www.sefindia.org

[rajancivildesign@gmail.co]

Dear SAFIAN,
There are many dams constructed in PWD and TNEB in Tamil Nadu very long back.
Most of the dams are of masonry construction. 100% leak proof is not possible.
There is no provision in the code about permissible limit of leakage allowed in Dam. Is there any empirical formulae to find permissible leakage in Masonry Dam.
V.M.RAJAN.

[dbpatankar]

Following presentation gives some idea about the question you asked.

Specifically the 10th slide

http://home.iitk.ac.in/~priyog/Design%20of%20Earth%20Dam.pdf

I hope this helps.

[vikram.jeet]

Not involved in dam design, listing following IS codes which may
help
IS 13645 Guidelines for guniting of upstream face of masonry Dam
IS 12200 COP for provision of water stops at transverse contraction joints in masonry
and concrete dams
IS 8605 COP for construction of masonry in Dams

IS 11293(part II ) - - guidelines for design of grout curtains for masonry and conc gravity dams

best regds

vikramjeet


Dear SAFIAN,
There are many dams constructed in PWD and TNEB in Tamil Nadu very long back.
Most of the dams are of masonry construction. 100% leak proof is not possible.
There is no provision in the code about permissible limit of leakage allowed in Dam. Is there any empirical formulae to find permissible leakage in Masonry Dam.
V.M.RAJAN.
-- ­­

Posted via Email

[atul_123]

[prof.arc]

Dear Mr. Rajan,



I find the topic unusual for this forum as we rarely discuss "DAM"
However, assuming that you have experience in designing dams - whether plain concrete or masonry, you must be aware of design requirement for UPLIFT conditions. Most Dams - definitely all recent ones - must be having drainage galleries. I believe you must have walked through those galleries.
In quite a few, including that made of concrete, you would have noted a copious flow of water in the large gutters of the drainage gallery.
Wetness of the downstream face of a Dam is not a design worry - at the most the uplift pressure diagram may have to undergo some modification.


Even in buildings which are built in high water table region, uplift pressures must be considered and usually relief is provided by collecting the outflow in a sump and pumping it out.


It is mandatory for buildings in USA which have basement, to have a sump well and provision to pump it out.


sincerely
ARC

On Fri, Sep 23, 2011 at 11:11 AM, rajancivildesign <forum@sefindia.org (forum@sefindia.org)> wrote:

[lkjain.ngp]

Permissible leakage should depend up on following criteria.
1. Exit velocity of leaking water should be less (by margin of factor of safety) than the one which can cause erosion of the mortar in the masonry. Loss of strength of masonry will also result in reduced life of dam.
2. Masonry dam's main purpose is to store water. and leakage means loss of precious water. Hence leakage should be negligible for economic advantage of dam.
 
L. K. JAIN


On 23 September 2011 11:11, rajancivildesign <forum@sefindia.org (forum@sefindia.org)> wrote:

[freedom]

what should be the exit velocity? quantitative wise

Posted via Email

[rajancivildesign@gmail.co]

Dear Sir,
Thank you for the information given in the forum. The ppt given is for earthen dam. Also as mentioned by Prof. Arc Drainage Gallery is provided in Masonry Dam for the leakage purpose. There is no accurate formula for calculating leakage. A thumb rule for calculating leakage is  {0.01 x Wetted area in sq. feet/1.75} in gallons per minute. This can be converted in terms of litres/ minute. I don't  know whether this formula is used for calculating leakage  in practice.
V.M.RAJAN.

[ishwarch59]

[ishwarch59]