为分析覆岩多层薄采空区坚硬顶板条件下特厚煤层工作面的强矿压显现机理,合理确定工作面支架支护阻力,采用理论分析、相似模拟与现场实践相结合的研究方法,对特厚煤层开采条件下的多层顶板破断规律与工作面支架阻力确定问题进行了探讨,得出了工作面支架阻力确定原则与方法。研究表明:多层坚硬顶板的破断形式与破断次序对工作面矿压显现影响较为明显;关键层顶板的单层垮断或多层同步失稳将对应不同的工作面支架阻力;坚硬厚层顶板同步失稳条件下,单纯提高支架阻力将难以满足特厚煤层工作面合理支护要求。以大同矿区某煤矿工作面生产实际为背景,对特厚煤层工作面进行了支架合理选型同时配以坚硬顶板的水压致裂控制技术,取得了良好的顶板控制效果。
In this paper, to clarify the mining pressure behavior mechanism of the coal face in extra-thick coal seam under the multilayered hard overlying strata, and determine the support resistance reasonably, the multilayered roof breaking law and the support resistance in the extra-thick seam were studied, and the determination principle and calculation method of support resistance were obtained, by using the methods of theoretical analysis, similar simulation and field practice. The results show that the breaking form and breaking order of the multilayered hard roof have obvious influence on the mining pressure behavior, and the support resistances corresponding to single-layer key stratum caving and multi-layer stratum synchronous instability are different It will be difficult to meet the support requirements in extra-thick seam by simply improving the support resistance in the condition of multi-layer stratum synchronous instability. Take one coal face in Datong Mining Area for example, though the reasonable support selection in the extra-thick coal seam and using hydraulic fracturing technology for the hard strata, it has achieved good effect for roof control.