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RE: www.seismicfactor.com <Warning!!>

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Casey,

This is another good reason why beta testing of any “software” becomes a high priority. The user assumes all responsibility that the results obtained are accurate based on their own knowledge of the code. Tables 11.6-1 and -2 are also contingent upon sections referenced in the footnotes of table 12.2-1 which will also kick in the requirements of the Overstrength Factor as well as the requirements for increased Rho values for redundancy when the distribution of base shear at a specific level (diaphragm) is less than 35% of the base shear.

This code is ambiguous at best and requires a solid understanding of the interlinking sections of code that are unique not only to building type and height but also by occupancy (residential 2-family or less).

The idea of beta testing helps those (even if limited to those within one company) to open discussions on these topics and to keep questioning what may not have seemed obvious from the start.

 

You raise a very good point and I don’t believe that name recognition is the only issue that points to accuracy of a tool – the user must be able to understand the codes sufficiently to continue to ask the questions. Personally, I would have preferred if the code writers released a logic flow chart that clearly guided the user of the code to the proper choices. Too much is left to interpretation or misinterpretation and this is slowing down the learning process for many of us.

Dennis

 

From: Casey K. Hemmatyar [mailto:khemmatyar(--nospam--at)gmail.com]
Sent: Friday, June 27, 2008 11:44 AM
To: seaint(--nospam--at)seaint.org
Subject: RE: www.seismicfactor.com <Warning!!>

 

Please be vary of using a design tool that someone else prepared!
 
The computation on the noted web site is substantially flawed and results in incorrect SDC determination.
The calculation completely disregards the requirements of Section 11.6 of ASCE and only uses Tables 11.6-1 & 11.6-2.

A few weeks ago I was reviewing a large DSA project. I spotted the similar wrong SDC determination. The designer had used an Excel spreadsheet prepared by a peer. The consequence was that the whole project has to be redesigned all over again.
Based on ASCE 7-05 Table 12.2-1, many of the Seismic Force-Resisting Systems are not permitted in SDC E & F!

 

Regards
Casey (Khashayar) Hemmatyar, SE


 

dateFri, Mar 28, 2008 at 1:20 PM
subjectwww.seismicfactor.com

hide details Mar 28 Reply


Has anyone tried www.seismicfactor.com? Pretty neat.
 
Bill