柠条塔煤矿大采高工作面切顶沿空留巷围岩变形机理研究

以柠条塔煤矿大采高工作面预裂切顶沿空留巷为工程背景,采用有限元数值模拟方法分析预裂切顶对沿空留巷围岩应力分布的影响。介绍了沿空留巷支护和爆破施工参数,根据围岩表面位移、顶板离层、恒阻锚索受力、液压支架工作阻力监测数据,分析了从开始留巷到变形稳定矿压显现规律。现场试验表明:切顶卸压自动成巷技术能够切断采动应力传递路径,明显降低了浅埋大采高工作面沿空留巷围岩受到的动压扰动,有效抑制了巷道围岩变形,成巷断面尺寸满足生产要求。

Research on Rock Deformation Mechanism of Gob-side Entry Retaining Formed by Roof Cut in Large Mining Height Working Face

With the engineering background of gob-side entry retaining of large mining height working surface in Ningtiaota Coal Mine by roof pre-splitting,the finite element method were used to analyze the influence of roof pre-splitting to the stress distribution of surrounding rock during gob-side entry retaining.The of gob-side entry retaining supporting and blasting construction are introduced.According to the monitoring data of displacement and separation of surrounding rock,roof separation,the stress of the constant resistance anchorage cable,work resistance of hydraulic support,the appearance law of surrounding rock pressure from the beginning,deformation,stabilizing the pressure is analyzed.Field test shows that the entry retaining formed by roof cut and pressure releasing technique can cut off the transfer path of mining stress,significantly reduce the dynamic pressure disturbance on the gob-side entry retaining surrounding rock at shallow buried and large mining height working surface,and effectively restrain the deformation of surrounding rock.The roadway section size can meet the requirements of production.