NEHRP Clearinghouse

Reliability of Existing Buildings in Earthquake Zones.
Yao, J. T. P.
National Science Foundation, Washington, DC. Engineering and Applied Science., December 1979, 55 p.
Identifying Number(s)
Results are reported of a research project designed to formulate reliability criteria and to analyze available test data for the safety evaluation of complex existing structures. A literature review was conducted in three areas: (1) system identification involving techniques developed to obtain a mathematical representation of a specific physical system when both input and output are known, (2) damage assessment of existing structures, and (3) structural identification with respect to damage and reliability functions and equations of motion. Formulation of reliability evaluation is discussed with respect to damage function, application of pattern recognition, and application of fuzzy sets. Preliminary analysis of available test data is described whereby two simple methods identified linear parameters as a function of a strong-motion earthquake in San Fernando's 42-story Union Bank which sustained minor damage during the 1971 earthquake. Results indicate that although the linear and slightly nonlinear behavior of structures can be successfully analyzed mathematically, the analysis of structures through various stages of damaging loading conditions remains unsolved. Hence, classification and identification of damage states for complex systems require further study.
Reliability; Dynamic response; Fuzzy sets; Buildings; Earthquake resistant structures; Damage assessment; Risk analysis; Seismic design; Structural design; Earthquakes; Mathematical models; Dynamic structural analysis