An integrated numerical/physical approach to investigate the seismic performance of a zoned earth dam

Fully coupled time-domain dynamic numerical analyses provide a useful insight into the evaluation of the seismic performance of earth dams, taking into account factors such as partial saturation, complex soil behaviour and boundary conditions. However, the accuracy of their predictions is highly dependent on the calibration of the numerical model, either using monitoring data from real case histories or the results of small-scale models tested in the geotechnical centrifuge. This paper describes an integrated numerical/physical approach to investigate the seismic performance of a zoned earth dam, taking into account the coupled hydro-mechanical response under both static and dynamic conditions. The numerical model was calibrated using data from a geotechnical centrifuge test on a small earth dam simulating reservoir filling and seismic loading of increasing intensity. Comparison of the results of the analyses with the data from the centrifuge test demonstrated the ability of the finite element model to reproduce the key aspects of the observed behaviour. It is shown that the integrated physical and numerical approach is effective in developing a robust and reliable prediction tool that allows the effect of the most relevant factors to be studied during extreme scenarios. Some peculiarities in the behaviour of this class of earth structures are highlighted, providing guidance for a rational assessment of their seismic performance.