Seismic Deformation Assessment of a Dam Founded on Low Plastic Fine- Grained Soils under Strong Earthquake Shaking

December 10, 2020

This paper presents the seismic assessment of a central core embankment dam partially founded on relatively weak, low plastic fine-grained soils. Characterization of low plastic fine-grained soils, especially their cyclic and postcyclic behavior was critical in assessing the seismic performance of the dam. A site investigation and laboratory testing program was undertaken to characterize the low plastic fine-grained soils and their behavior under the cyclic loading. An effective stress based constitutive model UBCSAND, developed at the University of British Columbia, Canada and implemented in the computer program FLAC, was shown to be able to capture the characteristic cyclic behavior observed in the laboratory cyclic direct simple shear tests. Seismic deformation analyses using the model showed that, although the low plastic fine grained soils will not behave like loose sand, it can still cause significant displacements due to accumulation of strains during cyclic loading. Thavaraj, T., Stevenson, G. and D. Siu. 2016. “Seismic Deformation Assessment of a Dam Founded on Low Plastic Fine-Grained Soils under Strong Earthquake Shaking,” in: Geo-Chicago, Sustainability, Energy and the Geoenvironment, Proceedings, Chicago, Illinois, August 14-18, 2016.