In the U.S., seismic building provisions are initially developed by the National Institute of Building Sciences (NIBS) through their Building Seismic Safety Council (BSSC). The Provision Update Committee (PUC) within BSSC develops the draft National Earthquake Hazards Reduction Program (NEHRP) provisions. The NEHRP provisions are used as the starting point for all updates ultimately completed by ASCE 7. SDII contributed to the 2022 updates within extensive improvements for concrete-filled steel deck floor diaphragms and bare steel deck roof diaphragms. Now with the 2026 cycle underway SDII researchers are again providing assistance to the BSSC PUC. From the NIBS website:
“The NEHRP Recommended Provisions for New Buildings and Other Structures embodies the state–of–knowledge criteria for the design and construction of buildings subject to earthquake hazards. The techniques and technologies contained in this resource document are diffused into several national standards, including the American Society of Civil Engineers ASCE–7 Design Standard for Minimum Loads that are referenced by the model building codes developed by the International Code Council (ICC). The Provisions are developed by the Provisions Update Committee (PUC), a technical committee of seismic experts that identify and apply the most advanced seismic technology available. The committee is supported by expert Issue Teams (ITs) that address specific aspects of seismic design methodology and construction. These committee and team members ensure that lessons learned from the building performance during the earthquakes, as well as new research to improve earthquake resistance, are reflected in state–of–the–art seismic requirements. The ITs develop proposals for requirements that are balloted by the PUC according to BSSC’s consensus process, and subsequently balloted by its Professional Organizations (POs).”
TOPIC #8: UNIFICATION OF DIAPHRAGM DESIGN PROVISIONS
The SDII team are working specifically on Topic #8 in the BSSC PUC: Unification of Diaphragm Design Provisions. Again from the NIBS website “This Issue Team will bring to culmination work that was started in the 2015 NEHRP Provisions cycle and continued through the 2020 NEHRP Provisions cycle.
- Develop diaphragm design force reduction factors, overstrength factors, and deflection amplification factors for additional diaphragm types.
- Unify treatment of special seismic detailing for bare steel deck diaphragms
- Unify the diaphragm design provisions of Sections 12.10.3 and 12.10.4.
- Permit the traditional design method of Section 12.10.1 only for the design of diaphragm types for which diaphragm force reduction factors are not available.
- Additionally, evaluate whether it is of benefit to develop a code formula for period for structures with flexible diaphragms, to allow design engineers to better estimate force levels before applying an R-factor. This is already implemented in the Canadian code.
- Investigate the issue of strut stiffness effects on the load path.”
| NAME | AFFILIATION | Role |
|---|---|---|
| S. K. Ghosh | S. K. Ghosh Associates LLC | Chair |
| Kelly Cobeen | Wiss, Janney, Elstner Associates, Inc | Vice Chair |
| Nick Blanchette | ZFA Consulting | Voting Member |
| Matthew Eatherton | Virginia Tech | Voting Member |
| Ron LaPlante | Division of the State Architect | Voting Member |
| John Lawson | Architectural Engineering Cal Poly | Voting Member |
| David McCormick | Simpson Gumpertz & Heger | Voting Member |
| Thomas Meyer | Magnusson Klemencic Associates, Seattle | Voting Member |
| Ben Schaeffer | Johns Hopkins, Baltimore, MD | Voting Member |
| Christina Aronson | Federal Emergency Management Agency | Corresponding Member |
| Pat Bodwell | Verco Deck | Corresponding Member |
| Scott Breneman | WoodWorks – Wood Products Council | Corresponding Member |
| Jared E. Brewe | Precast/Prestressed Concrete Institute | Corresponding Member |
| J. Daniel Dolan | Washington State University | Corresponding Member |
| Ngai-Chi Chung | Berkshire Hathaway Specialty Insurance | Corresponding Member |
| Jeff Dragovich | DeSimone Consulting Engineers | Corresponding Member |
| Erica C. Fischer | School of Civil and Construction Engineering Oregon State University | Corresponding Member |
| John M. Hochwalt | KPFF Consulting Engineers | Corresponding Member |
| Ihsan Keckin | Bogazici University | Corresponding Member |
| Brian Kehoe Wiss | Janney, Elstner Associates, Inc. | Corresponding Member |
| Dominic J. Kelly | Simpson Gumpertz & Heger | Corresponding Member |
| Dawn Lehman | University of Washington | Corresponding Member |
| Philip Line | American Wood Council | Corresponding Member |
| Mahsa Mahdavian | ASC Steel Deck | Corresponding Member |
| Bonnie Manley | American Iron and Steel Institute | Corresponding Member |
| Dion Marriott | Holmes Structures | Corresponding Member |
| Andrew W. Taylor | KPFF Consulting Engineers | Corresponding Member |
| Mai (Mike) Tong | Federal Emergency Management Agency | Corresponding Member |
| Shahab Torabian | Simpson Gumpertz & Heger | Corresponding Member |
| Robert Tremblay | Corresponding Member | |
| Alex W. Wilson, PE | Magnusson Klemencic Associates | awilson@mka.com |
| John Hooper | MKA | PUC Chair |
| Jiqiu Yuan | NIBS | BSSC Executive Director |
| Roberto Leon | Virginia Tech | BSSC Board Liaison |