In longwall top-coal caving (LTCC) mining, progressive failure process of top coal is closely related to the mining-induced stress. In order to achieve failure mechanisms of the top coal, stress distribution of the LTCC face adjacent to the gob is analysed in this study with field investigation and numerical simulation. The concentration and rotation phenomenon of the principal stress are recognised. Particular emphasis is placed on rotation characteristics of the principal stress in the top coal adjacent to the gob. In addition, the influence provided by periodic rupture of the main roof on the mining-induced stress is discussed.

中文翻译：

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沿空采空区长壁综放工作面应力分析

在长壁放顶煤开采中，顶煤的渐进破坏过程与开采引起的应力密切相关。为了获得顶煤的破坏机理，本文通过现场调查和数值模拟分析了与采空区相邻的LTCC工作面的应力分布。识别出主应力的集中和旋转现象。特别强调与采空区相邻的顶部煤中主应力的旋转特性。此外，还讨论了主顶板周期性破裂对采矿诱发应力的影响。