Performance-based earthquake assessment of bridge systems including ground-foundation interaction

Performance-based earthquake engineering (PBEE) assessment studies on highway bridges can only address post-earthquake repair fully when considering the response of the bridge-foundation-ground and the consequences of damage and repair to all system components. In this paper, nonlinear time history analysis of coupled bridge-foundation-ground systems is coupled with a PBEE framework to investigate a typical highway overpass bridge founded on different soil profiles. The prototype bridges are typical reinforced concrete highway overpass bridges with single-column bents founded on four sites of varying stiffness and strength profiles ranging from rigid rock to weak upper soil strata. Probabilistic repair cost and time response quantities are used to contrast performance of the four scenarios. Intensity-dependent repairs, repair hazard curves, and repairs disaggregated by performance groups indicate contributions to system repair for each scenario. A sensitivity study is presented that demonstrates the most important parameters to be the damage state and repair quantities related to the foundations and abutments.

► Performance-based repair metrics for coupled bridge–ground-foundation system. ► Four soil profiles considered: rigid soil, competent, poor shallow, and stiff strata. ► Damage limit states and repair quantities for performance groups. ► Repair cost and repair time loss models and loss hazard curves. ► Sensitivity to performance parameters shows importance of abutment and foundations.