Clause 2.1.2.3 ACI530-05: allowable stresses increase 1/3 for masonry

[Oversee]

Clause 2.1.2.3 ACI530-05: allowable stresses increase by 1/3 for masonry

Three load combination C) D) and E) are allowed for this strength increase, besides those “permitted by the legally adopted building code”:

1. D+L+(W or E)
2. D+W
3. 0.9D+E

My load combination has an extra ingredient: crowd loading (C). Following combination has been used to design masonry infill panels.

W+C

Building code from the local (Saudi) does allow an increase in allowable stress provided these load combinations are “caused by rate or duration of load”. Crowd loading is a short duration action and shall this be treated like wind or seismic load and use FOS=1.33 in flexural and compression design?

I wish to thank you all in advance.

 

[Lion06]

I use IBC which prohibits stress increases unless you use the "alternate" load combinations. They are similar to yours, but greater in number. Do you NEED the allowable stress increase? Is the stell or masonry controlling the design? It sounds like this is a pure compression load on a wall, is that true? Can you add grouted cells, more reinforcement, use a thicker block, or higher f'm?

 

[Oversee]

Crowd load is perpendicular to the wall face. I had solved this problem by using a thicker wall. F.O.S.=1 is maintained. Thanks!