Investigations on Hydraulic Downpull Forces on Emergency Gate under High Heads with the help of Models

These investigations were carried out to measure the hydraulic downpull forces which would act on the Emergency Gate when subjected to high heads due to their operation under partial openings and emergency closures, Hydraulic model studies on the designing of Gates for Bhahra Dam indicated high order of downpull forces acting on them. Many modifications in the design of the emergency gates were put to tests to reduce the hydraulic downpull forces to the minimum and the results compared. The emergency gate with 17.5” (P) (444.50mm) lip length and having a cut of 45° to the bottom edge and with the base depressed into an arc of circle of radius 3” (76.20 mm.) and employing 18” (P) (457.2mm.) depth of recess reduced the hydraulic downpull forces to the extent of about one half [when operated under a head of 365’ (111.25m.)]