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Re: UBC '97 Sec 1633.2.4 Deformation compatibility

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Actually, having thought about it, I retract my previous statement. It is
probably not a typo. However, I seem to recall that the SEAOC blue book allowed
you to assume a 2.5% storey drift without calculating the DeltaM for every
element in the structure.



David Chan wrote:

> In regards to Section 1633.2.4 of the 97 UBC, my copy also has 0.0025 times
> the story height rather than the 0.025 mentioned in previous posts.  Is this
> a typo in 97 UBC?
>
> David Chan, EIT
> Los Angeles, CA
>
> -----Original Message-----
> From: Steve Hiner [mailto:shiner(--nospam--at)folsom.ca.us]
> Sent: Thursday, May 25, 2000 10:11 AM
> To: 'seaint(--nospam--at)seaint.org'
> Subject: RE: UBC '97 Sec 1633.2.4 Deformation compatibility
>
> Per UBC 1630.10.2, DeltaM shall not exceed 0.025 times the story height for
> structures with T < 0.7 seconds ...
>
> UBC 1633.2.4 gives you the choice to either use the expected deformation
> based on your "calculated" DeltaM, or the expected deformation assuming that
> DeltaM is equal to the maximum allowed value of 0.025 times the story
> height.
>
> Steve Hiner, SE
> Folsom, CA
>
> ps - I appear to have a misprint in my 1998 "California" Building Code for
> Section 1633.2.4 (p. 2-19) where the 1st paragraph, 2nd sentence reads '...
> 0.0025 ...' rather than '... 0.025 ..."
>
> -----Original Message-----
> From: Attila Beres [mailto:Attila.Beres(--nospam--at)Englekirk.com]
> Sent: Wednesday, May 24, 2000 5:26 PM
> To: Seaint Listserver posting
> Subject: UBC '97 Sec 1633.2.4 Deformation compatibilty
>
> If I am reading this right, this check asks for using the interstory
> deformation value to be considered as the greater of :
>
> 1. DeltaM, as calculated in accordance to Sec 1630.9.2 (0.7*R*DeltaS)
>
> 2. 0.025*story height.
>
> When would the first condition govern? The inelastic story drift ratios are
> limited to max. 0.025.
>
> Am I missing something, or the first condition is redundant?
> ...........................................................................
> Attila Beres
>
>
>