窄煤柱沿空掘巷非对称支护力学特征与支护参数研究
Study on mechanical characteristics and supporting parameters of asymmetric support in gob-side entry driving with narrow coal pillar
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摘要: 为了研究窄煤柱沿空掘巷非对称支护下围岩变形与应力分布特征, 采用理论分析方法, 研究窄煤柱沿空巷道对称支护与非对称支护力学机理; 基于马道头煤矿现场工程实践, 采用数值模拟与工程效验方法, 研究非对称支护下巷道围岩力学特征与稳定性。理论分析结果表明, 非对称支护可有效降低巷道顶板弯矩, 减小巷道顶底板与两帮变形量。模拟结果表明, 煤柱内部压应力增高区与弹性核区保障了煤柱承载性能。现场实测结果表明, 采用“锚索+槽型钢”非对称支护, 巷道顶板、窄煤柱侧巷帮与实体煤侧巷帮最大变形量分别为100、79、62 mm, 巷道松动圈与裂隙发育处于中等水平。Abstract: In order to study the deformation and stress distribution characteristics of surrounding rock under the asymmetric support of gob-side entry driving with narrow coal pillar, the theoretical analysis method was used to study the mechanical mechanism of symmetrical and asymmetric support of gob-side entry driving with narrow coal pillar. Based on the field engineering practice of Madaotou Coal Mine, the mechanical characteristics and stability of roadway surrounding rock under asymmetric support were studied by combination of numerical simulation and engineering effect verification methods. The theoretical analysis show that the asymmetric support can effectively reduce the bending moment of the roadway roof and reduce the deformation of the roadway roof and floor and the two sides. The simulation results show that the internal stress-concentrated area and elastic core zone in the coal pillar ensure the bearing performance of the coal pillar. The field measurement results show that under the asymmetric support of "anchor cable+channel steel", the maximum deformation of roadway roof, narrow coal pillar side, and solid coal side is 100 mm, 79 mm, 62 mm, respectively. Besides, the development of roadway loose zone and the fissure is at a medium level.