2006-08-27 04:54:45 · 10 answers · asked by gurna 1 in Science & Mathematics ➔ Physics
For strength :)
2006-08-27 04:57:27 · answer #1 · answered by JeffE 6 · 0⤊ 0⤋
All the answers so far relate to the fact that the water pressure at the bottom of the dam is greater than the water pressure at the top of the dam. This is true. However, nobody seems to have mentioned that the dam also has to support its OWN weight, which ALSO contributes to the structural requirements at the base.
2006-08-28 18:26:11 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Solid gravity dams are made of solid concrete. They withstand the pressure, or push, of water by their weight. In cross section, they are like a triangle, broad at the base and narrow at the crest. They are built in this shape because water pressure becomes greater with the depth of water. Whether a dam backs up water for a long or a short distance is not important. Pressure depends not upon how far water is backed upstream but upon its depth at the dam. Examples of solid gravity dams include Grand Dixence Dam (1961), on the Dixence River in Switzerland; Bhakra Dam (1962), on the Sutlej River in India; and Grand Coulee Dam.
2006-08-27 05:17:24 · answer #3 · answered by Littlebigdog 4 · 0⤊ 0⤋
There built broader at the base because there is more weight at the base, divers can only go down to certain depths because of the pressure on their lungs,
yet submarines can go much deeper because of the strength of the hulls.
Same thing with dams. need more strength to hold back the water as the depths increase.
2006-08-27 05:10:15 · answer #4 · answered by kylenstevo 1 · 0⤊ 0⤋
pressure under water = height below surface X density of water X acceleration due to gravity.. so at the base of the dam the pressure/force in the dam is higher than pressure at the surface. So dams will be thicker at the base in cross sectional view..
2006-08-27 19:27:30 · answer #5 · answered by A Bank 1 · 0⤊ 0⤋
beacuse as we go down the water's weight adds up (ie force) and sice greater the force and broader the base the pressure exerted on the wall becomes less as
pressure= force/ area
and hence ,lesser the pressure more durability and relibility is the result....and thats what architects are looking for !!!
2006-08-27 06:57:36 · answer #6 · answered by MIKE 1 · 0⤊ 0⤋
Because it would be rather stupid to build them broader at the top and also very difficult to achieve
If architects rather than civil engineers designed dams who knows what they would be like
2006-08-27 05:06:20 · answer #7 · answered by wimafrobor 2 · 0⤊ 0⤋
Do you mean "broader" at the base? as opposed to "broader" at the top? Or simply parallel all the way up?
2006-08-27 05:06:51 · answer #8 · answered by cycloneweaver.com 3 · 0⤊ 0⤋
That is where the pressure is due to the weight of the watter
2006-08-27 07:00:18 · answer #9 · answered by JOHNNIE B 7 · 0⤊ 0⤋
greater pressure is exerted the deeper the water is
2006-08-27 05:08:33 · answer #10 · answered by LoneWolf 3 · 0⤊ 0⤋