www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

permissible limit of drift

 
This forum is locked: you cannot post, reply to, or edit topics.This topic is locked: you cannot edit posts or make replies.    www.sefindia.org Forum Index -> Past Discussions Year 2004
View previous topic :: View next topic  
Author Message
anand.shah1
SEFI Member
SEFI Member


Joined: 26 Jan 2003
Posts: 13

PostPosted: Fri Dec 24, 2004 11:33 am    Post subject: permissible limit of drift Reply with quote

I am designing two storey college building in zone 5.
caculated Storey drift is 17 mm .
and allowable is 0.004 * H as per code is 14 mm.
All columns and beams I have designed as per requirements of code 1893,13920
and 456.
Reinf. % dosnt exceed 2.6% in any column. Even beams are not so heavily
reinforced.
So, do  I need to change sizes of members to control storey drift ( though
it is not design requirement)?
or Any other suggestion?
I have considered rigid diaphram action bcs slab is rigid.

Regards
Anand

Posted via Email
Back to top
View user's profile Send private message
ishacon1
...
...


Joined: 26 Jan 2003
Posts: 52

PostPosted: Fri Dec 24, 2004 3:04 pm    Post subject: permissible limit of drift Reply with quote

Dear Anand,

You will need to increase the column sizes to cut down on the drift.
Also ensure that there is no torsion irregularity.
You may want to increase IY & IZ of beams to account for diaphragm
action of slab. This will automatically reduce your drift somewhat.

V.P.Agarwal

Posted via Email
Back to top
View user's profile Send private message
saistructure
SEFI Regulars
SEFI Regulars


Joined: 26 Jan 2003
Posts: 28

PostPosted: Sat Dec 25, 2004 8:11 am    Post subject: permissible limit of drift Reply with quote

Dear Anand,

Kindly inform which software you have used and how diaphragm action has been ensured while modelling. For which loadcase you got 17 mm drift?

Hiren Desai

Anand.shah@babtieindia.com wrote:
I am designing two storey college building in zone 5.
caculated Storey drift is 17 mm .
and allowable is 0.004 * H as per code is 14 mm.
All columns and beams I have designed as per requirements of code 1893,13920
and 456.
Reinf. % dosnt exceed 2.6% in any column. Even beams are not so heavily
reinforced.
So, do I need to change sizes of members to control storey drift ( though
it is not design requirement)?
or Any other suggestion?
I have considered rigid diaphram action bcs slab is rigid.

Regards
Anand

Posted via Email
Back to top
View user's profile Send private message
Rudra Nevatia
...
...


Joined: 26 Jan 2003
Posts: 207
Location: Mumbai

PostPosted: Mon Dec 27, 2004 3:16 pm    Post subject: permissible limit of drift Reply with quote

I am confused.

I was taught that arbitrarily increasing out-of-plane
stiffness of beams to account for diaphragm action
results in large off-diagonal elements in the global
stiffness matrix and the resulting system of equations
can be ill-coditioned giving wrong results from an
otherwise well behaved software.

But then this was thirty five years ago.

Rudra Nevatia

--- ishacon@vsnl.net wrote:
Quote:
You may want to increase IY & IZ of beams to account
for diaphragm action of slab.


          
__________________________________

Yahoo! Mail - Helps protect you from nasty viruses.

Posted via Email
Back to top
View user's profile Send private message
Display posts from previous:   
This forum is locked: you cannot post, reply to, or edit topics.This topic is locked: you cannot edit posts or make replies.    www.sefindia.org Forum Index -> Past Discussions Year 2004 All times are GMT
Page 1 of 1

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy