电阻率法测试煤体中水分运移距离的可行性探析

Feasibility of measuring water transport distance in coal by resistivity method

为了定量测试水分在煤体内的运移距离,开发了电阻率测试技术并探讨了其可行性。研究结果表明:采用分层布置电极的方法与显色指示剂法所测试的水分运移距离均随时间的增加而增加;随着时间的增加,煤样电阻率的变化分为突变过程、快变过程、渐变过程,电阻率法与显色指示剂法所测试的运移距离基本一致,相对误差在-4.2%~5.8%之间;可采用布置梳状电极、布置分层电极、一端竖向打孔布置测试电极的方法分别对无加载围压柱状样品、加载轴压/周围被约束样品及加载轴压/围压样品进行运移距离测试。

To quantitatively test the migration distance of water in coal,this paper develops the resistivity measurement technology and discusses its feasibility.The results show that the water transport distance measured by layered electrode arrangement method and color indicator method increase with the increase of time.With the increase of migration time,the change of coal sample resistivity can be divided into three change processes,which are sudden change process,rapid change process and gradual change process.The migration distance measured by resistivity method and color indicator method are basically the same,and the relative error is between-4.2%and 5.8%.The methods of arranging comb electrodes,arranging layered electrodes and arranging test electrodes with vertical holes at one end can be used to test the migration distance of unloaded confining pressure cylindrical samples,loaded axial pressure/surrounding constrained samples and loaded axial pressure/confining pressure samples,respectively.