The BSSC Board, PUC Meet in Washington, D.C.

The Provisions Update Committee (PUC) of the Building Seismic Safety Council (BSSC) met January 7-8 in Washington, D.C., during Building Innovation 2014, to continue assessing proposals to update the National Earthquake Hazards Reduction Program’s (NEHRP) 2009 NEHRP Recommended Seismic Provisions for New Buildings and Other Structures, and specifically to assess the results of Ballot E.

Following the two-day PUC meeting, the BSSC Board of Direction met January 9, and voted to ballot passed items in PUC Ballot E, and earlier Ballots C and D, in Membership Organization (MO) Ballot No. 2. The 50 BSSC member organizations that represent the building industry will begin their assessment of MO Ballot No. 2 this month. Previously, the Board also accepted MO Ballot No. 1, which will be included in the 2015 NEHPR Recommended Seismic Provisions. Membership Ballot No. 1 addresses adoption of ASCE 7-10, its Supplemental No. 1 and Commentary, Chapter 24 on simplified provisions, and Chapter 22 on seismic maps for Guam and American Samoa.

PUC Ballot E is the fifth ballot to be assessed by the PUC in the five-year cycle for the development of the 2015 Provisions. PUC Ballot F, to follow, will be the sixth and last opportunity for the PUC to develop and assess proposals that will form the three parts of the Provisions. It includes: proposed changes to ASCE7-10 Minimum Design Loads for Buildings and Other Structures (Part 1); changes to the ASCE7-10 Commentary (Part 2); and resource papers on special topic in seismic design (Part 3). In PUC Ballot E, 24 proposals were balloted, of which 18 passed and six failed. Proposals that passed address changes to the following Chapters in ASCE 7-10 that are intended to be included in Parts 1 and 2 of the Provisions depending on the outcome of MO Ballot No. 2:

Chapters 11 & 12 Diaphragm Design Force Level
Chapter 12

Foundations on Liquefiable Sites
Accidental Torsion
Vertical Seismic Load Effect
Scaling Design Values
Structural Modeling
Combined Response
Number of Modes
Linear Modal Response
Simplified Design Procedure for Bearing Wall or Building Frame Systems

Chapter 17 - Seismically Isolated Structures

Residual Displacement
Steel Concentric Braced Frames

Chapter 18 - Structures with Damping Systems
Chapter 19 - Soil-Structure Interaction

Five of the six proposals that failed in Ballot E are expected to be redrafted and resubmitted as part of Ballot F to go out to the PUC for evaluation this month. One of the proposals will be further developed in the next five-year cycle of the Provisions. The results of F, along with MO Ballot No. 2, will be assessed at a PUC meeting to be held May 7-8, 2014 in Burlingame, California.

The results of these ballots will be passed onto the BSSC Board of Direction for affirmation. Approved MO Ballot No. 2 proposals will be incorporated into the 2015 Provisions. Approved Ballot F proposals will go into MO Ballot No. 3.