Direct Displacement–Based Seismic Design of Reinforced Concrete Arch Bridges

Abstract

This paper extends the direct displacement–based design (DDBD) procedure, which was developed for buildings and conventional bridges, to the special case of RC deck arch bridges. New design expressions are formulated for the yield drift and deformation capacity of bridge piers seated on arches. The proposed methodology is applied to three case study deck arch bridges in both the longitudinal and transverse directions, and the designs are validated by nonlinear time-history analyses. The results indicate that the proposed methodology is capable of capturing the deck displacement and pier chord rotation within a reasonable degree of accuracy, although the response of the arch bridge is complex and can be affected by higher modes. The research reveals that the arch displacement may be underestimated by the DDBD procedure, but because the arch displacements are very small in comparison with the deck displacement, the DDBD procedure is still successful in controlling peak chord rotation demands on the bridge piers.