放顶煤开采支架工作阻力的确定

DETERMINATION OF WORKING RESISTANCE OF SUPPORTSFOR SUB LEVEL CAVING MINING

通过分析放顶煤开采围岩系统的运动特征，认为顶煤体在支架－围岩系统中起着关键性作用，提出了定量描述顶煤体物理力学特性变化的原理与方法．研究认为，支架承受上覆岩层的外载等于促使顶煤体在垂直方向变形的压力，并给出了定量的计算公式，据此公式成功地解释了放顶煤开采顶煤体愈软。

Based on the characteristics of movement of rock system in sub level caving, it is considered that the mass of the top coal plays a critical role in the system of support and rock. Variation of mechanical properties of the top coal is described quantitatively. It is held that the external load of the overlying rocks on the supports is equal to the pressure which causes the vertical deformation of the top coal. And a formula for quantitative analysis is proposed. It explains why the softer the top coal solid, the less is the load on the supports, and that the load on the supports is not in direct proportion to the mining height.