Water Quality Survey and Its Application to Rock Slope Management at the Une Mine

Abstract

The Une Mine excavates limestone by the bench cut method at Mt. Buko in the Chichibu area of Saitama Prefecture, Japan. Since the final rock slope, which is the largest scale in Japan, is beeing constructed at Mt. Buko, long-term monitoring and analysis have been carried out for the safety management of the rock slope. From the previous researches, a significant relationship between groundwater behavior and displacements of the rock slope was revealed, and suppressing the displacements of the rock slope, i. e., the reduction of the crack displacement rate, was accompanied by the lowering the groundwater level. Based on these results, countermeasures against the slope stability are being carried out in the mine. In this study, groundwater samples in the mine were collected and analyzed to characterize the groundwater chemistry, and to understand how the water quality was changed by rainfall and rock layers was examined. The results showed that the groundwater was classified into three depending on the layers, and that the groundwater in the alternated layer sensitively affected the rock slope.

Keywords

• limestone quarry
• slope stability management
• water quality
• drainage drilling
• water pumping