【摘要】 受沉积环境影响，风氧化带煤层及覆岩呈现裂隙发育、自稳能力差的特点，导致巷道与工作面顶板管理困难。本文分析了风氧化带煤岩体的破坏特性，并结合模型试验及数值模拟手段，研究了综放工作面覆岩的应力分布状态、变形破坏特征及运移破断规律。结果表明：(1)风氧化作用导致煤岩体强度衰减，塑性变形增大；(2)在采动影响下，覆岩应力自原岩应力状态释放并显著降低，在工作面煤壁前方及端头形成应力集中区；(3)在回采过程中，裂隙自煤壁向上发展引发煤壁片帮与顶煤垮落，形成组合悬臂梁及铰接岩梁结构，覆岩依次经历“离层发育、直接顶破断、间接顶破断和高位岩层垮落”四个变形破坏阶段。研究成果可为风氧化带煤层综放工作面的安全开采提供理论依据。更多还原

【Abstract】 Affected by the depositional environment, coal seams in the weathered and oxidized zone and their overlying strata are characterized by developed fractures and poor self-stability, leading to difficulties in roadway and working face roof management. This paper analyzes the failure characteristics of coal-rock masses in this zone. Combined with model tests and numerical simulation methods, it investigates the stress distribution status, deformation-failure characteristics, and movement-fracture laws of the overlying strata in a fully mechanized top-coal caving working face. The results indicate:(1) Weathering and oxidation significantly degrade strength and increase plastic deformation in coal-rock masses;(2) Under mining-induced disturbance, overlying strata stress is released from the in-situ state and sharply reduced, forming stress concentration zones ahead of the coal wall and at face ends;(3) During mining, fractures propagating upwards from the coal wall trigger rib spalling and top-coal collapse, forming combined cantilever and articulated rock beam structures. The overlying strata sequentially undergo four deformation-failure stages: "bed separation, immediate roof fracture, main roof fracture, and high-level strata collapse". The research findings can provide a basis for the safe mining of fully mechanized top-coal caving faces in weathered and oxidized coal.更多还原