本研究根據國內幾棟中低層RC建築物(國家地震工程研究中心辦公大樓、中興大學土木環工大樓、台東縣消防局)在各個不同地震中,包括77地震、921地震、1022地震、614地震及0401地震所量測到之強震記錄輸入於以套裝軟體ETABS所建立建築物之數值模型,並進行動態歷時分析,而主要以求取建築物振動週期之第一模態為主,因此,將採用建築物頂層加速度(分析求得)與中央氣象局所提供之實測值進行比對,並修正建築物之梁柱勁度,用最小平方差找出最佳數學模型,模型中考慮是否包含地下室及是否設定土壤彈簧,最後,藉由修正建築物之梁柱勁度,找出最佳之阻尼比與振動週期,經輸入不同的地震歷時記錄,可看出受損前後梁柱勁度、阻尼比與振動週期之變化,以作為工程師在進行結構設計時的參考。 經本研究發現修正結構物梁柱之勁度,確實可以使分析模型更接近真實之反應,而結構物之振動週期與阻尼比在結構物受損前後,也可觀察出明顯的差異。
A parametric analysis on the structural behaviors of three low-to-midrise concrete buildings during past earthquakes was conducted in this study using the computer program ETABS. The stiffnesses and damping ratios of these structures as well as different modeling. Pechniques were examined to observe the sensitivity of the results to each individual factor. Comparisons were made primarily on roof accelerations obtained via structural analysis and those provided by the Central Weather Bureau. By adjusting the above parameters, an optimized structural model can be found for each building. In addition, the variation of element stiffness could be used as an index for structural damages.