其他摘要：Puerto Rico is situated in an earthquake prone region. Because of the imminent risk of being affected by a strong earthquake, it is important to study the damage vulnerability of existing structures in the Island. This study is directed to medium rise concrete residential buildings in Puerto Rico. Most of multistory residential buildings in Puerto Rico are reinforced concrete structures with lateral resisting system composed by shear walls oriented in both directions. The lack of local earthquake vulnerability curves for Puerto Rico and the fact that local construction practice differs from that in USA motivates the author to look at the development of reliable fragilities curves based on typical buildings properties and selection of ground motions based on local geology characteristics and past worldwide earthquakes scaled to different peak ground acceleration to obtain a wide range of maximum accelerations. The analytical models are two-dimensional and are analyzed using the nonlinear dynamic time history method considering both flexural and shear nonlinear behavior for shear walls. Algan’s formulation (1982) and HAZUS drift limits were used to calculate the expected damage of the models. Damage of the structures is quantified based on the inter-story drift ratio of the structure. The damage states considered were: Minor, Moderate, Substantial and Major, for Algan and Slight, Moderate, Extensive and Complete for Hazus. With this information, lognormal functions expressed in the form of two parameters (log-median and log-standard deviation) were fitted and fragility curves developed as a function of PGA. A set of four fragility curves, one for each damage state is developed for each scenario studied. These curves are useful tools for the insurance companies in Puerto Rico in order to improve their risk assessments.
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