IBC 2000 ~ 2003, Base Shear

[recentgrad]

I have to update a calc of base shear from IBC 2000 to IBC 2003. I see only one eq (16-56) relevant. Is it so simple now? no consideration to SD1. Thx in advance for your comments

 

[SacreBleu]

Not so simple...Cs is computed from Sd, etc

 

[mrMikee]

Eqn 16-56 is for using the simplified procedure. Looking at section 9.5.5.2.1 in ASCE 7-02 you will see that there are 4 equations to be calculated. The first is for Cs and the rest are for the upper and lower bounds of Cs. The variables used are Sds, Sd1 and S1.

Regards,
-Mike

 

[14159]

The IBC 2003, through ASCE 7-02, equivalent lateral force calculations are almost identical to 2000. The approximate period calcs are a little different and I think they clarified the insane requirement to iterate to determine Ax. I can't remember if anything else changed, but the results end up being very similar.

14159