×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

building moving laterally under gravity loads

building moving laterally under gravity loads

building moving laterally under gravity loads

(OP)
Hi guys,

When core walls location is eccentric and the building is displacing laterally under the gravity loads, is there any limitation to such kind of limitation ?

thank you

RE: building moving laterally under gravity loads

Geez! How much lateral movement do you have? The tolerance under gravity loads only is typically "ZERO"! Is there differential settlement? How long has this been going on? Have you set up any form of monitoring? Is there any evidence of distress? If there is differential settlement, the frame of the building might be undergoing more displacement than designed.....>>>>higher stresses. What type of building frame is it?

RE: building moving laterally under gravity loads

Sounds like the Leaning Tower of Pizza - and foundation problems.

Mike McCann
MMC Engineering

RE: building moving laterally under gravity loads

Could be movement induced by vibration too. Any construction or boaring projects nearby?

Mike McCann
MMC Engineering

RE: building moving laterally under gravity loads

(OP)
Guys please calm down. the building that i have has a triangular shape with core wall at one of the 3 sides. at ground floor, some columns are being transfered through thick drop beams. the foundation is modeled as a fixity so no foundation problem. i Have joined as attachement a typical floor layout. It is 12 story and the max diplacement is coming around 8cm.

RE: building moving laterally under gravity loads

(OP)
the 3D model is done using Etabs and after running the analysis, i noticed that the building was moving laterally probably to the torsion which is the 1st mode here.

RE: building moving laterally under gravity loads

So it isn't a real building picking up its skirts and walking off the site?

BA

RE: building moving laterally under gravity loads

BAretired...lol

Chekre....Have you considered that the heterogeneous nature of your model might be introducing errors?

RE: building moving laterally under gravity loads

Oh... So this is the leaning tower of Etabs...

Mike McCann
MMC Engineering

RE: building moving laterally under gravity loads

I guess problem is in your transfer level , provide supports there and see is your building still move or no

RE: building moving laterally under gravity loads

(OP)
Ron The model is ok and no errors. I rechecked it. Any ideas or suggestions ?
Thanks

RE: building moving laterally under gravity loads

What you have is differential shortening of the columns and shear walls due to the difference stresses in these elements. This effect induces a lateral displacement on your structure because the core walls are eccentric. The displacements you get on the model are unrealistic as a significant part of the elastic portion of the vertical displacement is compensated in each floor construction.
What you might do the eliminate this issue is a) include the construction sequence in the model or b) increase the axial stiffness of the columns in order to get the same vertical displacements in the walls and in the columns (beware of the side-effects associated to the change of the global lateral stiffness).

Hope it helps

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources