Seismosoft | Earthquake Engineering Solutions

Hi, I found static pushover analysis and adaptive pushover analysis. Can I do modal pushover analysis in here?

In the reference for the concrete confinement factor is recommended to follow the paper of Mander. That is fine. However, this paper deal with regular solid section. How can I find the confinement factor for a hollow rectangular concrete section?

Hi samyreza.

You can use SeismoStruct to perform individual pushover analyses, with loading pattern proportional to the vibration mode that you are considering. I'm afraid you will then have to carry out the combination of the several modes' response, in the end, manually.
You can use instead, or even for comparison, the adaptive pushover analysis, which manages to include the contribution of higher modes to the structural response all at once.

Regarding your second query, I would say that not much is known until now for confinement factors on hollow cross sections. You can try to evaluate the effectively confined area, depending on the characteristics of the trasverse reinforcement, which may sometimes not provide as much as confinement as one would expect. I would then say that in this sort of approximation, you should be conservative so as to account for this uncertainty.
I can also suggest you to look into a recent work (2009) from Vassilis and Kappos, entitled "Numerical study of confinement effectiveness in solid and hollow reinforced concrete bridge piers: Methodology", which addresses that issue.

Cheers