Comparing vector-valued intensity measures for fragility analysis of steel frames in the case of narrow-band ground motions

2012 ◽  
Vol 45 ◽  
pp. 472-480 ◽  
Author(s):  
Edén Bojórquez ◽  
Iunio Iervolino ◽  
Alfredo Reyes-Salazar ◽  
Sonia E. Ruiz
Keyword(s):  
Narrow Band ◽  
Ground Motions ◽  
Steel Frames ◽  
Fragility Analysis ◽  
Intensity Measures ◽  
Vector Valued

On the Use of Vector-Valued Intensity Measure to Predict Peak and Cumulative Demands of Steel Frames under Narrow-Band Motions

2014 ◽  
Vol 595 ◽  
pp. 137-142 ◽  
Author(s):  
Edén Bojórquez ◽  
Alfredo Reyes-Salazar ◽  
Sonia E. Ruiz
Keyword(s):  
Narrow Band ◽  
Ground Motions ◽  
Steel Frames ◽  
Spectral Shape ◽  
Intensity Measure ◽  
Intensity Measures ◽  
Energy Demands ◽  
Long Duration ◽  
Story Drift ◽  
Vector Valued

In this study, various alternative vector-valued ground motion intensity measures (IMs) are used to estimate maximum inter-story drifts and hysteretic energy demands of steel framed buildings under long duration narrow-band ground motions. The vectors are based on the spectral acceleration at first mode of the structure as first parameterSa (T1). As the second parameter of the vector,IMsrelated to peak, integral and spectral shape parameters are selected. It is concluded that spectral-shape-based vector-valuedIMshave the best relation with maximum inter-story drift and energy demands in steel frames subjected to narrow-band earthquake ground motions.

scholarly journals Vector-Valued Fragility Analysis Using PGA and PGV Simultaneously as Ground-Motion Intensity Measures

2010 ◽  
Vol 5 (4) ◽  
pp. 407-416
Author(s):  
Sei’ichiro Fukushima ◽  
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Analysis ◽  
Fragility Curves ◽  
Fragility Analysis ◽  
Peak Ground Velocity ◽  
Seismic Risk Analysis ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Vector Valued

Seismic risk analysis usually expresses ground-motion intensity using a single index such as peak ground acceleration (PGA), spectral acceleration for a specified period, or peak ground velocity (PGV). Limiting the number of indices, however, adds greater uncertainty when estimating annual failure probability given by convolving seismic hazard and fragility curves. This is because information other than ground-motion intensity is missing. Author proposed seismic hazard analysis using PGA and PGV simultaneously as groundmotion input measures. After analyzing the correlation coefficient between PGA and PGV using K-NET and KiK-net databases, probabilistic seismic hazard for seven sites in Kanto district in Japan was evaluated. In this study, seismic fragility analysis using PGA and PGV is conducted followed by advantage of vector-valued fragility analysis.

Comparison of steel frames with RWS and WFP beam-to-column connections through seismic fragility analysis

2020 ◽  
pp. 136943322097728
Author(s):  
Haoran Yu ◽  
Weibin Li
Keyword(s):  
Limit State ◽  
Pushover Analysis ◽  
Steel Frames ◽  
Fragility Analysis ◽  
Structural Safety ◽  
Seismic Fragility ◽  
Fe Modelling ◽  
Collapse Resistance ◽  
Seismic Collapse ◽  
Probabilistic Seismic Demand

Reduced web section (RWS) connections and welded flange plate (WFP) connections can both effectively improve the seismic performance of a structure by moving plastic hinges to a predetermined location away from the column face. In this paper, two kinds of steel frames—with RWS connections and WFP connections—as well as different frames with welded unreinforced flange connections were studied through seismic fragility analysis. The numerical simulation was conducted by using multiscale FE modelling. Based on the incremental dynamic analysis and pushover analysis methods, probabilistic seismic demand analysis and seismic capability analysis were carried out, respectively. Finally, combined with the above analysis results, probabilistic seismic fragility analysis was conducted on the frame models. The results showed that the RWS connection and WFP connection (without double plates) have little influence on reducing the maximum inter-storey drift ratio under earthquake action. RWS connections slightly reduce the seismic capability in non-collapse stages and improve the seismic collapse resistance of a structure, which exhibits good structural ductility. WFP connections can comprehensively improve the seismic capability of a structure, but the seismic collapse resistance is worse than that of RWS connections when the structure has a large number of storeys. The frame with WFP connections has a lower failure probability at every seismic limit state, while the frame with RWS connections sacrifices some of its structural safety in non-collapse stages to reduce the collapse probability.

scholarly journals Seismic Fragility Analysis of Mid-Story Isolation Buildings

2021 ◽  
Keyword(s):  
Fragility Curves ◽  
Ground Motions ◽  
Near Field ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Plastic State ◽  
Far Field ◽  
Analysis Method ◽  
Isolation System ◽  
Isolation Layer

Abstract. Seismic fragility analysis is essential for seismic risk assessment of structures. This study focuses on the damage probability assessment of the mid-story isolation buildings with different locations of the isolation system. To this end, the performance-based fragility analysis method of the mid-story isolation system is proposed, adopting the maximum story drifts of structures above and below the isolation layer and displacement of the isolation layer as performance indicators. Then, the entire process of the mid-story isolation system, from the initial elastic state to the elastic-plastic state, then to the limit state, is simulated on the basis of the incremental dynamic analysis method. Seismic fragility curves are obtained for mid-story isolation buildings with different locations of the isolation layer, each with fragility curves for near-field and far-field ground motions, respectively. The results indicate that the seismic fragility probability subjected to the near-field ground motions is much greater than those subjected to the far-field ground motions. In addition, with the increase of the location of the isolation layer, the dominant components for the failure of mid-story isolated structures change from superstructure and isolation system to substructure and isolation system.

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