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http://dx.doi.org/10.9720/kseg.2015.1.57

Numerical Analysis of the Seepage from and Stability of a Mine Waste-dump Slope during Rainfall  

Song, Young-Suk (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources)
Publication Information
The Journal of Engineering Geology / v.25, no.1, 2015 , pp. 57-66 More about this Journal
Abstract
A numerical analysis was performed of the seepage from and stability of a mine waste-dump slope in Imgi, Busan, considering rainfall intensity. The 40-45° slope angle of the waste dump is relatively steep, and the depth of the waste dump down to bedrock is 7-8 m. The groundwater level was 6.6 m below the surface. Various laboratory tests on samples obtained from the waste dump were performed to determine the input data for seepage and stability analyses of the waste-dump slope during rainfall. The results of seepage analysis for various rainfall intensities using the SEEP/W program show that the wetting front moved down with increasing rainfall duration. When the rainfall intensity was > 50 mm/ hour and the duration was > 24 hours, the waste dump became fully saturated because the wetting front reached the groundwater level. The results of slope stability analysis coupled with seepage analysis using the SLOPE/W program show that the safety factor of the slope decreased as the wetting front moved down due to rainfall infiltration. After continuous rainfall for 5-6 hours, the safety factor of the slope suddenly decreased but then recovered and converged. The sudden decrease was induced by an increase in pore-water pressure and a decrease in matric suction down to a certain depth as the wetting front approached the potential sliding surface.
Keywords
waste-dump slope; rainfall; seepage analysis; slope stability analysis; wetting front;
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
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