Authors:
C. R. Donnelly, B. S. A Tatone, A. Lisjak, O. K. Mahabadi, G. Grasselli
Canadian Dam Association Conference (CDA), Niagara Falls, Canada, October 2010
Abstract
The assessment of the stability against sliding, overturning, and shearing of a concrete dam, founded on a bedrock foundation is a fundamental component of ensuring the safety of a gravity dam. This paper illustrates the use of a new numerical tool, called the combined finite-discrete element method (FEM/DEM), to evaluate the stability of concrete gravity dams founded on rock. With this numerical tool, the transition from continua to discontinua can be simulated. Thus, realistic shearing behaviour, including progressive asperity damage through intact rock or concrete can be simulated. In doing so, deformation of a dam can be modeled considering the actual foundation profile without selecting the failure mode a priori. Indeed, the roughness of the rock foundation is explicitly accounted for by the model geometry and the stability of the dam can be estimated regardless of the complexity of the failure process. A typical two-dimensional gravity dam cross-section from the literature is analyzed with the new methodology to demonstrate its applicability. To assess the relative degree of stability, a new definition of the factor of safety is established. The results obtained are subsequently discussed and compared to those obtained via conventional limit equilibrium analysis. Following from the results, thoughts on future research using FEM/DEM to analyze dam stability are provided.
