Seite - 1397 - in Book of Full Papers - Symposium Hydro Engineering

The hydraulic behaviour of the old Gomti Weir with a fixed weir sill was resulting in changing water levels depending on river flows. This was resulting in a very small water surface during dry periods. 2.3. DESCRIPTION OF MAIN PARTS The main sections of the new weir were built on top of the existing concrete structure by removing more than 1 meter of concrete. The new weir slab has a thickness of minimum 1.20 m and is made of reinforced concrete. The crown of the rubber dam lies on EL 106.0 m, the design height of the reservoir at EL 105.50 m. Fig. 3 Cross section through main rubber dam section For the regulation system water filling is foreseen. This system is providing a more stable and precise regulation range over the whole dam height and is designed for possible tailback up to EL 104.50 m also. The clamping rail for the 4 weirs sections is fixed in 2 steps with 0.1 m so that the height of rubber dam in downstream side is 3.20 meter. The rubber membrane is double-clamped and has a minimum wall thickness of 16 millimetres, with three woven fabric reinforcement layers to provide sufficient rupture strength. In case of flood the rubber dam will be regulated automatically according to the flow until the whole membrane is completely deflated to the fixed weir sill. 1397