Integration of creep into a modified hardening soil model for time-dependent analysis of a high rockfill dam

This paper proposes an approach to extend a modified hardening soil model into the time-dependent analysis of high rockfill dams. The key feature of the extended model is the integration of a creep model and the double yield surface elasto-plastic model, via modifying the hardening functions. The integrated model is validated by a laboratory multistage creep test. Results from three-dimensional analyses including the without creep and with creep considerations of the Nam Ngum 2 dam have been compared with the in-situ measurements. The prediction of dam deformation can be significantly enhanced by the proposed model.