|Abstract Submission No.
|Title of Abstract
|Optimising Design of Long Span Flood Gates for Coastal Reservoirs
|NAMITHA B*, SUGANYA S, SATYA KIRAN RAJU ALLURI, M V RAMANA MURTHY
|National Centre for Coastal Research
Chennai, Tamil Nadu, India
|Coastal reservoirs are gaining popularity these days as they can provide sustainable and reliable source of drinking water for coastal communities, particularly in regions where freshwater resources are limited. They not only provide fresh water but also prevent flooding during Storm Surge or Tsunami. They involve construction of dyke or bunds across the river or into the sea and store fresh water on the river side. The major challenge for these reservoirs is discharging flood water into the sea during extreme rainfall events, which is done using flood regulator. This operation becomes quite complex if the sea-side water levels during high tide are more than reservoir operating water levels. In this case, gates have to be closed during high tide and opened during low tide making operations complex (four times in a day in semi diurnal tide zones). The associated risk can be minimised by using a smaller number of long span gates. Conventionally, flood regulator gates are designed for a low span in rage of 15- 25m as it will be difficult to lift long span gates due to their massive weight. In this study three different configurations of vertical gates such as flat gate, flat gate with arch girders and lens shaped gate for 50m span are studied for flood regulator based on previously executed storm surge barriers. The gates are designed for storm surge event on the sea-side and maximum flood condition on the river side. A comparative study is carried out considering the quantity of material, ease of installation and operation. The study reveals that lens gates are ideal and optimum for long spans. However, if the gates have to be placed on control structures like ogee weirs due to hydraulic design, lens gate cannot be used due to non-availability of horizontal bottom and flat gates with arches need be considered.
|Long Span Flood Gates,Flat Gate,Arch Girder,Lens Shaped Gate,Coastal Reservoir
|Date Of Birth