Seismic Risk Assessment of Reinforced Concrete Buildings Using Fuzzy Rule Based Modeling

Seismic resiliency of new buildings has improved over the years due to improved seismic codes and design practices. However, vulnerability of seismically deficient older buildings, designed and built on the basis of older codes of practice, poses a significant threat to life safety and survivability of buildings. It is economically not feasible to retrofit the entire seismically deficient infrastructure. Therefore, there is need for a comprehensive plan to identify critical structures and prioritize their retrofit requirements. Risk-based seismic assessment approach is proposed for prioritizing buildings for retrofit. Risk-base prioritization incorporates engineering decision making aspects, such as damage estimation, and societal value, tolerance to the consequence of failure. This is done by integrating site seismic hazard, building vulnerability, and importance/exposure factors. The complexity of building vulnerability assessment is handled through a systems theory where the complex problem is managed through hierarchical structure. The vagueness uncertainty encountered as a result of subjective walk down survey is handled through a fuzzy set theory. Fuzzy rule based modeling is used to incorporate decision maker’s attitude and intuitive knowledge in the aggregation process. The proposed method is illustrated through the use of May 1, 2003 Bingöl Earthquake damage observations. Results of the proposed risk-base prioritization method show good correlation with observed damage, albeit extracted from limited data sets.