大采高综采破碎顶板液压支架压架致损机理分析

Analysis on the Damage Mechanism of Hydraulic Powered Supports Crushing at the Broken Roof of Fully Mechanized Mining Face with Great Cutting Height

针对大采高综采工作面破碎顶板条件下液压支架破损情况,对液压支架破损的原因进行了探讨。在已有的两柱掩护式支架受力力学模型的基础上,建立了支架耳座、掩护梁的受力模型。分析结果表明,在大采高顶板破碎条件下,平衡千斤顶受到支架位态的影响处于受拉状态,导致耳座与掩护梁焊接处开裂;掩护梁在上覆岩层产生的压应力作用下产生弯曲应力,弯曲应力最大位置处布设的管孔易产生应力集中,导致掩护梁产生裂纹并贯通。

In view of hydraulic powered supports crushing damage at the broken roof of fully mechanized mining face with great cutting height,the reasons of hydraulic powered supports damage were discussed in this paper. Based on the existing stressed model of 2-leg shield support,the force model of auris seat and shield beam was built. The anal- ysis shows the following findings：The equilibrium jack is in tension with the influence of support state under the large mining height broken roof, which leads to the cracking on the welding between ear block and shield beam; ben- ding stress is produced on the caving field when the overlying strata is under compression stress; tube holes are loca- ted where the greatest bending stress reaches the maximum value;stress concentration is produced around the pores, which leads to the initiation of cracking failure of shield beam.