Study on the development pattern of continuous aquitard water-conducting fracture zones and rock layer detection...

The northern part of Guizhou Province is rich in coal resources, but mining safety is threatened by water - bearing strata. This study zeroes in on Longfeng Coal Mine in Guizhou Province and delves into the issue of water damage in coal mines under complex geological conditions. By applying a range of methods-empirical formulas for water - conducting fracture zones from massive data fitting, overburden theory, numerical simulation, DC electrical method exploration, and borehole camera detection-the study reveals that as the working face advances, the overburden fracture zone expands sideways and compacted in the middle. The fractal dimension of the water - conducting fracture zone fluctuates remarkably, showing a clear link to water inrush. Based on fracture development patterns, an integrated surface and underground exploration drilling scheme was designed and carried out. The scheme successfully determined that the water - conducting fracture zone's development height was between 44 and 59 m, with a fracture - to - mining ratio of 15.39-20.63. The detachment water accumulation space lies in the hard - soft interlayer formed by the Longtan group limestone and the underlying silty mudstone. In engineering practice, the rock - layer detection borehole camera was upgraded. Its image - presentation effect was optimized, and the detection depth of the borehole was increased. Additionally, a multi - angle detection borehole camera with waterproof, mud - proof, and cold - resistant capabilities was designed, and technical improvement measures were proposed to adapt to more complex underground conditions and ensure more accurate rock - layer information acquisition. These innovations provide significant guidance and reference for preventing water inrushes in mines and protecting groundwater resources under similar geological conditions.