电磁精细探测法在隐伏型导水地质裂缝勘探中的应用

针对传统隐伏型导水地质裂缝勘探方法存在勘测精度较差的问题,提出电磁精细探测法探析隐伏型导水地质裂缝。依照屏蔽系数、实测场强和理论场强数据绘制综合曲线图,通过该图获取隐伏型导水地质裂缝所处位置几何阴影范围,采用层析成像法得到网格化的工作面,获取隐伏型导水地质图像。通过图像直接观测隐伏型导水地质工作面裂缝所处位置,在此基础上,观测四个电磁场分量,采用正交电磁场分量计算介质视电阻率,依据计算视电阻率数值和视电阻率分布状态研究裂缝发育情况和裂缝富水程度。结果表明:采用该方法能较为精准地获取隐伏型导水地质裂缝位置。通过裂缝位置进一步检测出隐伏型导水地质裂缝最大发育高度为63.5 m。当视电阻数值不断增加时,隐伏型导水地质裂缝和裂缝富水性逐渐减小,与实际情况较为相符,说明该种方法探析效果较好。

Application of electromagnetic fine detection method to exploration of concealed water-conducting geological fissure

Aiming at the problem of poor exploration accuracy of the conventional method of exploring the concealed water-conducting geological fissure，it is proposed herein to explore the concealed water-conducting geological fissure by means of electromagnetic fine detection method． A comprehensive curve diagram is made in accordance with shielding coefficient，measured intensity and theoretical field intensity data，from which the geometric shadow of the location of the concealed water-conducting geological fissure is obtained，and then the gridding working face is got through tomography for obtaining the concealed water-conducting geological image． Through the image，the location of the fissure in the concealed water-conducting geological working face is directly observed． On the basis of this，four electromagnetic field components are observed and the apparent resistivity of medium is calculated with the orthogonal electromagnetic field component，while the development of the watery degree of the fissure are calculated according to the numerical value of the calculated apparent resistivity and the apparent resistivity distribution status． The result shows that the location of the concealed water-conducting geological fissure can be more accurately obtained． The maximum development height of the concealed water-conducting geological fissure is further detected to be 63. 5 m through the location of the fissure． When the numerical value of the resistivity is continuously increased，both the concealed water-conducting geological fissure and the watery yield property of the fissure are gradually decreased，which is consistent with the actual state，thus it is demonstrated that the detecting effect of this method is better．