BSSC Provisions Update Committee Assesses Ballot D

In the five-year cycle for the development of the 2014 NEHPR Recommended Seismic Provisions there are six ballots, A through F, through which members of the Provisions Update Committee (PUC) of the Building Seismic Safety Council (BSSC) develop and assess proposals that will form the three parts of the Provisions. These are: proposed changes to ASCE 7-10 Minimum Design Loads for Buildings and Other Structures (Part 1), changes to the ASCE 7-10 Commentary (Part 2), and resource papers on special topic in seismic design (Part 3).

The PUC met in Burlingame, Calif., on September 24–25 to assess the results of Ballot D. Fifteen proposals were balloted, twelve passed and three failed. Proposals that passed addressed changes to Parts 1 and 2 of the Provisions:

• Maps and values for uniform-hazard and deterministic ground motions
• Coefficients and parameters that define ground motion intensity
• Revision of the seismic response procedures based on developments in performance-based design
• Limiting the use of the equivalent lateral force procedure to buildings that that have been observed to behave acceptably in major seismic events

A Part 3 resource paper also was approved that addresses the ATC-84 Project: Improved Seismic Performance Factors for Design of New Buildings.

The three proposals that failed in Ballot D will be redrafted and resubmitted as part of Ballot E to go out to the PUC for evaluation in mid-October. The results of E will be assessed at a PUC meeting to be held January 7–8, 2014, in Washington, D.C., as part of the Building Innovation 2014: The National Institute of Building Sciences Annual Conference and Expo, running January 6–10.

The Building Seismic Council’s combined Board of Direction and Annual meetings will follow the PUC meeting on January 9 during Building Innovation 2014. Here proposals for PUC Ballots C, D and E will be reviewed for inclusion in the ballot that will go to the 51 BSSC member organizations that represent the building industry in mid-January. In May, the results of this ballot will be reviewed by the PUC and passed onto the BSSC Board of Direction for affirmation. Approved proposals will be incorporated into the 2014 Provisions.