UJI DISPERSIVITAS BAHAN TIMBUNAN BENDUNGAN DURIANGKANG
Abstract
Dispersive clays have been identified as soils which highly erosive because they have a higher percentage of
dissolve sodium in their pore water than ordinary clays. The dominant sodium ions increase the thickness of the diffused
double water layer surrounding the individual clay particles. This causes the repulsive forces to exceed the attractive
forces so that the individual clay particles go into suspension in the presence of water. Their detrimental effect on the
performance of dams, canals has been recognized. Piping in earth dams which lead to the failure of dams due to the
presence of dispersive clays has been identified in Australia, United States, South Africa and many countries throughout
the world. This research presented the tests using various available methods to identify the degree of dispersive of
embankment material for Duriangkang dam, the first estuary dam in Indonesia. Analyses to the results were also
discussed. The decision not to include the suspected dispersive and moderate dispersive clays in the embankment of
Duriangkang dam was taken in order to minimize the risk of eroded and piping progress in the dam body.