GPR Investigations in Upper Kama Potash Mines

Geohazards posed by surface subsidence accompany extensive exploitation of the potash deposits and cause serious damage to property, infrastructure and industry facilities on the surface. Undermined areas of the Upper Kama (Verkhnekamskoye) potash deposit within the cities of Berezniki and Solikamsk (Perm region, Russia) present a special threat as large chemical and power plants, roadways, railroads and gas pipelines are located within the subsidence zone. The significant losses of company and state budget due to replacement of the roadways and infrastructure in the risky area were reported after the catastrophic collapses at the mines BKRU-2 in 1988 and BKRU-1 in 2006. Studying of deformation of the rock mass surrounding the mine openings is very important for safe mining, planning the methods of extraction of ore, and, especially, preventing the catastrophic water inflow in the potash mines. Geophysical methods have proven to be an effective, nondestructive investigative tool, providing mining engineers with continuous information about the structure and geomechanical properties of subsurface material. Preliminary experiments in the Upper Kama potash mines show that the GPR (ground penetrating radar, georadar) method is capable of providing the most detailed and continuous information about the rock mass structure at distances of up to 40 m from the mine openings. About 6 km continuous common-offset GPR profiles were collected in the potash mine of the JSC “Silvinit” located near the city of Solikamsk (Russia) in order to develop the site-specific methodology of data acquisition, processing and interpretation. Data were collected at the upper mining level where the tension vertical fractures were exposed by the workings as well as at the lower level to estimate the extent of the fracture zone. The OKO (Logis, Russia) and RAMAC/GPR commercial georadar systems were employed for data acquisition. The software used for data processing and interpretation was REFLEXW (Windows OS) and OpendTect (Linux OS). Although the GPR method has been used in German and Canadian salt and potash mines for long time, the geological and geotechnical environments of the German and Canadian deposits differ significantly from those of the Upper Kama deposit. Consequently, the appropriate GPR acquisition, data processing and interpretation methodologies were developed. Because of intensive folding of different range, GPR data are significantly contaminated with diffractions and a migration is required to make the data interpretable. The results of data analysis show that the GPR method may be of great utility for detection of the small-scale fractures and the flexure folds at depths up to 20 m. The 3-D imaging technique has proven to be an effective tool for studying the geometry of the fractures. This study has the following results: the electrical properties of typical rock salt formation members were determined; the site-specific data acquisition technique and object-oriented data processing schemes consistent with the local geological and geotechnical environment were developed; and the methodology of 2-D and 3-D GPR data interpretation using interactive modeling was worked out.

  • Record URL:
  • Supplemental Notes:
    • This research was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
  • Corporate Authors:

    Missouri University of Science and Technology, Rolla

    Center for Infrastructure Engineering Studies
    Rolla, MO  United States  65409

    Research and Innovative Technology Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Kovin, Oleg N
  • Publication Date: 2010-1

Language

  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Figures; Maps; Photos; References;
  • Pagination: 17p

Subject/Index Terms

Filing Info

  • Accession Number: 01153167
  • Record Type: Publication
  • Report/Paper Numbers: UTC R165, Report No. 00016751
  • Contract Numbers: DTRS98-G-0021 (Grant)
  • Files: UTC, TRIS, USDOT
  • Created Date: Mar 23 2010 11:45AM