低压联合注水预防井筒破坏工业试验

Industrial test on prevention of mine-shaft failure using low-pressure water injection

针对高压注水停止后井壁应力弹性急升、井壁应变大于注水前应变的问题,以济三煤矿风井为例,通过理论分析,对Z5、Z6孔低压联合注水工业试验,探索了两孔低压联合注水的可行性,并对注水前后Q_下-1、Q_下-3、Q_下-4和Z1孔的水位变化、注水段冲积地层应变状态和井筒井壁应变状态进行了分析。结果表明:Q_下-3、Z1孔水位升高明显,升高幅度分别为3.67 m、4.16 m,Q_下-1、Q_下-4孔水位升高幅度相对较小,为1.03 m、1.77 m,注水结束后,各孔水位下降明显;冲积地层第24、29、32、34层应变与对应Z1孔水位升降具有同步性,第38层应变与对应Q_下-3孔水位变化没有同步性,这与该地层处于冲积层与基岩交界面附近有关;注水对风井井壁垂直应变影响明显,Q_下-3孔水位每抬升1 m,对应风井172 m水平52V-1、53V-1的垂直微应变平均增大15.40和15.23;风井172 m水平垂直应变量与对应Q_下-3孔水位变化量呈线性相关,可为简单判断井壁受力状态提供依据。

Due to the problem of stress elastic rapid rise of the borehole wall and strain of borehole wall increase when high pressure water injection was stopped,the ventilation shaft of Jining No.3 coal mine was taken as example,through theoretical analysis,industrial experimental of Z5,Z6 hole water injection combined with low pressure,to explore the feasibility of the two hole joint injection,and water level variation with time of the water level observation hole,strain state of alluvial strata and shaft wall strain before and after water injection were analyzed.The results show that Q_(under)-3,Z1 hole water level increased significantly by 3.67 m and 4.16 m;Q_(under)-1、Q_(under)-4 hole water level rise was relatively small by 1.03 m and 1.77 m.After injection,the water level decreased significantly;24th,29th,32nd,34th alluvial strata strain and corresponding Z1 hole water level fluctuation were synchronous,and 38th strata strain and corresponding Q_(under)-3 hole water level variation without synchronization was related to strata in the vicinity of alluvium and bedrock related interface;Water injection had a significant effect on ventilation shaft vertical Strain,Q_(under)-3 hole water level each uplift 1m,the vertical microstrain of the corresponding shaft 172 m level 52V-1,53V-1 average increased 1.54 and 15.23;Ventilation shaft 172 m level vertical strain variables and the corresponding Q_(under)-3 hole water level variation was linear correlation,could provide a basis for simple judgment shaft wall strain state.