Principal direction of the building? 1

[drile007]

What's the quickest way to determine the principal direction of the building?


Drile007

 

[Murali27]

Dirle

I am not sure of what is the structural system in the building,

I would say, quickly calculating section properties

Cheers

 

[drile007]

I was thinking about any system which is modeled by the Etabs.
Can I help myself with the modal participating mass ratio.

Drile007

 

[Murali27]

Drile

Yes, its correct

cheers

 

[GarthJ]

Try to determine the angle of the base reaction for the first fundamental frequency. Check out the CSI web site. There is an article posted there with the title something like "Dynamic Analysis to Satisfy Building Codes" (or something like that)

 

[drile007]

Thanks GarthJ...great readings. Now I see that looking for principal direction is meaningless if I do the right combination of modal maximums and spectra accelerations.

 

[RafikCGS]

One way is to perform a preliminary modal analysis; the principal direction corresponds to the direction of the first mode translational direction, translational first mode of vibration corresponds to the most flexible direction.