时间域瞬变电磁法井下全方位赋水性探查研究

Studies on all-orientation detection of rocks' water-bearing by time domain TEM in underground mining

瞬变电磁方法对地下水反应敏感,而矿井瞬变电磁法又发挥了距离目标体近、分辨率高的特点,因此在矿井水害探查应用中具有广阔前景。采用加拿大产PROTEM-47瞬变电磁系统,通过不共面同轴偶极方式、共面偶极方式或者中心方式布置线圈实现了井下全方位探查。井下探查实践表明,矿井瞬变电磁法有效预测赋水性异常的深度(或者高度,或超前距离)可以达到110 m,与岩层电性特征、完整程度、含水性等因素有关;钻探验证表明,地质解释具有相当高的准确性。

Transient Electro-Magnetic （TEM） method is sensitivity to water-bearing in rocks. Underground TEM has characteristics of near target body, high differentiate rate, so, it has wide foreground for applying in detection of mining water disasters. All-orientation detection in underground mines can be implemented by uncoplanarity coaxial off-set loops, coplanarity coaxial off-set loops, or central loops in PROTEM-47 system made in Canada. Detecting practice in underground mines show that effective detecting depth on exceptional water-bearing bodies has relation with factors, such as electric character, intact extent, water-bearing of rock masses. Maximum depth can be 110m. Drillings validate that geological explanation has high veracity.