Dam construction across a stream has a far historical background of application to get hold of water storage for agricultural or water supply purposes. There are several types of dams in practice today to go with the site conditions such as;
I. site topography & height availability,
II. Geological stability and geotechnical suitability of soil/rock types,
III. Flow availability and flood hydrology.
The invention introduced herein, ‘Water fill dam’ is to meet economy at the first place, by filling water in to the dam in order to provide necessary weight for stability. Secondly, it provides easy maintainability, by introduction of entirely automatic and non electrical operations. In the third place, it is safe enough against geological movements and earth quakes too, because it has a considerable degree of flexibility.
Advantageous Effects:-
1. Economy in dam construction is the biggest advantage and a huge concrete volume is replaced by water as a filling material, in this technique.
2. Automatic delivery unit reduces labour and cost for operations. Electrical operation systems may fail in case of a power& generator failure but the floater operated gate system, introduced herein, is operating under any worst situation.
3. Weighing the dam by filling water in to the rows and also releasing the weight according to the dropping water level of the reservoir, are automatically done by the ‘auto level controlling valve system’ introduced hereby and therefore the cost for O&M is minimal as a big advantage.
4. There is no need to monitor pore pressure, temperature, humidity, water quality or anything else regularly because such parameters are immaterial in consideration of safety of a water fill dam. Common failure modes which are critical for safety of any other types of dams are not applicable for a water fill dam such as;
5. Over flowing the dam in case of an unexpected flood is not a matter for a water fill dam because whole the dam length is designed to be a cascade drop in such a case of an emergency.
6. Piping through dam or any other seepage losses are vital for other dams but not applicable for a water fill dam because there is nothing to be washed off and water levels in the dam are automatically maintained.
7. Over turning of the dam structure which is fatal for any other dam is not applicable for a water fill dam because the lateral thrust of water pressure is distributed smoothly upon all the walls in rows evenly throughout the dam section, as shown in the guide sketch-07, so that no overturning is possible.
8. Wall panels are joined with rubber sealing and fitted to the piers at ends with flexible fillers and therefore on the whole, a water fill dam has a little bit of flexibility to sustain against earth quakes more successfully than any other type of dams.
9. Floater operations of gates are so smooth that no alarm is required to the downstream of the river. Perhaps one centimeter of a gate is opened at first and very gently and smoothly it may be increased in parallel with the increasing level of the reservoir and therefore an alarm is automatically given for the downstream communities by the gradually increasing flood levels in the river.
10. The component ‘de-silting’ in maintenance, need not specially to be attended because water issue on the whole, is done through bottom outlet gates as a big advantage.
11. The technique of water fill dam can be adapted for several other applications too such as;
I. Flood prevention dykes on river banks,
II. Tidal protection dykes in the coastal belts etc.