Mineral and Energy Economy Research Institute of the Polish Academy of SciencesPoland
The geological structure of most Polish mining regions is rich in groundwater, making shaft sinking difficult. In recent years, more than a dozen shafts, some almost 700 m deep, have been sunk in Poland using various methods of water hazard elimination. The vast majority of shafts that pass through aquifer formations have been sunk using artificial rock freezing, waterproof tubing, and concrete lining. Generally, this system has proven to be very effective. However, there have been cases of complications during sinking, including occasional flooding. This paper presents two cases of highly problematic flooding in shaft sunk using the freezing method, both leading to considerable construction delays and a significant increase in shaft sinking costs. The first case involved water inflow into the bottom section of the R-XI shaft at KGHM with rocks near the melting point of ice. In the other case, problems occurred passing through an Albian layer in the S. 1.3 shaft sunk for the Lubelski Węgiel Bogdanka S.A. mining corporation, where the freezing process was carried out while it was necessary to heat the rocks in the upper part of the shaft to protect the final lining from damage.
Part of the book: Mining Techniques