通过物理模型实验,研究矿井富水异常体的瞬变电磁场响应特征,为改进资料解释方法、提高探测精度提供重要依据。根据物理模型实验相似性准则,设计物理模型参数并校正模型系数;制作矿井富水体物理模型及发射接收装置,并对天线参数及探测能力进行对比分析。实验结果表明:在发射天线参数相同的条件下,接收天线绕制匝数越多,接收到的感应信号就越强;发射线圈中的电流越大,接收到的信号越强;相同条件下,方形天线装置比圆形天线装置接收到的感应信号强。巷道空间及空间内的金属体对富水体感应场的干扰特征实验表明:当天线位于巷道靠近富水体所在一侧时,接收到的响应值最高;当天线位于远离富水体一侧时,由于巷道空间的影响使探测结果的分辨能力降低。巷道内的金属体(工字钢、金属锚网和铁轨)使所接收到的信号值变大,而富水异常体的响应规律则没有变化。
By using the physical model experiment, the transient electromagnetic response character of mine water-bearing structure is studied, which provides an important basis for the improving interpretive method and advancing accuracy of detecting mine water-bearing structure. According to the similarity criterion of the physical model, the specific parameters of physical model and the corresponding correction factors are calculated. In addition, the mine water-bearing structure model and the transmitting and receiving devices are constructed; and the antenna parameters and detection abilities are comparatively analyzed. The results indicate that for the same transmitting antenna parameters, the more the turns of receiving antenna are, the stronger the received signal is; the larger the current in transmitting coil is, the stronger the received signal is. Under the same conditions, the inductive signal from the square antenna device is stronger than that of circular antenna. The physical model experiments are performed for interference characteristics of induction field from laneway space and metal body within laneway space. The results indicate when antenna lies near the side of the water-bearing structure, the received response value is the maximum. When the antenna lies away from the side of the water-bearing structure, the detecting ability is lower because of the influence of laneway space; the response values become strong for the metal(H-iron, metal netting and rail) in laneway space, but the response law of water-bearing structure is not affected.