School of Energy and Mining Engineering, China University of Mining and Technology-Beijing, Beijing, China.
PLoS One. 2022 Oct 18;17(10):e0276101. doi: 10.1371/journal.pone.0276101. eCollection 2022.
In order to assess the rationality of the rated shield support capacity (RSSC) experienced selection and guide the reasonable RSSC selection for the subsequent working faces of each coal seam, the coupling relationship between shield and roof strata was revealed during each coal seams mining. According to whether the fractured rock blocks generated by the main roof are articulated and whether the upper coal seam has been mined and influenced on the lower coal seam, two roof structure mechanical models of the rock blocks generated by the thick main roof and two calculation methods of a given load on the rock blocks are proposed. In addition, a selection method of roof structure model for maximum shield support capacity (MSSC) of close-multiple coal seams with the coordinated mining is put forward. Three roof structures to calculate the MSSC are established. Based on a case study of close-multiple coal seams with the coordinated mining in the Qianjiaying coal mine, the MSSC is calculated and analyzed in each coal seam combined with roof structure characteristics description, theoretical analysis, and field measurement. No.7, No.12-1, and No.5 coal seams mining are applicable to a voussoir beam balanced structure. No.8 coal seam mining is applicable to a balanced structure with a given load of loose body. No.9 coal seam mining is applicable to a voussoir beam balanced structure with a given load of loose body. Through the calculation, the MSSC of No.7, No.8, No.12-1, No.9, and No.5 coal seam is 3948.55kN, 4018.32kN, 4101.63kN, 3560.03kN, and 4015.30kN, respectively. And the RSSC suggested selection of each coal seam is 4500kN, 4300kN, 4300kN, 4000kN, and 4300kN, respectively. By field measurement, the RSSC experienced selection of each coal seam in the Qianjiaying coal mine is unreasonable with low support load utilization. However, after adopting the RSSC suggested selection in each coal seam, the support load utilization increased by 29.07%, 9.6%, 8.57%, 15.33%, and 11.39%.
为了评估已经验证的额定护盾支撑能力（RSSC）的合理性，并指导后续每个煤层工作面的合理 RSSC 选择，揭示了每个煤层开采过程中护盾与顶底板岩层的耦合关系。根据主顶板产生的破碎岩块是否铰接以及上煤层是否已开采并对上煤层产生影响，提出了厚主顶板产生的岩块两种顶板结构力学模型和两种给定岩块上载荷的计算方法。此外，还提出了协调开采近距离多煤层最大护盾支撑能力（MSSC）的顶板结构模型选择方法。建立了三种计算 MSSC 的顶板结构。以钱家营煤矿近距离多煤层协调开采为例，结合顶板结构特征描述、理论分析和现场实测，计算分析了各煤层的 MSSC。7 号、12-1 号和 5 号煤层开采适用于楔梁平衡结构。8 号煤层开采适用于松散体给定载荷的平衡结构。9 号煤层开采适用于松散体给定载荷的楔梁平衡结构。通过计算，7 号、8 号、12-1 号、9 号和 5 号煤层的 MSSC 分别为 3948.55kN、4018.32kN、4101.63kN、3560.03kN 和 4015.30kN，各煤层建议 RSSC 选择分别为 4500kN、4300kN、4300kN、4000kN 和 4300kN。现场实测表明，钱家营煤矿各煤层 RSSC 经验选择不合理，支撑载荷利用率低。然而，在采用各煤层建议 RSSC 选择后，支撑载荷利用率提高了 29.07%、9.6%、8.57%、15.33%和 11.39%。
