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RE: UBC '97 Sec 1633.2.4 Deformation compatibility

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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