cracked section

[Polibio1963]

Hello guys,

I have a silly question to ask about the UBC97: following the requirements of UBC97 1630.1.2 in my 3D model of a Concrete structure I have used the reduced Inertia properties following the
requirements of ACI 318-05 section 11.10.1. The question is: It is not clear to me if I have to use the "cracked model" only for the Evaluation of the displacements or also to design
the reinforcement of the columns and beams ?

Thank you in advance

 

[ahmedhegazi]

reduced section property is used for analysis and then you design according to the stress extracted from this analysis,same analysis model is used for interstory drift check as per UBC97,if you check serviceabailty under DL,LL or WL you should use gross section properties without reduction .

Hope this can help