井下瞬变电磁仪硬件对致灾水体分辨能力的评估

井下瞬变电磁随掘探测技术是探测掘进面前方致灾水体的有效方法,从硬件方面评估仪器对致灾水体的分辨能力,是仪器能够在井下正确使用的重要手段.通过比较二次场绝对差和仪器分辨率、叠加后背景噪声之间的大小关系,分析含水致灾体识别的硬件条件和评估依据;提出从硬件方面评估井下瞬变电磁对致灾水体分辨能力的计算方法:根据致灾水体结构建立...

Evaluation on the resolution ability of underground transient electromagnetic instrument to disaster-causing water bodies

The downhole transient electromagnetic detection technology is an effective method to detect the disaster-causing water body in front of the tunneling. It is an important means to evaluate the instrument's resolution ability to disaster-causing water from the aspect of hardware for the instrument to be used correctly in underground mines. By comparing the magnitude relationship between the absolute difference of the secondary field, the resolution of the instrument and the background noise after superposition, the hardware conditions and evaluation basis for distinguishing the water-bearing hazards are analyzed. A calculation method for evaluating the resolution ability of underground transient electromagnetic to disaster-causing water body from the aspect of hardware is put forward. A three-dimensional geological model is established based on the structure of the disaster-causing water body, and the relationship between the trapezoidal wave turn-off and the negative step wave turn-off secondary field induced voltage was deduced, and the full-space three-dimensional finite difference parallel was adopted on the GPU. The algorithm calculates the secondary field response of the disaster-causing water body. The turn-off time and background noise of a transient electromagnetic instrument are measured. According to the hardware discrimination basis of the disaster-causing water body, the ability of the underground transient electromagnetic instrument to distinguish water-conducting subsidence column and water-filled goaf was evaluated from the hardware aspect. The development of downhole transient electromagnetic detection instruments and accurate on-site detection provide technical reference, which is of great research significance.