The performance of multi-span steel-concrete composite bridges in recent seismic events has shown that these structures are very sensitive to earthquake loading. Following the Performance-Based Earthquake Engineering (PBEE) framework, the vulnerability assessment of these systems must take rigorously into account all pertinent sources of uncertainty, including uncertainties in the loading and in the structural/mechanical/geometrical properties (model parameter uncertainty). The model parameter uncertainty affects not only the structural capacity, but also the Engineering Demand Parameters (EDPs). However, most of the procedures for fragility calculation focus on the variability of EDPs due to input ground motion uncertainty (record-to-record variability) and neglect model parameter uncertainty effects, or incorporate these effects only in a simplified way. This paper aims at studying the effects of model parameter uncertainty on the seismic response and on the seismic vulnerability of steel-concrete composite bridges with abutment transverse restraints. In this paper, the Extended Incremental Dynamic Analysis (EIDA) method is used to account for all sources of aleatoric uncertainty. EIDA is applied to a benchmark SCC bridge system with dual load path to estimate the first- and second-order statistics of the EDPs of interest, to assess the sensitivity of the structural response to the model parameter uncertainty, and to evaluate the seismic vulnerability accounting for all pertinent sources of uncertainty.
Influence of model parameter uncertainties on the seismic vulnerability analysis of continuous steel-concrete composite bridges exhibiting dual-load paths
DALL'ASTA, Andrea
2010-01-01
Abstract
The performance of multi-span steel-concrete composite bridges in recent seismic events has shown that these structures are very sensitive to earthquake loading. Following the Performance-Based Earthquake Engineering (PBEE) framework, the vulnerability assessment of these systems must take rigorously into account all pertinent sources of uncertainty, including uncertainties in the loading and in the structural/mechanical/geometrical properties (model parameter uncertainty). The model parameter uncertainty affects not only the structural capacity, but also the Engineering Demand Parameters (EDPs). However, most of the procedures for fragility calculation focus on the variability of EDPs due to input ground motion uncertainty (record-to-record variability) and neglect model parameter uncertainty effects, or incorporate these effects only in a simplified way. This paper aims at studying the effects of model parameter uncertainty on the seismic response and on the seismic vulnerability of steel-concrete composite bridges with abutment transverse restraints. In this paper, the Extended Incremental Dynamic Analysis (EIDA) method is used to account for all sources of aleatoric uncertainty. EIDA is applied to a benchmark SCC bridge system with dual load path to estimate the first- and second-order statistics of the EDPs of interest, to assess the sensitivity of the structural response to the model parameter uncertainty, and to evaluate the seismic vulnerability accounting for all pertinent sources of uncertainty.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
