Incremental dynamic analysis of concrete gravity dams including base and lift joints

The growth in computer processing power has made it possible to use time-consuming analysis methods such as incremental dynamic analysis (IDA) with higher accuracy in less time. In an IDA study, a series of earthquake records are applied to a structure at successively increasing intensity levels, which causes the structure to shift from the elastic state into the inelastic state and finally into collapse. In this way, the limit-states and capacity of a structure can be determined. In the present research, the IDA of a concrete gravity dam considering a nonlinear concrete behavior, and sliding planes within the dam body and at the dam-foundation interface, is performed. The influence of the friction angle and lift joint slope on the response parameters are investigated and the various limit-states of the dam are recognized. It is observed that by introducing a lift joint, the tensile damage can be avoided for the dam structure. The lift joint sliding is essentially independent of the base joint friction angle and the upper ligament over the inclined lift joint slides into the upstream direction in strong earthquakes.