工作面覆岩破坏双孔并行电法数据多方法处理

Multi-method Processing and Interpretation of Monitoring data of Double Hole Parallel Electrical Method for Overburden Damage in Coal Face

掌握垮落带和导水裂隙带发育高度对于煤矿工作面安全开采具有重要的意义.通过在煤层工作面布置覆岩破坏双孔电法监测系统,采用并行电法仪AM法方式,采集覆岩破坏电性变化数据,通过单孔电极电流比值、双钻孔电极电流比值、单钻孔高密度电阻率法和双钻孔电阻率反演成像等多种处理方法,综合解释覆岩破坏发育规律.实例研究表明:单钻孔电极电流比值变化图可以直观地反映各电极点电流比值随推进时间及回采位置的动态变化,分析各电极点位置变形与破坏情况;双钻孔电极电流比值图,能够清晰反映出某个采集时间的覆岩破坏带的空间位置;单钻孔高密度电阻率法能够反映钻孔周边岩层视电阻率的动态变化情况,分析在钻孔附近的岩层破坏情况;双钻孔电阻率反演成像,可以反映钻孔控制空间垮落带及裂隙带发育形态.通过多方法处理综合解释,能够充分发挥并行电法多参数数据优势,弥补单方法处理与解释的缺点,更全面地反映采后垮落带及裂缝带发育的动态变化过程,更好地指导工作面安全开采工作.

It is very important to master the development height of caving zone and Water-conducting fissure zone for safe mining.By arranging the double hole electrical monitoring system for overburden damage in the coal working face and adopting the AM method of parallel electrical instrument,the electrical changes data of overburden damage are collected.The development law of overburden damage is comprehensively explained by the methods of single hole electrode current ratio,double hole electrode current ratio,single hole high-density resistivity and double hole resistivity inversion imaging.The study shows that the current ratio diagram of single borehole electrodes is able to reflect directly the dynamic change of current ratio of each electrode point with advancing time and mining position,analyzing the deformation and damage of each electrode point,the current ratio diagram of double borehole electrodes reflect clearly the spatial position of the failure zone at an data-collecting time,the single borehole high-density resistivity method reflect the dynamic change of apparent resistivity of rock around the borehole,analyzing the damage of rock near the borehole,and the inversion resistivity imaging of dual boreholes reflect the development shape of the collapse zone and fracture zone.Through multi method processing and comprehensive interpretation,it will give full play to the advantages of multi parameter data of parallel electrical method,make up for the shortcomings of single method processing and interpretation,more comprehensively reflect the dynamic change process of post mining caving zone and fracture zone development,and better guide the safe mining work of the working face.