Need a book? Engineering books recommendations...

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

Lack of Acceptable Cyclic Racking Shear Testing Protocol >> Major problems for Structural Innovation

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Fellow Engineers
    On June 6, 2007 I attended  the public hearing at the Los Angles International Code Council (ICC) Acceptance Criteria Evaluation >>
During the 3 day meeting several existing Acceptance Criteria agenda topics that involve shear wall assemblies. (AC04, AC15, AC130, AC154, AC269, AC 353, and AC 322)  I learned that many of the current Structural Response Modification Coefficients "R Factor"  have been based largely on judgment and qualitative comparisons of the known response capabilities of relative few types of lateral-force resisting systems that were widely used during late 1970's.  
    Today there are more than 70 individual structural systems, each having a somewhat arbitrarily assigned R-Factor.  We were informed that various research committees have been assigned to formalize a consistent procedure (FEMA ATC-63 {Applied Technology Council})  Since the various committee have not completed their research, the Los Angles ICC staff and board of directors voted to defer the use of all existing Acceptance Criteria's for high seismic and wind event regions and wait until the ATC 63 committee publishes their recommendations later this year.  
      During the hearing ICC staff explained that there are more than 600 affected current ICBO reports >> or ICC Legacy reports expire within 6 months >> and can not be renewed until there is a consensus among the ICC Staff , FEMA ATC -63 staff and the industries, including Sandwich panel, precast concrete panels, Foam Core Concrete Veneer, Insulated Concrete Form, Sips Panels, and Cold Formed Steel panels  & others >> These reports will not be renewed >> held for further study    
      Since California is preparing to adopt the IBC 2006 in January 2008 >> there is now and will be a great deal of pressure on the engineering community to have a consensus for a racking shear protocols  in high seismic and wind force areas throughout the United States. 
       I invite your comments >> We need to support the ICC and FEMA ATC-63 committee efforts >> However any significant delays will have a major affect on industry who have relied on the ICC Evaluation Reports to use their prosperity lateral force resistance assemblies in buildings with the blessing of city engineering plan checkers. It has been my experience that plan checker will not accommodate an outdated ICC Evaluation Report. 
Jim L. Chatterley PE
Composite Framing Systems, Inc.
2723 Currier Ave., Simi Valley, California, 93065
805-520-3666   Fax 805-583-1434