| Title |
A Seismic Reliability Study of Simple Nonlinear Structures Considering the Uncertainties of Parameters in Earthquake-Structure System |
| Abstract |
A seismic reliability analysis was carried out to evaluate seismic reliability index of code-designed simple nonlinear structures by combining seismic risk analysis, stochastic model of seismic motion, nonlinear dynamic analysis, and structural reliability theory. In particular, the statistical uncertainties of structural system and soil filter parameters were considered in analysis by treating them as random variables. The damage-related limit state of simple R/C structures was defined by ductility demand, which is one of the traditional and qualitative measures of seismic damage. The results of this study, compared to the results of other dynamic limit state-based studies, indicate that seismic reliabilities of current code-designed structures are much lower than member-level target reliability against gravity loading. But these results should be interpreted prudently. If overstrength of structures as built is admitted, which often can be seen in shaking table test and actual building behaviors during earthquakes, the apparently low reliability index shall increase. For rigorous assessment of seismic reliability, it seems important to consider real dynamic resisting capacity of code-designed structures as built and to use more quantitative and calibrated damage index to define damage-related limit state. |