大采高液压支架结构优化设计及适应性分析

针对大采高工作面动载矿压显现、煤壁易片帮等问题,基于红柳林煤矿7.0 m大采高开采实践,建立了大采高工作面顶板岩层断裂的"悬臂梁+砌体梁"结构模型及支架与围岩的简化动力学模型,确定了7.0 m大采高液压支架合理工作阻力;对比分析了大采高液压支架架型、护帮结构对围岩的适应性,进行了大采高液压支架结构优化设计及适应性分析。研究结果表明:将大采高工作面"砌体梁"结构上方岩层作为动力学模型的边界条件,以支架立柱的抗冲击特性要求为理论判据,通过动力学仿真计算可得大采高支架的合理工作阻力。两柱掩护式大采高支架较四柱支撑掩护式支架具有支护强度大、四连杆稳定机构受力状态好、质量轻等优点;护帮板与伸缩梁分体结构的护帮力、合力作用位置及可靠性均优于护帮板与伸缩梁连体结构;设计采用抗冲击双伸缩立柱、高压升柱系统等,提高了大采高液压支架对围岩的适应性。

Hydraulic support with large mining height structural optimal design and adaptability analysis

Aiming at the problems of dynamic mining pressure and rib spalling instability,the “cantilever beam and bond beam” structural model of roof strata and simplified dynamic model between hydraulic support with large mining height and surround rock were established based on the 7.0 m mining practice in Hongliulin mine.The reasonable working resistance of 7.0 m mining height hydraulic support was determined.The mechanical property and adaptability for working face surrounding rock were contrastively analyzed from the aspect of hydraulic support frame and working face guard device.Hydraulic support structures were optimally designed.The results show that the rock strata above the “voussoir beam” structure could be seen the boundary conditions for the dynamic model,and the anti impact properties requirement of hydraulic cylinder was the theoretic criterion,which could obtain the reasonable working resistance of hydraulic support through a dynamic simulation analysis.Two prop shied large mining height hydraulic support was better than four pillars from supporting intensity,four bar mechanism stress state and weight,etc.The joint system of face guard and extensible canopy had a higher face guard force,a better place of application of force and dependability than the fission system of face guard and extensible canopy.The anti impact double telescopic prop and high pressure column system were adopted to raise the adaptability of hydraulic support to surrounding rock.