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97 UBC Drift: ASD vs Strength Design

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I have a question regarding the determination of the Design Level Response
drift, delta-s.

The May '98 Errata to the UBC appears to allow delta-s to be calculated at
Allowable Stress level forces when using ASD.  Section 1630.9.1 states:

"A static, elastic analysis of the lateral force-resisting system shall be
prepared using the design seismic forces from Section 1630.2.1....  Where
Allowable Stress Design is used and where drift is being computed, the load
combinations of Section 1612.2 (changed to 1612.3 per May '98 errata) shall
be used."

The load combinations of 1612.3 use E/1.4.  Therefore, it appears that the
delta-s for Allowable Stress Design will be lower than for Strength Design.
Since neither delta-m, nor the story drift limits of section 1630.10
differentiate between ASD and Strength Design, it appears that drift
requirements will be easier to satisfy using ASD.

Does anyone have any insight into this apparent disconnect?  (Or does the
ASD club score one point over the LRFD club?....)  If this thread has
already been discussed, please let me know.  Thanks.

Mark H. Larsen, P.E.
Phoenix, Arizona