Results for a structure subjected to two earthquake load sim

[zsherliza]

Hi Vesna,

Is it possible for a bridge to move only in the transverse directions, no matter in whatever mode i.e. I have displayed mode shapes of the first 8 modes, and they only move in the transverse
directions. For your information, I applied gravity load, and 2 earthquake loadings simultaneously ( following the 30% rule), as recommended by El Nashai et. al. I have very carefully modeled and apply loads as shown in examples and manual. My concrete section is 1500x3500 (local y x local z axes), I have subjected it to 4 load combinations. It seems that all combinations resulted in transverse directions only.
Please help me clarify this matter.
Thank you.

Zsherliza

[vesna]

from my experience, the common is to have first mode in transverse direction and the second is longitudinal. I do not have idea what can cause your bridge to move in transverse direction only.

[zsherliza]

Hi again,

Has anybody experienced the same problem? I have rechecked my model and just couldn't find explanation of the behavior.

Thanks.