矿井瞬变电磁超前探测视电阻率扩散叠加解释方法

Spread stack interpretation means of apparent resistivity in roadway advanced detection with transient electromagnetic method

受体积效应的影响,矿井巷道瞬变电磁超前探测时对异常区有不同程度的放大。为获得更为可靠的测试结果,在扇形超前观测系统的基础上,通过烟圈简化反演,并根据不同测点在巷道前方形成的烟圈交汇特征,推导视电阻率扩散叠加表达式及相关参数计算公式,实现了超前探测视电阻率扩散叠加解释方法,进一步提高对前方地质体的分辨能力。物理模型实验和现场探测实践表明,与常规视电阻率断面对比,视电阻率扩散叠加结果对异常体的判定效果优越性较强,对巷道掘进前方含水体的聚焦判定能力增加。

In advanced detection by mine transient electromagnetic method, because of the volume effect, the abnormal areas are amplified in various degree. To obtain a more reliable test results, through the smoke ring simplified inversion for the conventional apparent resistivity and according to the intersection characteristics of smoke rings formed by dif ferent survey points arranged as sector observing system in front of roadway, the spread stack expression of apparent resistivity and its related parameter were derived. So, the spread stack interpretation means of apparent resistivity was re alized in advanced detection, it further improves the resolving power of geological body ahead of tunnel. Physical model experiment and field exploration show that, the spread stack interpretation means of resistivtiy to judge the model is su perior to the conventional apparent resistivity section, it increases the judgement ability of water aquifer ahead of exca vation roadway.