Shear Key Research Project Literature Review and Finite Element Analysis

The objectives of this study are to determine how much strength and resistance the shear keys develop relative to the typically implemented finite element (FE) models of concrete arch dams. This study will give risk teams a more defensible basis when judging if an arch dam maintains its arch action during seismic events that move the dam upstream and open contraction joints. This study will also help risk assessment teams better estimate probabilities of failure for arch dams with and without shear keys.

This report proposes a method that assesses the behavior in the joint to provide further evaluation on the stability of arch dams with and without shear keys. Generically, the proposed method compares the behavior of the typically implemented contraction joint model with known joint behavior and geometry.
The known joint behavior is based on past research on shear key failure (Kaneko et al., 1993a, 1993b), sliding in rough, undulating rock surfaces (Hoek and Bray, 1981; Ladanyi and Archambault, 1970), and the behavior of an FE model of typical shear keys that was developed as part of this study. The proposed method provides a means of assessing the effects of contraction joints without changing the current methods utilized or increasing the complexity of the current methods utilized for structural evaluation of concrete arch dams.