松软煤层简放开采的矿压特征与适应性研究

为了给简易放顶煤开采技术提供理论依据，采用现场实测和数值模拟的方法对简放开采的矿压显现规律、支架围岩关系及其适应性进行了研究．放煤对支护系统稳定性的影响主要体现在末排支柱稳定性的变化，放煤导致末排支柱的工作阻力下降1／2左右．简放工作面顶板控制中，“支”和“稳”对提高支护系统的稳定性作用是有限的，关键在于“护”．简放开采支护系统要具有良好的水平约束必须要求一定厚度的直接顶、较小的煤矸破碎块度、低位放煤、控制放煤口尺寸和放煤速度．理论分析与实践效果表明，简放开采技术应用于软直接顶的松软厚煤层具有良好的适应性．

Strata Behaviors and Adaptability of Drawing Top-Coal with Hydraulic Props for Soft Coal Seams

In order to offer theoretical basis for the technology of drawing top-coal with hydraulic props,strata behaviors rule,relationship between support and surrounding rock,and adaptability of drawing top-coal with hydraulic prop in soft thick coal seam were studied by in-situ observation and numerical simulation.Drawing top-coal affects the stability of support system,especially the stability of the end row hydraulic prop.The working resistance of the end row hydraulic prop will decline about half induced by drawing topcoal.The function of "support" and "steady" in enhancing the stability of support system is limited in drawing top-coal.The key of roof control of caving top-coal working face with hydraulic props is "shielding".Good horizontal constraints for support system of drawing top-coal with hydraulic props require that the immediate roof should be thick enough,the fragment dimension of topcoal and refuse should be small,the position of caving top-coal jaws should be low,and the size of drawing top-coal jaws and drawing top-coal velocity need to be controlled.Theoretical analysis and practical effect show that the technology of drawing top-coal with hydraulic props is well suitable for soft coal seams and soft immediate roofs.