矿井直流电法超前探测理论与成像方法研究

It is very significant to ensure safe production in coal mines through advanced detection forecast of severe geologic anomalies in front of the heading face. There are two prominent problems of inaccurate positioning and relatively short detection range of DC advanced detection in coal mines. By establishing an actual 3D roadway detection model, we aim at improving the computing efficiency and solution precision of 3D numerical simulation conducted by means of DC electrical method in coal mines under the conditions of large-scale 3D mesh and great electrical property dfference. 3D numerical simulation is carried out with algebraic multigrid method (AMG) and 3D physical simulation with flume simulation method. 3D space in underworkings is used extensively to analyze and study the detection capability of the monopole-dipole devices; thus an optimized 3D combination measurment system featuring long detection range, high resolution and strong capability of positioning anomalies to carry out multi-line joint 3D measurement effectively. Therefore, we have established direct 3D "multiple coverage" focusing imaging of anomalies responses data which adapts the combination measurement system, realizing the enhanced data stacking for geological anomalies and the improved resolution for weak signals and locating the accurate positions and ranges of the anomalies so as to increase the detection distance and leveling up the positioning precision. The research breaks through the current advanced detection using DC electrical method in coal mines which can be improved by this and better geological effect can be achieved, providing technical support to construct an intrinsically safe coal mine. The project outcomes are of great scientific significance and application value.

巷道掘进前方灾害性地质异常超前探测预报对保证煤矿安全生产具有重要意义。针对目前矿井直流电法超前探测存在的定位不准和探测距离小两个突出问题，通过建立实际三维巷道探测模型，着力提高大规模三维网格及电性差异大情况下矿井直流电法三维数值模拟计算效率和求解精度，采用代数多重网格法进行三维数值模拟,采用水槽模拟法进行三维物理模拟，充分利用井下巷道三维空间研究单极-偶极装置的探测能力，优化出探测距离大、分辨率高、异常定位能力强的三维组合单极-偶极装置测量系统，实现多测线联合三维探测。创建与单极-偶极组合装置相适应，对异常体响应数据具有三维"多次覆盖"特性的聚焦成像解释方法，实现对地质异常体响应数据叠加增强，提高对弱信号的分辨能力，圈出异常体的准确位置及范围，达到增大探测距离、提高定位精度的目的。本项研究将提高矿井直流超前探测技术水平及地质效果，为构建本质安全型矿井提供技术支撑，具有重要的科学意义和应用价值。

矿井直流电法是煤矿巷道掘进前方灾害性地质异常超前探测预报的主要方法，对保证煤矿安全生产具有重要意义。为解决目前矿井直流电法超前探测存在的定位不准和探测距离小两个突出问题，通过建立实际三维巷道探测模型，着力提高大规模三维网格及电性差异大情况下矿井直流电法三维数值模拟计算效率和求解精度，采用代数多重网格法进行三维数值模拟、水槽模拟法进行三维物理模拟，充分利用井下巷道三维空间研究单极-偶极装置的探测能力，建立了探测距离大、分辨率高、定位异常能力强的井下直流超前探测三维组合单极-偶极测量系统及三维聚焦成像资料解释方法，实现了对异常体的准确三维定位，定出异常体的确切位置及其范围，多次井下现场试验及应用表明，探测含水异常体厚度与深度比由原来地面指标的10%，提高到了5%～7%，最大探测距离达100m，达到了增大探测距离、提高定位精度的目的。项目的科学意义在于完善了矿井直流电法探测理论，澄清了长期以来一些混乱认识，提高了矿井直流电法超前探测技术水平及地质效果，为构建本质安全型矿井提供了有力的技术支撑。项目成果已在国内主要煤矿的60多个工作面巷道掘进超前探测中得到应用，并都取得了显著的地质效果，获得了巨大的经济效益和社会效益，为保障煤矿安全高效生产发挥了重要作用。