Effects of shear keys on nonlinear seismic responses of an arch-gravity dam

In the paper, the added tangential nonlinear springs are introduced to represent the effects of one-way and two-way shear keys. The added tangential stiffness coefficient is relative to the joint opening and the relative tangential movement and determined numerically by using a refined model of shear keys. The user subroutine of nonlinear spring elements has been implemented into ABAQUS program. The seismic responses of an arch-gravity dam are mainly examined. It is shown by the results that a significant increase of about 17%-30% in joint opening can be observed for the dam with one-way shear keys; the two-way shear keys are beneficial to restrain the sliding displacement along both the radial and vertical directions, whereas the one-way shear keys mainly restrain the displacement along the radial direction; for the dam with shear keys, the maximum arch stress is increased, the cantilever stress is reduced, and the location of the maximum cantilever stress is also moved from the dam heel to the midheight of the cantilever.