29-08-2014, 03:46 PM
A barrage is a diversion headwork, which is employed to divert inflows into the canal from a river. In a barrage the crest is kept at low level and the gates alone affect heading up of water. During the floods, the gates are raised to pass the high flood flow. When the flood recedes, the gates are lowered and the flow is obstructed, thus maintaining the required pond level at the upstream of the barrage for feeding the main canal under gravity
Barrages are usually made of masonry, plain cement concrete or reinforced concrete, depending on the nature of foundation encountered, availability of construction material, dewatering problems, economy of construction, etc. A barrage can have gravity or a raft floor. In recent years, the hydraulic and structural engineers have taken up are seized upon the important task of evolving safe and economic design criteria for barrage raft floor due to
several advantages such as less excavation and dewatering, lesser construction time, superior flexural behavior