Seismic Fragility Analysis of Aqueduct Structural Systems Based on G-PCM Method

Abstract

In order to accurately predict the seismic fragility of an aqueduct system, the General Product of Conditional Marginal (G-PCM) method was applied to the seismic fragility analysis of the aqueduct structural system, consisting of interrelated components such as the aqueduct body, pier, and support. First, a finite element dynamic analysis model of a three-span aqueduct with an equidistant simply-supported beam was established, based on the OpenSees platform. The uncertainties of structure, ground motion, and structural capacity were considered, and then the incremental dynamic analysis (IDA) method was used to calculate the seismic fragility of the three individual components, such as the aqueduct pier, the plate rubber bearing at the cap beam, and the PTFE sliding plate bearing at the aqueduct platform. Subsequently, seismic fragility curves of the aqueduct system were established using the G-PCM method and were compared with the traditional second-order bound method. The results showed that the two bearings of the aqueduct are more likely to be damaged than the pier; the failure probability of the aqueduct system is higher than that of any single component; and the seismic fragility curves of the aqueduct system acquired via the G-PCM method were all within the range of the failure probability obtained by the second-order bound method and had a better accuracy, which is suitable for the seismic fragility analysis of multi-failure mode aqueduct systems.