Structural Engineering Advisory Committee

Office to Residential conversions and seismic upgrade options

Address outstanding issues from previous meeting:

• Under Alternate Seismic Improvement standard option A: For single story buildings, only items under Basic Structural Checklist from ASCE 41 (excluding foundation and pounding) are required to be evaluated and mitigated. For Single Story URM buildings, should a check for out of plane using h/t ratios of the Tier 1 checklist be required in addition to the Basic Structural Checklist requirements?
• Under Alternate option A, what are the seismic upgrade requirements for single story buildings in High or Very High Liquefaction zones?
• Alternate Option B: Bolts Plus type of seismic upgrade
  Determine the seismic improvement standard and the ground motions to use for this standard. See proposed criteria for URM buildings that were considered as part of the previous City efforts to mandate URM retrofits.
• Verify seismic improvement standard under alternate option "B" for concrete buildings.  Only items under Basic Structural Checklist from ASCE 41 (excluding foundation and pounding) are required to be evaluated and mitigated plus check for adequacy of concrete columns to sustain drift without collapse All concrete building types (C1,C2,C3, PC1,PC2?) or limit to Concrete Moment Frames only (C1)?
• For non-structural items what is the ground motions and improvement standard for Option "A" and option "B"?