纳米瞬变电磁法在探测浅层铁矿采空区的实验研究

The detection of mined-out area of shallow iron ore by nanometer transient electromagnetic method

对采空区目前深部探测研究得较多,对浅部则较少,国内外对利用瞬变电磁法探测铁矿采空区应用甚少,纳米瞬变电磁法则没有涉及,在利用探地雷达和常规瞬变电磁对地表存在低阻盖层屏蔽的沉积变质铁矿浅层采空区无法取得成效时,作者利用纳米瞬变电磁(NanoTEM)在实验区进行实验,取得了良好探测效果并分析了采样周期和观测时窗对探测效果的影响.实验研究表明,在岚县浅层铁矿采空区探测中,运用中心回线模式的NanoTEM,采用小线框+小电流+合理的采样间隔+浅层采样时窗的方法,最终达到对沉积变质铁矿浅层采空区的精确探测.

At present, the research about the Mined-out area detecting more on the depth than shallow, a little engineer project was reported on the use of Transient electro-magnetic method（TEM） exporting Mine＆out area of iron ore at home and aboard, so far, nanometer transient electromagnetic method（NanoTEM） has not applied. In order to investigate the shallow Mined-out area of iron ore of Sedimentary metamorphic iron ore that the surface was covered by the low resistance can not detect by Ground Penetrating Radar and TEM, the experiment achieved good results by NanoTEM, at the same time the author analyze the effect of the sampling cycle and the observing window, the experimental indicate that applying central-loop NanoTEM small frame ＋ small current ＋ relative sampling interval ＋ shallow sampling detecting technology could reach the accurate detection of the worked-out section of shallow Sedimentary metamorphic iron ore in Lanxian.