中厚煤层综采面切顶沿空留巷围岩控制技术研究

Surrounding Rock Control Technology of Roof-cutting Gob Side Entry Retaining of Fully-mechanized Mining Face in Medium-thick Coal Seams

采掘接替紧张是制约煤矿高质高效开采的重要问题之一,同时,巷道围岩变形控制难度随着煤矿开采深度的增加而不断提升。将九里山矿东二工作面作为研究对象,通过采用理论分析、现场试验等方式,重点分析了沿空留巷情况下上覆岩层运动变形情况,并结合工作面地质条件,提出了围岩控制技术要点。通过研究得到,在对东二工作面巷道进行沿空留巷时,可采用顶板补强支护、挡矸防护、滞后支护、采空区侧强制切顶卸压等方式,对巷道围岩进行强化控制。从现场实践来看,采取复合型稳定控制措施后,顶板最大下沉量和底板最大鼓起量均在100 mm左右,实体煤帮的最大移近量在130 mm左右,采空区侧煤帮的最大移近量在100 mm左右。巷道变形量均处于合理范围内,取得了较好的留巷效果,对类似情况下选择应用沿空留巷技术有一定的借鉴意义。

The tension of mining and excavation replacement is one of the important problems restricting the high-quality and efficient mining of coal mines.Meanwhile,the difficulty of deformation control of roadway surrounding rock is increasing with the increase of mining depth.Taking the East No.2 working face of Jiulishan Coal Mine as the research object,through theoretical analysis and field test,the motion deformation of overlying strata under the condition of gob side entry retaining was analyzed,and combining with the geological conditions of working face,the key technical points of surrounding rock control were put forward.According to the study,when conducting gob side entry retaining in the roadway of the East No.2 working face,roof strengthening support,gangue retaining protection,hysteretic support,goaf side forced roof cutting pressure relief and other methods can be adopted to strengthen the control of roadway surrounding rock.From the field practice,after taking compound stability control measures,the maximum subsidence of the roof and the maximum bulking of the floor were about 100 mm,the maximum approaching amount of the solid coal wall was about 130 mm,and the maximum approaching amount of the coal wall at the goaf side was about 100 mm.The deformation of roadway was within a reasonable range,and a good roadway retention effect was obtained,which has certain reference significance for selecting gob side entry retaining technology under similar circumstances.