Bhagirath Joshi

Help required for analysis in etabs

10 posts in this topic

Hello everyone,

I wanted a help regarding the problem I've been facing during building analysis using etabs. The analysis displays the minimum steel for every column, what might have been the error or problem?

Also ,is providing diaphragm for area components and meshing them necessary during analysis of building in etabs?

Share this post


Link to post
Share on other sites
33 minutes ago, Bhagirath Joshi said:

The analysis displays the minimum steel for every column, what might have been the error or problem?

There may be several reasons for this. For example,

- provided columns are of a larger size, or

- there are a number of shear walls, or

- you might have erroneously assigned support property to the column joints at all storey levels, instead of those at base level, etc.

You should recheck your model carefully to determine, what might be the real reason for the results obtained.

45 minutes ago, Bhagirath Joshi said:

Also ,is providing diaphragm for area components and meshing them necessary during analysis of building in etabs?

Assigning of diaphram is necessary for proper accounting of stiffness of the structure, to resist lateral  forces (earthquake etc).

Meshing is essential for the transfer of slab load to the edge beams more uniformly.

HTH

Share this post


Link to post
Share on other sites

thank you for you previous suggestion. I'm still facing the same problem. I checked the model carefully, assigned restraint at base only and provided appropriate column size. Can I get any more suggestion please!

Share this post


Link to post
Share on other sites

You haven't provided any details regarding your structure, e.g., geometry, spans, no. of stories, building usage, seismic zone, etabs version being used, etc. etc. As such, it is difficult to give more suggestions.

If you could attach your model file here, people here might help you in a better way.

Share this post


Link to post
Share on other sites

I have been using IS code for building analysis on ETABS 9.7.4  . The building is for residential purpose seismic zone V. I ve attached the 3d model and layout plan for the building. Thank you!

123.jpg

1PLAN.jpg

Share this post


Link to post
Share on other sites

Dear Uzair, I'm also facing the same problem.my building is in zone 2A,soil sd,all spans are less than 25ft,slab thickness 6",size of columns and beams are 12"x30" and 9"x18" respectively. Seismic load cases are 4. End result is all columns are having steel 1%.is it ok to have same %age in all columns? Or something is definitely wrong?

Secondly building shape is pretty regular and no of stories are eight.rigid diaphragm assigned.etabs version 9.7.5. but i just remember i erroneously defined 25% live load in mass source command as the building is for purely residential purpose as against Warehouse or a garrage where we define 25% of L.L.?

Share this post


Link to post
Share on other sites

Dear Abid 

please share your model and architectural plans, so that somebody could review it. one major reason is of assigning supports at all levels and second is oversize members(columns,beams) as uzair sab mentioned above, 3rd is shorter spans and equal loads going to columns.

regards

Share this post


Link to post
Share on other sites

Dear waqar I'm uploading architecture and edb file of the model.i have separated the building by providing expansion joint.the file in etabs model is one portion of the building, I'm working on it.secondly if we dont want to provide expansion joint thn wat to do? coz when i model the entire building then lots of errors are coming so i separated the building now there aren't any errors.all suggestions will be highly appreciated.thnx n regards

STATIC MODEL.EDB

STATIC MODEL.$ET

AMMALGAMATION PLAN-Model.pdf

Share this post


Link to post
Share on other sites
On 1/21/2017 at 2:18 PM, Abid Qasmi said:

Dear waqar I'm uploading architecture and edb file of the model.i have separated the building by providing expansion joint.the file in etabs model is one portion of the building, I'm working on it.secondly if we dont want to provide expansion joint thn wat to do? coz when i model the entire building then lots of errors are coming so i separated the building now there aren't any errors.all suggestions will be highly appreciated.thnx n regards

STATIC MODEL.EDB

STATIC MODEL.$ET

AMMALGAMATION PLAN-Model.pdf

Dear all,i found out the reason why column reinforcement was 1℅ in all columns and it was that i had erroneously assigned oversized column dimensions in some columns. But my second querry yet remains unanswered that is whether the building be modelled as a whole or separated into two portions in order to avoid errors.thnx n regards

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now