# Masonry Study Problem



## kkillgore (Mar 5, 2010)

I was working some masonry problems from the Six Minute Solutions 2nd edition book which uses the IBC 06, ASCE 7-05. I noticed that they were using the 1/3 stress increase for wind and I was under the impression that the applicable load combinations from ASCE 7-05 Sec. 2.4 for allowable stress design do not allow the stress increase. What am I missing?


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## kewlman (Mar 5, 2010)

kkillgore said:


> I was working some masonry problems from the Six Minute Solutions 2nd edition book which uses the IBC 06, ASCE 7-05. I noticed that they were using the 1/3 stress increase for wind and I was under the impression that the applicable load combinations from ASCE 7-05 Sec. 2.4 for allowable stress design do not allow the stress increase. What am I missing?


ACI 530-05, 2.1.2.3:

The allowable stresses shall be permitted to be increased by one-third for load combinations with wind or earthquake.

You should have masonry building code.


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## kevo_55 (Mar 5, 2010)

Just as an FYI, I would read section 1605.3.1.1 of the 2006 IBC.

Remember the hierarchy of codes. The IBC trumps everything except state amendments!

:2cents:


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## kewlman (Mar 5, 2010)

It seems ASD steel code (9th), masonry &amp; wood codes, by ASD method allow the stress increase, but IBC and ASCE do not allow it in most cases.

They will let you know whether the increase should be included or not in the PE exam, because it is "permitted", not "required".

I've seen the stress increase in the real buiding design calculations sometimes.

Have you guys ever used the stress increase at work?


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## kkillgore (Mar 5, 2010)

kewlman said:


> It seems ASD steel code (9th), masonry &amp; wood codes, by ASD method allow the stress increase, but IBC and ASCE do not allow it in most cases.
> They will let you know whether the increase should be included or not in the PE exam, because it is "permitted", not "required".
> 
> I've seen the stress increase in the real buiding design calculations sometimes.
> ...


We do not use the stress increase. As long as the test tells me to use it or not that is all I need to know.


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## scottsman (Mar 31, 2010)

Section 1605.3.2 states that allowable stresses are permitted to be increased by the material chapter of the IBC or referenced standard.

Go to chapter 21 Masonry and it references the ACI 530. Refer to section 2.1.2.3 (02 edition) and a 1/3 increase is allowed for certain load cases. Unless there are changes from the ACI 530-02 to the 05 it appears stress increased are allowed by the IBC.


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