Story-specific demand models and seismic fragility estimates for multi-story buildings

Abstract This paper develops seismic demand models for multi-story buildings. Story-specific demand models that consider the maximum interstory drift of each story are developed. Correlations among individual story demand models are also assessed to properly capture the potential dependence between maximum interstory drifts over the height of a building. Both linear and bilinear models in logarithmic space are considered to describe the relationships between drift demand and seismic intensity. A Bayesian approach is used to estimate the model parameters. The developed demand models are used to estimate the seismic fragility of two example buildings. The fragility estimates are compared with currently available estimates based on demand models for the overall maximum interstory drift. It is shown that when only the maximum interstory drift of a building is considered, the fragility might be underestimated; particularly if the interstory drifts for one or more stories are close to the maximum value. The proposed methodology provides a refined approach that includes more building response information than typical demand models, allowing for more accurate estimates of the seismic fragility of multi-story buildings.

[1]  Paolo Gardoni,et al.  Probabilistic Demand Models and Fragility Curves for Reinforced Concrete Frames , 2006 .

[2]  B. Ellingwood,et al.  Fragility assessment of building structural systems in Mid‐America , 2007 .

[3]  G. Atkinson,et al.  Ground-motion relations for eastern North America , 1995, Bulletin of the Seismological Society of America.

[4]  Henrik O. Madsen,et al.  Structural Reliability Methods , 1996 .

[5]  C. Allin Cornell,et al.  Probabilistic Basis for 2000 SAC Federal Emergency Management Agency Steel Moment Frame Guidelines , 2002 .

[6]  Paolo Gardoni,et al.  Seismic Fragility and Confidence Bounds for Gravity Load Designed Reinforced Concrete Frames of Varying Height , 2008 .

[7]  Jong Wha Bai.  Seismic fragility analysis and loss estimation for concrete structures , 2011 .

[8]  N. Null.  Seismic Rehabilitation of Existing Buildings , 2007 .

[9]  Bekir Özer AY,et al.  Vulnerability of Turkish Low-Rise and Mid-Rise Reinforced Concrete Frame Structures , 2008 .

[10]  Yi-Kwei Wen,et al.  Vulnerability Function Framework for Consequence-based Engineering , 2004 .

[11]  Marko Laine,et al.  Adaptive MCMC methods with applications in environmental and geophysical models , 2008 .

[12]  John W. Wallace,et al.  Seismic Design Criteria for Slab-Column Connections , 2007 .

[13]  Jong Wha Bai,et al.  Seismic retrofit of a reinforced concrete flat-slab structure: Part II — seismic fragility analysis , 2007 .

[14]  Armen Der Kiureghian,et al.  Probabilistic Capacity Models and Fragility Estimates for Reinforced Concrete Columns based on Experimental Observations , 2002 .

[15]  G. C. Tiao,et al.  Bayesian inference in statistical analysis , 1973 .

[16]  J. Bracci,et al.  Seismic Evaluation of Column-to-Beam Strength Ratiosin Reinforced Concrete Frames , 2001 .

[17]  John Geweke,et al.  Evaluating the accuracy of sampling-based approaches to the calculation of posterior moments , 1991 .

[18]  Jong Wha Bai,et al.  Seismic retrofit of a reinforced concrete flat-slab structure: Part I — seismic performance evaluation , 2007 .