| View previous topic::View next topic |
| Author |
Message |
anand.shah1
SEFI Member
Joined: 26 Jan 2003
Posts: 13
|
 Posted: Fri Dec 24, 2004 11:33 amPost subject: permissible limit of drift |
 |
|
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 |
|
 |
ishacon1
...
Joined: 26 Jan 2003
Posts: 52
|
| Posted: Fri Dec 24, 2004 3:04 pmPost subject: permissible limit of drift |
|
|
Dear Anand,
You will need to increase the column sizes to cut down on the drift.
Also ensure that there is no torsion irregularity.
你可能想要增加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 |
|
|
saistructure
SEFI Regulars
Joined: 26 Jan 2003
Posts: 28
|
| Posted: Sat Dec 25, 2004 8:11 amPost subject: permissible limit of drift |
|
|
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德赛
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 |
|
|
Rudra Nevatia
...
Joined: 26 Jan 2003
Posts: 214
|
| Posted: Mon Dec 27, 2004 3:16 pmPost subject: permissible limit of drift |
|
|
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.netwrote:
| Quote: |
你可能想要增加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 |
|
|
|
|
Subscriptions
FAQ
Search
Memberlist
Usergroups
Register
Donate
Profile
Log in to check your private messages
Log in to website
