Need a book? Engineering books recommendations...
Return to index: [Subject] [Thread] [Date] [Author]
Re: drift calculation, 1997 UBC using ASD
[Subject Prev][Subject Next][Thread Prev][Thread Next]- To: seaint(--nospam--at)seaint.org
- Subject: Re: drift calculation, 1997 UBC using ASD
- From: "Robert J Bossi, PE" <rjbossi(--nospam--at)sonic.net>
- Date: Wed, 10 Nov 1999 16:25:42 -0800
Thanks for alerting me to the printing error. BUT does the errata make sense? If you compare Equations 12-6 (USD) and 12-10 (ASD), the USD equation will always provide a larger drift. The drift limit of 2-2.5%H is a constant dependent only on building height. If the errata is correct then a building designed by ASD will always be permitted to have more drift than when designed by USD. Regardless of the design method the drift used to compare to the maximum drift should be the same. The only way to do this is to use the USD load factors. Incidentally, Appendix C (pg. 444) of the SEAOC Blue Book requires use of the USD (1612.2) equations when the design is otherwise ASD. Anybody got ideas on this? Bob Bossi SDGSE(--nospam--at)aol.com wrote: > In a message dated 11/10/99 3:10:55 PM Pacific Standard Time, > rjbossi(--nospam--at)sonic.net writes: > > << Alex: > My code (1998 CBC, first printing) says:": ... the load combiations of > 1612.2 > shall be used." 1612.2 load combinations are USD and do not contain a 1.4 > factor. ie Eq 12-5 or 12-6. > > Bob Bossi > >> > First errata to UBC97 changes the reference to 1612.2 to 1612.3, which means > E/1.4 for drift calculations using ASD. It may not be the intention of the > author, but there is also the Rho factor which got misinterpreted. You Loose > some, you win some. >
- Follow-Ups:
- Re: drift calculation, 1997 UBC using ASD
- From: Michael Valley
- Re: drift calculation, 1997 UBC using ASD
- From: John Rose
- Re: drift calculation, 1997 UBC using ASD
- References:
- Re: drift calculation, 1997 UBC using ASD
- From: SDGSE
- Re: drift calculation, 1997 UBC using ASD
- Prev by Subject: Re: drift calculation, 1997 UBC using ASD
- Next by Subject: Re: drift calculation, 1997 UBC using ASD
- Previous by thread: Re: drift calculation, 1997 UBC using ASD
- Next by thread: Re: drift calculation, 1997 UBC using ASD
- About this archive
- Messages sorted by: [Subject][Thread][Author][Date]