近距离煤层群下行开采遗留煤柱下巷道布置优化与支护技术OA
Optimization of roadway layout and support technology under residual coal pillars for the downward mining in close-distance coal seam groups
针对近距离煤层群巷道布置难题,聚焦下行开采中上部采空区遗留煤柱应力集中及大埋深含夹矸复杂条件下的围岩控制困境,采用耦合夹矸影响的多工作面动态开挖数值模拟与现场工程验证相结合的方法,建立"上部煤柱-夹矸-下部巷道"三维耦合模型,设计内错、错距0 m、外错(10～60 m梯度)多组布置工况,分析应力传递路径与围岩变形规律,据此提出支护优化技术方案并开展工业性试验.结果表明:受4#煤层夹矸阻隔影响,上部26 m遗留煤柱底板应力在夹矸层内衰减形成"应力缓冲带",煤柱正下方应力集中系数降至1.8,底板应力呈现"煤柱正下方高集中-采空区中部次高-边界低应力"的空间分布特征,采空区底板最大破坏深度达20.29 m;外错40 m时巷道顶底板垂直应力峰值降低42％,顶底板与两帮移近量分别降至0.04 m和0.276 m,较内错及错距0 m布置更优;"空间错距动态调控-支护结构协同优化"一体化技术路径配套联合支护体系,使巷道顶底板变形进一步减少60％、两帮变形减少17.9％;巷道变形、围岩应力及支护受力的实测值与模拟值相对误差均≤7％,优化方案使巷道维护成本降低28％,无片帮、冒顶等围岩失稳现象.研究可为近距离煤层群下位巷道的合理布置与精准支护提供参考.
To address the challenges in roadway layout of close-distance coal seam groups,particularly the stress concentration from residual coal pillars in upper goafs during downward mining and the sur-rounding rock control under complex conditions of large burial depth and intercalated gangue,a com-bined approach of numerical simulation of multi-face dynamic excavation considering gangue influence and on-site engineering verification was adopted.A three-dimensional coupled model of"upper coal pillar-gangue intercalation-lower roadway"was established,and multiple layout scenarios were de-signed,including inner-offset,0 m offset,and outer-offset(with a gradient of 10～60 m).The stress transfer paths and surrounding rock deformation laws were analyzed,an optimized support technical scheme was proposed,and industrial tests were conducted.The results indicate that:Affected by the ob-struction of the gangue in the 4#coal seam,the stress in the floor of the remaining 26 m upper coal pil-lar attenuates within the gangue layer,forming a"stress buffer zone",and the stress concentration factor directly below the coal pillar decreases to 1.8.The floor stress exhibits a spatial distribution character-istic of"high concentration directly under the coal pillar-sub-high in the middle of the gob-low stress at the boundary".The maximum damage depth of the goaf floor reaches 20.29 m.When the outer offset is 40 m,the peak vertical stress of the roadway roof and floor decreases by 42％,and the convergence of the roof-floor and two sides reduces to 0.04 m and 0.276 m,respectively,which is superior to the lay-outs of inner-offset and 0 m offset.The integrated technical path of"dynamic regulation of spatial offset distance collaborative optimization of support structure"combined with the joint support system further reduces the roof-floor deformation by 60％and the two-side deformation by 17.9％.Meanwhile,the relative errors between the measured values and simulated values of roadway deformation,surrounding rock stress,and support force are all≤7％.The optimized scheme reduces the roadway maintenance cost by 28％,and no surrounding rock instability phenomena such as rib spalling or roof collapse oc-cur.The research results can provide reference for the reasonable layout and precise support of lower roadways in close-distance coal seam groups.
孙锐
煤矿灾害防控全国重点实验室,重庆 400037||中煤科工集团重庆研究院有限公司,重庆 400037
矿业与冶金
近距离煤层夹矸影响应力集中动态开挖模拟非对称分布
close-distance coal seamgangue intercalation effectstress concentrationdynamic excava-tion simulationasymmetric distribution
《西安科技大学学报》 2026 (2)
354-364,11
国家自然科学基金项目(52274150)天地科技股份有限公司科技创新创业资金专项项目(2023-2-TD-ZD001)
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