大同煤田同忻矿可采煤层顶板力学性质及其对开采的影响

矿井生产过程中,顶板事故频发,对煤矿安全生产威胁巨大,有必要明确煤层顶板力学性质和稳定性。本次研究以大同煤田同忻矿为研究对象,收集钻孔地质资料,总结了各可采煤层厚度特征和空间展布特征,确定了各煤层顶板类型；采集各煤层顶、底板岩心样品,以岩石力学测试实验为手段,得出了顶、底板岩石的抗压强度、抗拉强度和抗剪强度等力学参数,明晰了煤层顶板岩石类型和稳定性,并针对此提供了相应建议。结果表明,研究区发育山2^#、山4^#、2^#、3-5^#、8^#和9^#煤层共6套可采煤层,其中太原组3-5^#和8^#煤层为主采煤层；山2^#煤层顶板多为中硬岩,稳定性相对较好,山4^#煤层顶板类型多为直接顶和老顶,伪顶区域小规模存在,多为中硬岩和硬岩,稳定性较好；2^#煤层可采区域顶板类型主要为直接顶和老顶,软岩—坚硬岩皆有分布；3-5^#煤层顶板类型区域内以直接顶为主,大面积连片分布,伪顶和老顶穿插分布,主要为软—中硬岩；8^#煤层顶板类型多为直接顶和老顶,伪顶罕见,软-中硬岩皆有存在；9^#煤层顶板类型伪顶、直接顶和老顶穿插分布,软岩—中硬岩皆有发育。研究结果对于研究区矿井安全开采有一定的参考价值。

The Roof Mechanical Properties and its Influence on Mining of the Minable Coal Seam of the Tongxin Mine in the Datong Coalfield

In the process of coal mine production, roof accidents occur frequently, which threaten the safety of coal mine production, it is necessary to make clear the mechanical properties and stability of coal seam roof. In this study, Tongxin coal mine in Datong coalfield is taken as the research object, the geological data of borehole are collected, the thickness characteristics and spatial distribution characteristics of each minable coal seam are summarized, and the roof types of each coal seam are determined; By means of rock mechanics test, the mechanical parameters such as compressive strength, tensile strength and shear strength of the roof and floor rocks are obtained, and the types and stability of the roof rocks of the coal seam are clarified, and the corresponding suggestions are provided. The results show that, in the study area, 6 sets of minable coal seams are developed, among them, the 3-5^# and 8^# coal seams of Taiyuan formation are main coal seam; The roof types of Shan4^# are mostly direct roof and old roof, mostly medium hard rock and hard rock, with good stability; 2^# coal seam are mainly direct roof and old roof, both soft rock and hard rock are distributed; 3-5^# coal seam are mainly direct roof, with a large area of continuous distribution, and the pseudo roof and old roof are interspersed, mainly soft medium Hard rock; 8^# coal seam roof types are mostly direct roof and old roof, and pseudo roof is rare, soft medium hard rock exists; 9^# coal seam roof types are pseudo roof, direct roof and old roof, and soft medium hard rock develops. The research results have certain reference value for the mine safety mining in the research area.