Coefficient of Superelevation for the Flow Using Movable Pillar in Channel Bend

To construct a bridge as a crossing building on a very wide river it might not used one span only, therefor, in middle of the river it is needed pillar as support. The existing of the pillars will change velocity distribution, surface water and topography of sediment, especially when the pillar is located on the bend of the river where the very large hydraulic can be hepened. Therefore, this study will be focused on the effect of the coordinate pillar to the superelevation coefficient. The research has done by making a model of channel with and without sediment for the both testing conditions, the pillar was moved by every interval of 30 on bends of the channel. Results of the research showed that the greatest value of Cs for the flow without sediment at the position of pillar of 0 at the bend of 120 is 3.413. On the otherhand, the greatest value of Cs for the flow with sediment was 3.509 wich was given by pillar at position 150 at bend of 30. Keyword – Channel Bend, Sediment, Pillar, Superelevation.