The seepage flow analysis of main dam stability in Way Sekampung dam development project

Abstract

Analysis using depression line method was conducted in two conditions, at normal water level (± 124 m) with a result of 1.11 × 10-3 m3/s and at flood water level ± 126.5 m with result 1.33 × 10-3 m3/s. Capacity shows (< 1%) the average enters the reservoir, making it safe from the danger of distress. Safety calculations for pipping showed a bigger value than the filtration flow speed indication at the average value of 4,638 ( > 4) which means that dam will not make pipping symptoms. Analysis conducted on the slope of the dam using slice method without entering the value of seismic coefficient obtained a safe number result in all loading conditions and the analysis by adding a seismic coefficient get a safe result except in two conditions, at elevation ± 126.5 m is  SF 1.05 and at elevation ± 124 m SF is 1.05.