长壁充填开采充填体稳定性研究

Stability of backfill in long wall filling mining

为了研究长壁充填开采初凝充填体在采空区中的稳定性,按照初凝充填体呈现塑性区和弹性区共同承载的受力特性,采用威尔逊约束理论和SMP应力屈服准则,推导得出了充填体保持稳定所需的最小柱体宽度的理论计算公式,分析了充填体稳定宽度的影响因素。通过榆阳煤矿充填开采实例,实验测得充填体凝固试块的力学强度及其与时间之间的数学关系式,采用理论推导公式计算得到了充填体稳定最小宽度为3.5m。在理论计算值的基础上适当增加充填体宽度,既可增加充填体的整体稳定性,保证充填开采控制覆岩破坏的效果,又能有效减少充填体多次充填的凝固等待时间,提高开采充填效率。

To study the stability of initial coagulation backfill in the goaf for longwall mining filling, according to the loading stress characteristics of the initial condensate filling body jointly loaded in the plastic zone and elastic zone, the theoretical calculation formula of the backfill minimum width needed to keep the filling stable has been derived, and the influence factors of the width of the filling body’s stability have been analyzed through Wilson constraint theory and SMP stress yield criterion. Based on the practical case of Yuyang coal mine filling mining, mechanical strength of backfill block of solidification and the mathematical relationship between the time and the strength have been measured in the experiment, and minimum width of the backfill, 3.5 m, has been figured out by the theoretical formula. It is believed that on the basis of the theoretical calculation value, proper increase of backfill width can both enhance the overall stability filling, guarantee controlling overlying rock movement, and effectively reduce the waiting time of solidification during many filling times, improving the efficiency.