Design Aspects of the Highest Run of the River Barrage on Permeable Foundation of India

Even though there is no unanimity in India on the definition of the term “Barrage”, as against the welldefined and accepted term “Dam”, but a general acceptance refers to a diversion structure with a series of gates across the river to pond water for irrigation, power generation, flood regulation etc., with a relatively small afflux. Another connotation relates to the foundation, which in case of barrages is mostly the original riverbed comprising of river-borne material viz. sand, cobbles and boulders. As a corollary, the barrages are generally of lesser height and less massive as compared to dams. The area of concern in this type of structures are soil structure interaction resulting in additional moments and shear forces and are of particular interest for reinforced rafts. These concerns grow proportionately with the height of such barrages. The paper deals with the hydraulic & structural design of a very high barrage (37 m from lowest excavation level) and the structure is typically a “dam on a permeable foundation” on Teesta river in the state of West Bengal in India. The structure was built in the period 2005–2010 and is performing its intended function ever since.