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Title |
Collapse Capacity Evaluation of Steel Intermediate Moment Frames Using Incremental Dynamic Analysis
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Keywords |
철골 중간모멘트골조 ; 내진성능 ; 증분동적해석 ; 붕괴여유비 ; 붕괴확률 ; 이력형 에너지 소산장치 Steel intermediate moment frame(IMF) ; Seismic performance ; Incremental dynamic analysis ; Collapse margin ratio(CMR) ; Collapse probability ; hysteretic energy dissipating device(HEDDs) |
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Abstract |
Steel intermediate moment frames (IMFs) have been generally used as seismic load resisting systems (SLRSs) of a building to provide resistances against strong ground shaking. However, most of low and mid-rise steel buildings in Korea were constructed during pre-seismic code era or before the introduction of well-organized current seismic codes. It has been recognized that the seismic performance of these steel IMFs is still questionable. In order to respond to such a question, this study quantitatively investigates the seismic capacities of steel IMFs. Prototype models are built according to the number of stories, the levels of elastic seismic design base shear and the ductilities of structural components. Also, the other prototype models employing hysteretic energy dissipating devices (HEDDs) are considered. The collapse mechanism and the seismic performance of the prototype models are then described based on the results obtained from nonlinear-static and incremental-dynamic analyses. The seismic performance of the prototype models is assessed from collapse margin ratio (CMR) and collapse probability. From the assessment, the prototype model representing new steel IMFs has enough seismic capacities while, the prototype models representing existing steel IMFs provide higher collapse probabilities. From the analytic results of the prototype models retrofitted with HEDDs, the HEDDs enhance the seismic performance and collapse capacity of the existing steel IMFs. This is due to the energy dissipating capacity of the HEDDs and the redistribution of plastic hinges.
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