Ground penetrating radar investigations in Upper Kama potash mines

Abstract

An understanding of the structure and state of the rock mass surrounding underground openings in the potash mines is critically important for safe mining, planning the methods of extraction of an orebody, and preventing the influx of ground water. Continuous common offset ground penetrating radar (GPR) data were acquired in the potash mine operated by the Joint Stock Company (JSC) Silvinit (Russia) as part of an investigation of both pre-existing fractures exposed by mine workings and other anomalous geological structures. During the course of GPR investigation, the electrical properties of salt-bearing units were determined, site-specific data acquisition techniques and object-oriented data processing schemes adapted to the geological and geotechnical environment of the Upper Kama potash deposit were developed, and the methodology of 2-D and 3-D GPR data interpretation using interactive modeling was worked out. Open fractures and fault and fold features were successfully mapped using 2-D and 3-D GPR techniques. FK filtering significantly improved the reliability of fracture detection. Spatial models of mapped fractures were created using 3-D GPR imaging technique. Migration of the georadar data was required to obtain the true geometry of folded salt beds. The results of this GPR-based investigation demonstrate that the ground penetrating radar georadar method is capable of providing valuable information about deformation structures within the evaporite units of the Upper Kama potash deposit --Abstract, page iv