摘要:
过去在煤矿浅层高阻采空区探测中,普遍认为高密度电法为较好的方法,而瞬变电磁法通常被认为其对低阻反映较灵敏,对高阻反映不灵敏,而很少采用,但我国内蒙、山西等地,地表沟壑纵横,高差较大,不具备高密度电法的施工条件。因此,笔者给出一种在较小线框下进行的瞬变电磁方法,通过配合高发射频率和大发射电流,能够比较清晰的反映出地下高阻目标体,以此说明,针对地形起伏较大,不适合高密度电法施工的地方,小框瞬变电磁方法可以在一定程度上解决煤矿中不含水采空区的物探手段问题。文中参考煤矿不含水采空区埋深较浅的情况,设计了理论模型,正演计算得到的效果良好,对高阻的反映较为灵敏,并在鄂尔多斯地区某煤矿实际应用了该方法,得到的结果与开挖情况相符合,对煤矿生产起到了很好的指导作用,这表明该方法是切实有效的。
Abstract:
In detecting goaf of coal mine with high-resistivity and shallow-layer,the commonly used method is the high density resistivity method while is TEM is considered to be sensitive for low-resistivity and insensitive for high-resistivity.So the TEM is rarely used.But for Inner mongolia and Shanxi,gullies are well developed on surface,which means that these area do not have the conditions suitable for high density resistivity method.We propose a TEM working method with small coils,high frequency,and great current,which can clearly reflect high-resistivity objective underg round.For those area with changeable land form,the high density resistivity method is unsuitable while the small coil TEM can solve the problem,to a certain degree,of physical detecting in goaf without water.This paper gives a very applicable TEM method for objective,especially for goaf without water and with a shallow buried depth.The calculation of theor etical model is in agrement with actual situation,showing that this method is practical and effective.
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