Slender Masonry Walls

[THERR]

Greetings All,

I have a general question on Slender Masonry Walls. We got into a debate here at the office over the question "Do we need to have special inspection performed on slender masonry walls or can we reduce the phi factor from .8 to .5 in order to eliminate the special inspection requirement". Any comments would be helpful. Thanks.

 

[JAE]

Which code are you basing your discussion on. It makes a difference.

 

[THERR]

1997 Uniform Building Code (UBC).

 

[JAE]

2105.3.4 discusses full and half allowable stresses and does not seem to ever directly refer to 2108 - Strength Design of Masonry.

Section 2108 does not ever directly relate or refer to 2105.3.4.

So your question is a good one - an apparent brain fart on the part of the UBC committee.

I would probably go along with your thought line of cutting the phi factor in half to replicate the concept of "half stresses". The concept is one of hitting the design with a large safety factor (2) in excess of the "typical" safety factor inherent in the allowable stresses of ASD. The phi factor adjustment does just that. There is no other adjustment in 2108 to account for the inspection issue.