Hello

I wanted to ask about the implementation of accidental torsional effects.

Typically, there are two ways in which you can apply accidental torsion:

• apply static torsion
• directly offset the masses in the model

The latter approach is more preferable because in case of dynamic analyses further amplification factors wouldn't be required e.g. according to ASCE 7-10.

I have the following questions regarding this:

1) Does mass eccentricity need to be included in the eigenvalue analysis? I found an ETABS worked example, from which my understanding is as follows:

• When applying static torsion in spectral analysis, mass eccentrity is not included in the modal analysis
• If the masses eccentrictity is applied in spectral analysis, this needs to be considered in eigenvalue analysis as well

2) Are these torsional effects applicable to other structures than just buildings e.g. bridges?

3) The codes are not very explicit regarding how exactly accidental torsional effects are considered in pushover analysis. Since pushover is a static analysis, does it need to be further amplified? Does mass eccentricity need to be included in the corresponding eigenvalue analysis?

Thanks