The advance speed of a longwall face is an essential factor affecting the mining pressure and overburden movement, and an effective approach for choosing a reasonable advance speed to realise coal mine safety and efficient production is needed. To clarify the influence of advance speed on the overburden movement law of a fully mechanised longwall face, a time-space subsidence model of overburden movement is established by the continuous medium analysis method. The movement law of overburden in terms of the advance speed is obtained, and mining stress characteristics at different advance speeds are reasonably explained. The theoretical results of this model are further verified by a physical simulation experiment. The results support the following conclusions. (i) With increasing advance speed of the longwall face, the first (periodic) rupture interval of the main roof and the key stratum increase, while the subsidence of the roof, the fracture angle and the rotation angle of the roof decrease. (ii) With increasing advance speed, the roof displacement range decreases gradually, and the influence range of the advance speed on the roof subsidence is 75 m behind the longwall face. (iii) An increase in the advance speed of the longwall face from 4.89 to 15.23 m/d (daily advancing of the longwall face) results in a 3.28% increase in the impact load caused by the sliding instability of the fractured rock of the main roof and a 5.79% decrease in the additional load caused by the rotation of the main roof, ultimately resulting in a 9.63% increase in the average dynamic load coefficient of the support. The roof subsidence model based on advance speed is proposed to provide theoretical support for rational mining design and mining-pressure-control early warning for a fully mechanised longwall face.

中文翻译：

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推进速度对长壁采煤覆岩运动特性的影响：理论分析与物理模拟的启示

长壁工作面的推进速度是影响采煤压力和覆岩运动的重要因素，需要找到合理的推进速度来实现煤矿安全高效生产的有效途径。为阐明推进速度对综采工作面覆岩运动规律的影响，采用连续介质分析法建立了覆岩运动时空沉降模型。得到了上覆岩层随推进速度的运动规律，合理解释了不同推进速度下的开采应力特性。通过物理仿真实验进一步验证了该模型的理论结果。结果支持以下结论。(i) 随着长壁工作面推进速度的增加，主顶板和关键地层的第一次（周期）破裂间隔增加，顶板沉降、破裂角和顶板旋转角减小。(ii) 随着推进速度的增加，顶板位移范围逐渐减小，推进速度对顶板沉降的影响范围为长壁工作面后75 m。(iii) 长壁工作面推进速度从 4.89 提高到 15.23 m/d（长壁工作面每日推进），导致主干裂隙岩石滑动失稳引起的冲击载荷增加 3.28%屋顶和主屋顶旋转引起的附加荷载减少 5.79%，最终导致支座的平均动荷载系数增加 9.63%。