Increased Accuracy of Vector-IM-Based Seismic Risk Assessment?

The vector-valued ground motion intensity measure (IM) consisting of spectral acceleration at two different periods is considered for seismic risk assessment of structures. The first component of the IM is the spectral acceleration at the first-mode structural period T 1. The second period is selected to increase efficiency in the estimation of seismic risk (i.e., minimizing dispersion). A method to assess vector structural fragility using a scalar global measure of structural performance is proposed. With reference to an example RC frame structure, the accuracy of prediction of the seismic risk using the considered vector IM vs. a conventional scalar IM is presented. In both cases, probabilistic seismic hazard analysis (scalar and vector) is carried out by means of a subset simulation approach that employs a stochastic model of ground motion. Results show that an effective choice of the second period T2 leads to an estimate of the seismic risk close to that obtained employing the scalar IM consisting of Sa(T1) only, while reducing the associated dispersion in the estimate. For the examined example structure, however, the reduction is negligible in light of the effort required for switching from a scalar to a vector IM.

[1]  James L. Beck,et al.  SUBSET SIMULATION AND ITS APPLICATION TO SEISMIC RISK BASED ON DYNAMIC ANALYSIS , 2003 .

[2]  M. Fardis,et al.  Deformations of Reinforced Concrete Members at Yielding and Ultimate , 2001 .

[3]  Fatemeh Jalayer,et al.  Direct probabilistic seismic analysis: Implementing non-linear dynamic assessments , 2003 .

[4]  M. Kenward,et al.  An Introduction to the Bootstrap , 2007 .

[5]  Paolo Bazzurro,et al.  Vector-valued Probabilistic Seismic Hazard Analysis (VPSHA) , 2002 .

[6]  W. Silva,et al.  Stochastic Modeling of California Ground Motions , 2000 .

[7]  J. Baker,et al.  A vector‐valued ground motion intensity measure consisting of spectral acceleration and epsilon , 2005 .

[8]  Nicolas Luco,et al.  Probabilistic seismic demand analysis using advanced ground motion intensity measures , 2007 .

[9]  C. Cornell,et al.  Correlation of Response Spectral Values for Multicomponent Ground Motions , 2006 .

[10]  J. Baker,et al.  Spectral shape, epsilon and record selection , 2006 .

[11]  R. Musson.  DETERMINATION OF DESIGN EARTHQUAKES IN SEISMIC HAZARD ANALYSIS THROUGH MONTE CARLO SIMULATION , 1999 .

[12]  N. Abrahamson,et al.  Empirical Response Spectral Attenuation Relations for Shallow Crustal Earthquakes , 1997 .

[13]  C. Allin Cornell,et al.  Probabilistic seismic demand analysis of nonlinear structures , 1999 .

[14]  Fatemeh Jalayer,et al.  Seismic hazard analysis for alternative measures of ground motion intensity employing stochastic simulation methods , 2007 .

[15]  C. Allin Cornell,et al.  Structural Seismic Demand Analysis: Consideration of "Collapse" , 2000 .

[16]  R. Mcguire.  Probabilistic seismic hazard analysis and design earthquakes: Closing the loop , 1995, Bulletin of the Seismological Society of America.

[17]  J. Beck,et al.  Estimation of Small Failure Probabilities in High Dimensions by Subset Simulation , 2001 .

[18]  Dimitrios Vamvatsikos,et al.  Developing efficient scalar and vector intensity measures for IDA capacity estimation by incorporating elastic spectral shape information , 2005 .

[19]  Fatemeh Jalayer,et al.  A scalar damage measure for seismic reliability analysis of RC frames , 2007 .

[20]  Dimitrios Vamvatsikos,et al.  Incremental dynamic analysis , 2002 .

[21]  C. Cornell,et al.  Vector-valued Intensity Measures Incorporating Spectral Shape For Prediction of Structural Response , 2008 .