Seismic Design of the I-195 Relocation Bridges: The 'Iway' Project, Providence RI

摘要

Sixteen new bridges were designed to replace the existing Rhode Island I-195 interchange. The new bridges include a steel network arch bridge, curved-steel box-girder spans, steel I-girder curved spans, precast-concrete spans, and rigid-frame cast-in-place concrete spans. Foundation types are drilled shaft, H-pile, and shallow foundation. These bridges are situated in a moderate seismic hazard zone and in an urban area, which introduces significant architectural restraints. A 2,500-year-return earthquake period was designated for seismic design and detail; the non-linear dynamic analysis method, concrete member ductility design, and construction conflict and solution are presented. Hinge-zone plastic mechanism and non-linear strain analysis were applied to relieve some of the reinforcement detail congestion. The two-stage seismic design methodology used and the load and resistance factor design (LRFD) design specification for moderate seismic hazard zone are also discussed in this paper.