锚网支护对矿井瞬变电磁响应的影响与校正

Influence of Bolt-net Support on Mine Transient Electromagnetic Response and Its Correction

巷道中锚网支护对矿井瞬变电磁探测结果影响较大。为研究施工过程中锚网造成的干扰响应机制,基于COMSOL软件模拟锚网支护下不同探测距离时矿井瞬变电磁响应特征,分析其影响规律;结合相关井下试验,研究不同探测方向时锚网对矿井瞬变电磁的干扰特征;对某矿井下受锚杆支护干扰的瞬变电磁原始数据采用多项式拟合函数进行校正处理。研究表明:锚网支护使瞬变电磁接受的二次场感应电动势显著偏大,锚网干扰程度在一定范围内与线框的距离反相关,且探测线框平面正对金属体时受到的干扰响应最大。采用的校正方法很好地还原了真实电阻率分布特征,提高了解释精度。

The bolt-net supporting in the roadway has a great influence on the results of the mine transient electromagnetic detection.To study the interference response mechanism caused by the bolt-net supporting during construction,the mine transient electromagnetic response characteristics at different detection distances under the bolt-net supporting were simulated based on COMSOL software,and the influence laws were analyzed.Combined with the relevant downhole test,the interference characteristics of bolt-net supporting to mine transient electromagnetic in different detection directions were studied.Finally,the original data of mine transient electromagnetic under mine was corrected by the polynomial fitting function.The research showed that the accepted secondary induction potential value increased obviously under the influence of the bolt-net supporting,and the influence degree of interference was inversely related to the distance of the wire frame with a certain range,and the interference response is the greatest when the detection wire frame plane is positive to the metal body.The correction method can well restore the true resistivity distribution characteristics and improve the interpretation accuracy.