Summary: | 碩士 === 國立臺灣大學 === 土木工程學研究所 === 101 === The ATC-58 project in the United States developed and published next-generation tools and procedures for seismic performance assessment of buildings in 2012. In the ATC-58 procedures, damage is measured in terms of direct economic loss, indirect economic loss and casualties rather than by building component deformations and accelerations. Uncertainty and randomness will be captured in every step of the performance assessment process, including characterization of earthquake hazard, simulation of building response, damage assessment, and loss computation.
The ATC-58 procedures offer three different types of assessments, namely, intensity-, scenario- and time-based assessments. All three involve the use of response-history analysis. The objective of this study is to develop recommendations for the selection and scaling of ground motions for scenario-based assessment. The scenario-based assessment aims at predicting the loss for a specific scenario (representing by a combination of earthquake magnitude and distance). The ground motions scaled for the assessment should reflect the distribution of spectral acceleration for the specific scenario.
In this study, a series of nonlinear response-history analyses were performed for a 15-story and a 5-story sample moment resisting frames subjected to ground motions scaled for three sample earthquake scenarios determined based on the aggregation data for the site of the sample buildings.Sets of ground motions were developed for each building and each earthquake scenario using three scaling methods, namely, Conditional Spectrum Method, Unconditional Spectrum Method and Distribution Scaling Method. The impact of 1) scaling procedures, 2) number of ground motions, and 3) ground-motion database on structure responses, including peak inter-story drift, peak floor acceleration, and floor spectral acceleration, was studied. Recommendations for ground-motion scaling procedures for ATC-58 scenario-based assessment were developed.Selections of 30 ground motions from scenario database for ground-motion scaling procedures(Unconditional Spectrum Method and Distribution Scaling Method) is recommended in this study.
|