THE EFFECT OF RESERVOIR WATER LEVEL FLUCTUATION TO THE SEEPAGE ON EARTH DAM
Abstract: The modeling of
earth dam was carried out in a drainage and seepage tank to analyze the seepage
resulting from water level fluctuation in the upstream of the dam. The dam
models were made of the mixture of Mt. Merapi sand deposit with the soil of
sandy-silt from Wonosari area. The variations of sand content in the mixture
were 100%; 90% and 80% and the upstream slope inclinations were 1:1; 1:1.5 and
1:2. The result showed that the dams with more sandy-silt in the mixture have
smaller seepage and the dams with steeper upstream slope have greater seepage.
During rapid rising of water level, the dams with steeper upstream slope have a
high rising rate of upstream water level and higher height of downstream slope
failure. Moreover, during rapid drawdown, the dams with gentler upstream slope
have a smaller rate of upstream drawdown and lower height of upstream slope
failure. The dams with more sandy-silt in the mixture have a higher value of
rising rate and drawdown of upstream water level but lower height of downstream
and upstream slope failure. In the dam management, continuous monitoring of the
seepage resulting from reservoir water level fluctuation is required to avoid
dam failure.
Author: H. Sudardja
Journal Code: jptsipilgg120062
