Procedures for Post Earthquake Safety Evaluation of Buildings & Addendum

The ATC-20 Set consists of two documents: the ATC-20 report, Procedures for Postearthquake Safety Evaluation of Buildings, and the ATC-20-2 Report, Addendum to the ATC-20 Postearthquake Building Safety Evaluation Procedures. The ATC-20 report was developed under a contract from the California Office of Emergency Services (OES), California Office of Statewide Health Planning and Development (OSHPD) and FEMA. (Published 1989, 152 pages). The ATC-20-2 Addendum, developed under a grant from the National Science Foundation (NSF), with funding provided by the U. S. Geological Survey (USGS), contains revised placards and safety assessment forms, based on ATC-20 use following the 1989 Loma Prieta, 1992 Cape Mendocino, 1992 Landers, 1992 Big Bear, and 1994 Northridge earthquakes (Published 1995, 94 pages).

ATC-20 ABSTRACT: Introduced two weeks prior to the 1989 Loma Prieta earthquake, the ATC-20 report provides procedures and guidelines for making on-the-spot evaluations and decisions regarding continued use and occupancy of earthquake damaged buildings. Written specifically for volunteer structural engineers and building inspectors, the report has become the de-facto national standard for safety evaluation of earthquake-damaged buildings. The report includes rapid and detailed evaluation procedures for inspecting buildings and posting them as INSPECTED (apparently safe, green placard), LIMITED ENTRY (yellow placard) or UNSAFE (red placard). Also included are special procedures for evaluation of essential buildings (e.g., hospitals), evaluation procedures for nonstructural elements and geo-technical hazards, and guidance on human behavior following earthquakes.

ATC-20-2 ABSTRACT: The ATC-20-2 Addendum report provides updated assessment forms, placards, and procedures that are based on an in-depth review and evaluation of the widespread application of the ATC-20 procedures following five earthquakes occurring since the initial release of the ATC-20 report in 1989. One of the principal recommendations is the replacement of the yellow LIMITED ENTRY posting placard with a revised yellow placard entitled, RESTRICTED USE. Also included are procedures for conducting initial wind-shield surveys of damaged areas, guidance on estimating the cost to repair earthquake damage, and updated guidance on human behavior following natural disasters, including a concise handout for owners and occupants of damaged buildings.