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wind load on irregular building asec 7-98
dear friends,
i have got a irregular building of "l" shape. height > 60'
as per asce 7-98, what to assume for l & b values....in the caluculation of pressure coefficients...
dimensions (in ft) of the building looks like this
103'
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_________|_______|
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124' | |
|____ _ ___________|
289'
can we apply the wind forces to the individual wings..on either direction??
your input will be appreciated...
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ok friend.. this may sound like a commercial but really it is not. i have been using software written by standards design group, inc. this software was developed by sdg and dr. kishor c. mehta, past chairman of the asce wind load committee, director of the wind engineering research center and horn professor of civil engineering at texas tech university severed as one of the many prominent consultants with sdg.
i have been using it for years and it fairly produces accurate results.
this software has the capability to produce loads on irregular structures such as your. you can build the plans on the screen before you compute your loads.
i use it exclusively for all of my calculation. check it out at this web site
mr. murali,
it seems two buildings are there in your skectch from the dimensions concern and two are perpendicular each other. from my experience for the wind applications as below. regardless of the software or programs you use , the basic procedure i am putting to you.
wind lateral direction: apply independently on frame design in each buildings repsectively. give allowance for the sway allowance to other building by means of keeping seperate frame or by giving space with flexible covering.
wind longitudinal direction: for main building check all with longitudinal forces as they are occur in actuals. if the other buidling is fully covered / shielded ( i.e if the height is less than main bldg or equal to ) , take the longitudinal forces equal to 65% ( 0.8/(0.8+0.5). for these forces , bracings are to designed in case of steel buildings. if its height is greater than other, consider by proportionate to height factors in same ratio.
murali,
your sketch didn't come out too well in your post. i think when you click on submit, the site puts in some tabs spaces & formatting. i know i can't see what your bldg looks like. could you clarify this?
i think an important point that you need to clarify is heights of roof in both wings.
i attended an asce sponsored seminar on wind loads in asce 7-98, i learned a little about this there. this has a rather lengthy reply, and if you can clarify the building layout more, i can try and make one.
the point i learned at the seminar was, "... keep in mind what the approaching wind will see." you can take this a long way towards figuring out what b/l, what h to use for calculating wind on the various parts of your bldg, and keep in mind, you probably will need to figure for each orthoginal direction, and probably some oblique directions as well to find the most critical.
i think this is one of a number of areas that ought to be covered more completely in the asce code provisions. i'm interested in your problem, but need a better picture to understand it. if you are unable to post a better layout, would you mind sending something to me by e-mail?
regards,
chichuck
thanks lufti / kvram /chichuck
you are right.post has not come nicely.
this is rcc shearwalled flat plate buildings of 130 feet height.the two blocks are at the same height.
chichuck & kvram - i mailed you the building plan.
please let me know your valuable suggestion on that and how to interpret the code at this given situation.
thanks
-murali |
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