Gentlemen -
I am currently studying for the California SE-III and came across a load combination that I was unfamiliar with. I am looking over Ben Yousefi’s review manual for a design problem for a special reinforced concrete shearwall in SDC D.
The generic load combination goes from (1.2+0.2Sds)D+rho*Qe+0.5L & (0.9-0.2Sds)D+rho*Qe, where Sds =1.0, rho = 1.3
to 1.4D+1.3Qe+0.5L & 0.7D+1.3Qe
and then 1.46D+1.1Eh+0.5L & 0.63D+1.1Eh
Qe = rho*Qe, so really I think that the second set of equations should be 1.4D+1.3Eh+0.5L & 0.7D+1.3Eh, but I am totally baffled as to how you get from the second set of equations to the third. I can’t find any reference that points to increasing/ reducing the dead load and increasing the seismic loads by different factors.
What am I missing?
Thanks for your help,
Brian S Bossley, P.E.
7610 Olentangy River Rd
Columbus, OH 43235
(614) 847-1110 x 121 (ph)
(614) 847-1116 (fax)