Estimation of Seismically-Induced Crest Settlement of Earth Core Rockfill Dams

The settlement at the dam crest induced by earthquake loading is an important design parameter widely used to evaluate the seismic performance of dams. Two-dimensional nonlinear dynamic analyses were performed to calculate the dam crest settlement of earth core rockfill dams (ECRDs). The numerical model was first validated against centrifuge test measurements. Comparisons showed that the numerical model provided reasonable estimates of the measured response. A series of dynamic numerical analyses were performed for a wide range of ground motions. The calculated settlements were revealed to compare well with field recordings of dam crest settlements. The settlements were also plotted against ground motion parameters, including free-field surface peak ground acceleration (PGA), peak ground velocity (PGV), Arias intensity (Ia), and moment magnitude (M). Predictive equations for the crest settlement were also presented. It wes demonstrated that PGA provided a good estimate of the settlement, but Ia provided the most favorable fit according to the calculations. Additionally, multiple parameters models were also presented to enhance the accuracy of the predictions.