Civil Engineering/eathquake load


QUESTION: Vx (EQX) & Vy (EQY) should be equal?!
(analysing a model in Etabs)

ANSWER: Dear Fakih

No need to be equal generally . It depends on you structural system in both directions.


---------- FOLLOW-UP ----------

QUESTION: Thanks for the reply...
My building isnt symetric so it's normal to have Vx(eqx)# Vy(eqy)?!
can I continue!? (static analysis on etabs 2013)

Dear Ibrahim

2 main reasons exist: 1: first mode of vibration period in 2 directions 2- The reduction factor in 2 directions.

If you have a significant anti symmetry you cant use the static analysis as finishing method and you must use modal-spectral method or time history ( dynamic methods) to complete and check the results. But I suggest that you have the static method as the main method in every situation because it is more significant and leading to better investigation in general. Details must be checked by sophisticated methods as I stated above.


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Babak Esmailzadeh Hakimi


I can answer questions in Structural Engineering, Earthquake Engineering, Project Management and Project Control topics!


I am experienced in the area of earthquake engineering in electrical power industry, i.e. Lifeline Earthquake Engineering. My focus has been on structural seismic design of power installations. Recently I have got involved in project management in the category of constructional engineering.

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Bs degree in Civil Engineering from Ferdowsi University ,1988, Mashhad Iran, Ms degree in Earthquake Engineering, Sharif University of Technology, 1993, Tehran, Iran

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