Mark,
I agree with your interpretation. The 1/3 allowable stress increase was not well understood and misused over the years. With the move to strength design there has been a move to dump it. Geotechnical engineer code developers are also in the process of getting rid of it for similar reasons.
Regards,
Harold Sprague
> Date: Sat, 5 Jan 2008 09:05:08 -0800
> From: markajohn@yahoo.com
> Subject: RE: Handrail Loads vs Short Term
> To: seaint@seaint.org
>
> Harold, Dr. Hamida, engineers,
>
It seems like the most significant place a one-third allowable stress increase is still permitted is when designing footings with the appropriate load combinations. I'm looking at footnote d on table 1804.2 of the 2006 IBC which specifies "allowable foundation pressure" and "lateral bearing pressure."
>
On the other hand, there is the requirement for a soil investigation in section 1802 for anything in seismic design class C or higher. An investigation could trump table 1804.2 and the one-third increase.
> Is that right?
>
> thanks,
> Mark Johnson
>
>
>
Share life as it happens with the new Windows Live. Start sharing!