基于超小线圈瞬变电磁场的巷道水害超前预报理论与方法研究

The fault water, gob water and other geological anomalies existing in front of roadway excavation may cause some disasters, such as water-inrush, thus threatening mine safety seriously.There are many limitations in water-disaster detection based on drilling and geophysical methods, such as real-time prediction. So using the transient electro-magnetism(TEM) field of ultra small coils as source, the research on theory and methods of advance prediction on water disaster has important theoretical and practical significance for mine safety.The project mainly uses the theoretical analysis, numerical calculation, physical simulation, field trials to deal with the basic scientific problems of water disaster monitoring based on the TEM field of ultra small coils, including: (1) The wave propagation characteristics of the TEM field of ultra small coils in seam and stratum under the condition of whole space and the shield theory and methods of cortex field. (2) The response characteristics of the vortex field of ultra small coils caused by different aquifer structures with different water contents in front of roadway and the methods of information identification and automatic interpretation of different aquifer structures and their contents. (3) The high-resolution resistivity imaging method of the TEM field of ultra small coils, the methods of noise suppressing and its correction.(4) The method of directional detection and advance prediction on water disaster based on the TEM field of ultra small coils. Solving these problems couldimprove the efficiency and precision in detecting aquifer structures in front of roadway.And then the basis in theory and application for advance prediction on water disaster is established.

掘进巷道前方存在的断层水、老空水等灾害性含水体是矿井突水灾害的主要隐患，传统的以钻探和物探为主的探查水源方法存在着诸多局限性，不能实时预报，因此，进行以超小线圈瞬变电磁场为场源的水害超前预报理论与方法研究，对于矿井水害防治具有重要的理论意义和应用价值。项目主要采用理论分析、数值计算、物理模拟、现场试验等多途径、多方法，对超小线圈瞬变电磁场监测水害相关基础科学问题进行系统研究，主要包括：（1）全空间条件下超小线圈的瞬变电磁场在煤层和岩层中的传播特征，涡流场屏蔽理论与方法；（2）巷道前方不同含水体及不同含水量的超小线圈涡流场响应特征，不同含水体及含水量的信息识别和自动解译方法。（3）超小线圈瞬变电磁场的高分辨率电阻率成像方法，噪声压制及校正方法；（4）超小线圈瞬变电磁指向性观测方法和水害超前预报方法。解决上述问题，实现对巷道前方含水体的高效、精细监测和定位，为水害超前预报奠定理论和应用基础。

矿山掘进巷道前方水害超前实时预报的难点是巷道前方的灾害性水体是隐蔽的，看不见闻不着，传统的以钻探和地球物理技术为主的探查水源方法存在着诸多局限性，不能实时预报，主要技术瓶颈是常规的瞬变电磁法中线圈直径大，盲区较大，无法屏蔽，实现不了指向性探测，因此，进行以超小线圈瞬变电磁场为场源的瞬变电磁水害超前探测和预报理论与方法研究，对于矿井水害防治具有重要的理论意义和应用价值。.项目主要采用了理论分析、数值计算、实验测试、物理模拟、现场试验等多途径、多方法，对超小线圈瞬变电磁场监测水害相关基础科学问题进行系统地研究，主要包括：（1）全空间条件下超小线圈的瞬变电磁场在煤层和岩层中的传播特征，涡流场屏蔽理论与方法；（2）巷道前方不同含水体及不同含水量的超小线圈涡流场响应特征，不同含水体及含水量的信息识别和解译方法。（3）超小线圈瞬变电磁场的反演成像方法，噪声压制及校正方法；（4）超小线圈瞬变电磁指向性观测方法和水害超前探测预报方法等。.项目获得了磁棒线圈或空心线圈发射及磁棒线圈接收的不同组合的波场特征、岩层各向异性影响的波场特征、巷道前方不同含水体和含水量的超小线圈涡流场特征、全空间条件下巷-孔瞬变电磁场的响应特征以及电磁干扰的影响特征，分别提出了超小线圈涡流场单向屏蔽方法、超小线圈瞬变电磁指向性观测方法、电阻率计算偏低校正方法、基于 LBA-BP 的含水体不同含水量的信息识别方法和定量预测解译方法、利用方差比来识别强电磁干扰噪声及压制方法、利用拟合函数法和比值曲线法对金属体干扰的校正方法、基于阻尼最小二乘法的2.5维反演计算方法、基于拟地震合成孔径成像的高分辨率电性界面成像方法等，建立了超小线圈瞬变电磁场进行水害超前探测预报的波场传播基础理论初步构架，提出的巷道水害超前探测预报的瞬变电磁技术方法，经实际应用可以实现对巷道前方灾害性含水体的高效精准监测和定位，为水害超前预报奠定了理论和应用基础。