold values. The stability evolution characteristics of tower line body under different mining depths are similar, but the range of values shows a nonlinear rela- tionship. The study is of guiding significance for the pressure coal mining under similar towers, the im- provement of coal extraction rate and the control of subsidence.