I use USD most of the time for reinforced concrete unless I'm working on
hydraulic structures, in which case, you need to know the working stresses
to design for crack control. For hydraulic structures, I normally check both
ways, with ASD controlling between control joints, and USD controlling at
waterstopped control joints where I reduce the steel. For footings, you end
up doing the calculations in both
I use ASD for steel for most routine work, and whenever I need to know the
working stresses to design for fatigue. I use LRFD occasionally for steel.
For bridge work, I use LFD. The LRFD requirements for bridges are more
complicated and I haven't used it yet.
I use ASD for masonry unless I'm working with tall walls, where I may have
to use USD methodology to make it work.
From: npitera(--nospam--at)mmm.com [mailto:npitera(--nospam--at)mmm.com]
Sent: Wednesday, April 26, 2000 7:30 AM
Subject: Re: ASD vs. LRFD
My question to all you structural engineers who predominately use ASD over
is do you also exclusively use working stress design instead of ultimate
strength design for reinforced concrete?