| Steel and Composite Structures Volume 9, Number 5, October 2009, pages 457-471 DOI: http://dx.doi.org/10.12989/scs.2009.9.5.457 | |
Role of accidental torsion in seismic reliability
assessment for steel buildings | |
Heui-Yung Chang, Chu-Chieh Jay Lin, Ker-Chun Lin and Jung-Yu Chen
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| Abstract [Full Text] | |
| This study investigates the role of accidental torsion in seismic reliability assessment. The analyzed structures are regular 6-story and 20-story steel office buildings. The eccentricity in a floor plan was simulated by shifting the mass from the centroid by 5% of the dimension normal to earthquake shaking. The eccentricity along building heights was replicated by Latin hypercube sampling. The fragilities for immediate occupancy and life safety were evaluated using 0.7% and 2.5% inter-story drift limits. Two limit-state probabilities and the corresponding earthquake intensities were compared. The effect of ignoring accidental torsion and the use of code accidental eccentricity were also assessed. The results show that accidental torsion may influence differently the structural reliability and limit-state PGAs. In terms of structural reliability, significant differences in the probability of failure are obtained depending on whether accidental torsion is considered or not. In terms of limit-state PGAs, accidental torsion does not have a significant effect. In detail, ignoring accidental torsion leads to underestimates in low-rise buildings and at small drift limits. On the other hand, the use of code accidental eccentricity gives conservative estimates, especially in high-rise buildings at small drift limits. | |
| Key Words | |
| seismic performance; reliability-based assessment; fragility analysis; accidental torsion; mass eccentricity; steel buildings. | |
| Address | |
| Heui-Yung Chang; Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Kaohsiung, 81148, Taiwan Chu-Chieh Jay Lin; National Center for Research on Earthquake Engineering, National Applied Research Laboratories, No.200 Sec.3, ShinHai Rd., Taipei, 10668, Taiwan Ker-Chun Lin; National Center for Research on Earthquake Engineering, National Applied Research Laboratories, No.200 Sec.3, ShinHai Rd., Taipei, 10668, Taiwan Jung-Yu Chen; Department of Civil and Environmental Engineering, National University of Kaohsiung, No. 700, Kaohsiung University Rd., Kaohsiung, 81148, Taiwan | |
