| The stability and deformation of Waba Dam following new seismic requirements is evaluated using the prevailing methods of pseudo-static analysis and dynamic non-linear analyses. Waba Dam is a low but wide earthdam of clayey materials overlying a deep deposit of sensitive clay in Eastern Ontario with moderate seismicity. To assess stability, the instantaneous safety factor was calculated based on the conventional and a proposed method considering dynamic forces. While the dam is considered problematic from the pseudo static analysis, it is acceptable based on the dynamic analysis. Review of the various factors for the discrepancies shows that the force-based dynamic analysis is more reliable for dynamic stability analysis.; Deformation analyses show that there would be zero permanent deformation from the pseudo-static methods but some definite permanent deformations from an elasto-plastic analysis but within tolerable limits. Parametric studies have been conducted to cover possible ranges of soil parameters and ground motions. The results show that the performance of the dam will be acceptable. |
