Prevention of Groundwater Disasters in Coal Seam Floors Based on TEM of Cambrian Limestone

摘要

We analyzed the abundance and connectivity of Cambrian limestone aquifers (CL) using data from geological and hydrogeological boreholes, groundwater tracer tests, groundwater temperature monitoring, and surface transient electromagnetic exploration (TEM). Our results demonstrate that extremely well-developed small faults with an average density of number 73 per square km control the groundwater abundance and flow of the CL. The hydraulic conductivity of the CL aquifers estimated by tracer tests lies between 13,511 and 38,738 m/d, suggesting good connectivity. The surface TEM result of 4.91 km_(2)shows that areas with an apparent resistivity value less than 30 Ωm can be treated as an anomalous low-resistivity zone. This has been proven to be reliable by experience at the working face and can be used to determine water control measures for future mining. Using these data, we developed a series of preventive measures to mitigate potential floor water ingress related to future mining in the eastern area of the Pingdingshan coalfield No. 2 mine.