Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

UBC97 question

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I am forwarding this query for discussion.

	To Whom It May Concern:  

"My name is Michael Kingsmore and I work in the Structural Engineering
Department at Sherlock, Smith and Adams, Inc. (an A/E firm) in Montgomery,
Alabama.  Most of our work is done for the Department of Defense -
specifically medical facilities for the  DOD.  

"Generally, when our firm encounters projects where seismic analysis is
necessary, we consult with firms specializing in seismic design.
However, we are interested in doing seismic analysis in house and are in the
process of performing our own dynamic analysis on a current project.  

"The governing code for the project is UBC 97.  Our current frame design
software is capable of Static Force Procedure and Dynamic Analysis
(utilizing UBC Normalized Response Spectra, NEHRP Normalized Response
Spectra or El-Centro Response Spectra).  I am having trouble understanding
why there is such a huge difference in member forces and
displacements/drifts between the results obtained using the Static Force
Procedure and results obtained using the Dynamic Analysis.  The Dynamic
Analysis results are much higher than those obtained through the Static
Force Procedure (typically 3 times larger).  It would seem to me that the
static approximation would be much more conservative than the dynamic

"I would appreciate any information or thoughts that would shed some light
on this dilemma.  Thank you for your time.  

Michael A. Kingsmore  
e-mail:  kingsmore_m(--nospam--at)  
Structural Department  
Sherlock, Smith and Adams, Inc.  
3047 Carter Hill Road  
Montgomery, AL   36111-0006  
(334) 263-6481  
FAX: (334) 264-4509  

Ken Wong			Tel: 510-231-9564
PEER Bldg. 451 RFS		Fax: 510-231-9461
1301 South 46th Street     E-mail: info(--nospam--at)
Richmond, CA  94804-4698