Seismic fragility analysis of complex landscape covered bridge

The finite element models of landscape covered bridges with and without upper building structures and models with node qualities simulating upper building structures were established accounting for uncertainties of ground motions and structures. Seismic fragility curves of the three models were developed using nonlinear time history analysis method and the impacts of upper building structures on bridge seismic performance were assessed. The results show that: in the earthquake, the upper building structures increased the seismic demands of pier and bearing as well as the seismic vulnerability of landscape covered bridges, especially under severe and completely damaged states. Therefore, the effects of upper building structures must be accurately assessed in the seismic design or vulnerability assessment of landscape covered bridge structures.