Dynamic Analysis According to ACI & UBC

[faisal45]

When a concrete building should be considered for dynamic analysis? what will be the specification according to ACI & UBC code.

 

[asixth]

I think over 50m. Anything below that mode shapes get a bit funny partcularly when you build an FE model with slabs and verticals meshed and many DOF's. I can't comment on ACI or UBC

 

[JoshPlumSE]

The UBC will have specific requirements related to mass or stiffness irregularities. Section 1629.8 (1997 UBC) is titled "Selection of Lateral-force Procedure". Best to start there. In that section you can generally go up to 73 meters for regular structures.

 

[msquared48]

I would look to the IBC rather than the UBC, depending on the requirements of your local jurisdeiction.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[JoshPlumSE]

Good point Msquared! I had assumed that he was reviewing an existing structure and wondering how the original engineer was able to justify not using a dynamic analsyis. Other than that, I would agree that the current building codes (i.e. the IBC) would be the place to start.