Seismic Performance of Sacrificial Exterior Shear Keys in Bridge Abutments

Performance evaluation of sacrificial exterior shear keys in bridge abutments under simulated seismic loading was conducted in terms of damage levels that were observed during testing. These experiments provided results that were used to make realistic assumptions on the load-deformation response of as-built sacrificial exterior shear keys as well as their peak and post-peak performance under cyclic loads. Experimental results were subsequently used to develop a two-spring component hysteretic model for modeling the seismic response of shear keys at the abutments. The mathematical rules used to describe the hysteretic model are presented. Analyses show that this model was able to reproduce reasonably well the cyclic response of the investigated keys. The hysteretic model and key experimental results are presented in this paper.