浅埋特厚煤层小窑采空区瞬变电磁探测技术研究及应用  

Research and application of TEM detection technology for small mine gob area in shallowly-buried and extremely thick seam

作　　者：姜志海[1,2] 杨光[3] 

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [3]江苏省地质勘查技术院,江苏南京210049

出　　处：《采矿与安全工程学报》2014年第5期769-774,共6页Journal of Mining & Safety Engineering

基　　金：国家重点基础研究发展计划(973)项目(2013CB227900);国家自然科学基金青年基金项目(41304113)

摘　　要：根据海拉尔露天矿区实际地质情况建立相应的地球物理模型,对理论地电模型和高阻采空区模型进行三维数值模拟,探讨高阻目标体的瞬变电磁响应特征和分布规律,并确定适合该地区的时深换算系数。结果表明：瞬变电磁法能够比较清晰地反映出地下浅埋高阻目标体,视电阻率等值线横向变化剧烈,受其影响,视电阻率等值线上拱或下凹,形成明显的高阻异常区,与物理模拟实验结论相似,时深换算系数取1.1～1.2时计算得到的视深度与实际地层厚度的误差较小。工程实践表明：对于埋深不大于100 m的小窑采空区而言,只要选择合理的参数,瞬变电磁法能够探测出直径大于5 m的未塌陷小窑采空区,并可查明其空间分布范围和埋深。Three-dimensional numerical simulation has been carried out to test the theoretical models and high-resistance gob area models in coal mine based on the geophysical model established according to the actual geological conditions of the opencast mine in Hailaer. The response characteristic and dis-tribution law of transient electromagnetic field have been discussed and the parameter of time-depth conversion has been determined. The numerical results show that Transient electromagnetic method can clearly reflect the shallowly-buried and extremely thick high-resistance objective underground. The lev-el curve of the apparent resistivity has a drastic lateral variation, with a camber and concave line, which indicates that it is the high resistivity anomaly area. And numerical method has similar conclusions with physical experiment for the geologic model. For a given geoelectric model when choosing time-depth conversion parameter γ=1.1 or 1.2, the error is small. The applied result shows that： for the inter-mining coal pit, with the buried depth less than 100 meters, as long as a reasonable parameter is chosen, TEM can find out the small mine gob area with over 5 meters in diameter and its distribution range and depth.

关 键 词：小窑采空区 瞬变电磁法 数值计算 时深转换 

分 类 号：P631[天文地球—地质矿产勘探]