International Journal of Civil Engineering
http://ijce.iust.ac.ir
18
agent2
en
jalali
1394
9
1
gregorian
2015
12
1
13
4
online
1
fulltext
en
Effects of blanket, drains, and cutoff wall on reducing uplift pressure, seepage, and exit gradient under hydraulic structures
Water-Hydraulic Structure
Water-Hydraulic Structure
Research Paper
Research Paper
<p>Upstream blankets, drains and cutoff walls are considered as effective measures to reduce seepage, uplift pressure and exit gradient under the foundation of hydraulic structures. To investigate the effectiveness of these measures, individually or in accordance with others, a large number of experiments were carried out on a laboratory model. To extend the investigation for unlimited arrangements, the physical conditions of all experiments were simulated with a mathematical model. Having compared the data obtained from experiments with those provided from the mathematical model, a good correlation was found between the two sets of data indicating that the mathematical model could be used as a useful tool for calculating the effects of various measures on designing hydraulic structures. Based on this correlation a large number of different inclined angles of cutoff walls, lengths of upstream blankets, and various positions of drains within the mathematical model were simulated. It was found that regardless of their length, the blankets reduce seepage, uplift pressure and exit gradient. However, vertical cutoff walls are the most effective. Moreover, it was found that the best positions of a cutoff wall to reduce seepage flow and uplift force are at the downstream and upstream end, respectively. Also, having simulated the effects of drains, it was found that the maximum reduction in uplift force takes place when the drain is positioned at a distance of 1/3 times the dam width at the downstream of the upstream end. Finally, it was indicated that the maximum reduction in exit gradient occurs when a drain is placed at a distance of 2/3 times of the dam width from upstream end or at the downstream end.</p>
Cutoff wall, Blanket, Drain, Uplift pressure, Seepage, Exit gradient
486
500
http://ijce.iust.ac.ir/browse.php?a_code=A-10-2637-1&slc_lang=en&sid=1
H.
Khalili Shayan
h_kh_shayan@ut.ac.ir
`1800319475328460010496`

1800319475328460010496
No
University of Tehran
E.
Amiri-Tokaldany
amiri@ut.ac.ir
`1800319475328460010497`

1800319475328460010497
Yes
University of Tehran