房式采空区下特殊岩梁结构支架工作阻力分析

SUPPORT RESISTANCE ANALYSIS FOR SPECIAL ROOF STRUCTURES UNDER ROOM MINING GOAF

通过改进台阶岩梁结构,提出"单回转岩块"结构,并得到该结构中支架工作阻力计算公式。对神东矿区石圪台煤矿31201工作面在实体煤下、房式采空区下和过上覆房式采空区集中煤柱3种不同条件下回采时,分别提出"砌体梁–单回转岩块"、"小错位砌体梁–单回转岩块"和"严重错位砌体梁–单回转岩块"3种覆岩错位砌体梁结构,并利用单回转岩块结构的支架工作阻力计算公式得到3种覆岩错位砌体梁结构下支架合理工作阻力。结果表明:理论计算结果与现场实测数据较吻合;工作面过上覆房式采空区集中煤柱期间,无法单纯通过提高支架阻力来避免压架灾害的发生。

A single rotary rock block model with the revised step voussoir beam was proposed and a formula calculating the working resistance was established. For the roof structure of the shallow fully-mechanized face,i.e.,31201 working face of Shigetai coal mine in Shendong mining area,three different conditions according to the overlying coal seam which was the solid coal,or the room and pillar goaf or the concentrated pillar in room and pillar goaf were considered so that the roof structures were proposed as a voussoir beam-single rotary rock block,a slight dislocation voussoir beam-single rotary rock block and a severe dislocation voussoir beam-single rotary rock block respectively. The mechanical model of the single rotary rock block was used to calculate the working resistance of support under different roof conditions in Shigetai coal mine. The results showed that the working resistances calculated with the model in different roof structures were correct and the crushing accident of the support cannot be avoided by increasing the working resistance only.