The American Society of Civil Engineers (ASCE) recently updated its guidelines for retrofits in earthquake-prone areas. The ASCE/Structural Engineering Institute (SEI) 41-17, Seismic Evaluation and Retrofit of Existing Buildings, describes deficiency-based and systematic procedures to evaluate and retrofit existing buildings to withstand the effects of earthquakes.
The latest edition has revised the basic performance objectives for existing buildings and evaluation of force-controlled actions. A three-tiered process is presented for seismic evaluation according to a range of building performance levels. The deficiency-based procedures allow evaluation and retrofit efforts to focus on potential deficiencies for a specified set of building types and heights. The systematic procedure sets forth a methodology to evaluate the entire structure in a rigorous manner.
Analysis procedures and acceptance criteria are established, and requirements specified for:
- foundations and geologic site hazards;
- building components; and
- seismic isolation and energy dissipation systems.
This standard is a primary reference for structural engineers addressing the seismic resilience of existing buildings, and for building code officials reviewing such work. It also will be of interest to architects, construction managers, academic researchers, and building owners.