Application of advanced bounding surface plasticity model in static and seismic analyses of Zipingpu Dam

The strong ground motion of the Wenchuan earthquake that hit the Zipingpu Dam in China in 2008 has provided an excellent benchmark to study the behaviour of large modern rockfill dams subjected to seismic loading. The performance of the dam during construction and prior to and after the earthquake loading has been recorded with good accuracy, and provides a reliable database to examine the reliability of available constitutive models and numerical methods in predicting the static and dynamic behaviour of embankment dams. In this paper, an advanced bounding surface plasticity model has been used in a series of numerical analyses to study the static and dynamic behaviour of Zipingpu Dam. The model can take into account particle breakage that may occur in monotonic and cyclic loading of rockfill materials. The material parameters required for the model are calibrated based on the results of available monotonic and cyclic triaxial tests. In the numerical procedure, the staged construction of the dam and the subsequent impounding of the reservoir are simulated, followed by dynamic loading. At each stage, the results of the numerical analysis are compared with in situ monitoring records of the dam. The results of the numerical simulation and the displacements measured after the earthquake are also compared with those estimated by two simplified engineering procedures that are routinely used in practice. The effectiveness and applicability of the simplified procedures to such a large dam subjected to an earthquake with a long duration is also discussed.