不稳定厚煤层放顶煤开采煤矸流场规律的数值模拟研究

Study on Coal and Gangue Flow Rule of Top-coal Caving with Erratic Hick Coal Seam by PFC^(2D)

放顶煤开采过程中,由于顶煤厚度的变化,使得煤矸流场规律发生变化,影响了顶煤的放落回收。基于鹤壁十矿在煤层厚度变化较大条件下放顶煤开采的实际,应用PFC2D计算程序,模拟分析了顶煤厚度变化,即采放比不同对煤矸流场特征和顶煤放出规律的影响。结果表明:顶煤损失是随放煤循环逐渐积累的过程,煤矸流动的速度场和接触力场以放煤口为中心呈半拱形状,距放煤口距离越小,接触力越小。

In top coal caving,with the impact of the greatly changes in the thickness of coal seam,leading to the change of the thickness of the top coal,which has changed the caving ratios. Because of the changes in the thickness of the top coal,leading to the rule of coal and gangue flow changed,affecting the drop and recovery of top coal. Based on the situation of Hebi Shikuang,where the coal seam changed greatly and adopt the top coal caving method,apply PFC2 Dcomputational procedures,simulation and analysis the effect rule on the rule of coal and gangue flow and release of top-coal by the change of top coal thickness,which is the influence of different caving ratios. And the results are that the loss of top coal is a gradual accumulation process along of caving cycle,coal and gangue flow velocity and contact force field become half-arch shape with the exhausting-flowing remover as circle center,the smaller the distance to exhausting-flowing remover,the smaller the contact force.