等值反磁通瞬变电磁法在煤田采空区探测中的应用

The Application of Opposing Coils Transient Electromagneticin Mined-out Area Detection in Coalfield

煤田老窑采空区是煤矿安全生产的主要隐蔽致灾因素,瞬变电磁法具有成本低、效率高,且对低阻体敏感等特点,是煤矿采空区探测的常用方法。本文以新疆沙湾县小沟煤矿为研究对象,进行了中心回线装置和等值反磁通装置对比试验,最终采用等值反磁通瞬变电磁与工程地质钻探相结合的方法,基于已知采掘巷道充水的异常特征及钻探验证信息,建立了低阻异常识别标志,有效地圈定了煤田采空区。结果表明,在煤田采空区充水且埋深小于200 m的情况下,等值反磁通装置得到的异常幅度要比中心回线装置高3~5倍,对低阻异常体的灵敏度更高,发现异常的能力更强。应用等值反磁通瞬变电磁法可以查明采空区形态、厚度、埋深等特征,适用于干扰严重、地形复杂、建筑密集的矿山复杂环境。

Goaf in old kilns is the main hidden disaster factor in coal mine safety production.Transient electromagnetic method is a common method for goaf detection in coal mines because of its low cost,high efficiency and sensitivity to low resistance bodies.This paper takes Xiaogou coal mine in Shawan county,Xinjiang autonomous region as the research object,carries out a comparative test of central loop device and reverse magnetic flux device,and finally adopts the oppsing coils transicent electromagnetic(OCTEM)and engineering geological drilling.Based on the known abnormal characteristics of water filling in mining roadway and drilling verification information,the low resistance anomaly identification mark is established,and the goaf is effectively defined.The results show that when the goaf is filled with water and the buried depth is less than 200 meters,the anomaly amplitude obtained by the equivalent inverse magnetic flux device is 3~5 times higher than that of the central loop device,and the sensitivity to the abnormal body with low resistance is higher,and the ability to detect anomalies is stronger.The oppsing coils transicent electromagnetic can be used to find out the characteristics of the form,thickness and buried depth of the mined-out area,which is suitable for complex mine environment with serious interference,complex terrain and dense construction.