Author(s): Emily J Parker

Abstract: This research investigates the stability of embankment dams using two distinct methods: limit equilibrium methods (LEM) and finite element method with shear-strength reduction (FEM-SSR). The study aims to compare the performance of these methods under steady-state seepage and rapid drawdown conditions. Three LEM formulations—Bishop, Janbu, and Morgenstern-Price—were applied alongside FEM-SSR to assess their accuracy and reliability in predicting the factor of safety (FoS) and strength reduction factor (SRF) for a representative embankment dam section. Results indicated that while LEM methods generally overestimated stability compared to FEM-SSR, the latter provided more conservative and accurate assessments, especially under rapid drawdown conditions where transient seepage effects become critical. FEM-SSR proved particularly sensitive to changes in dam geometry, soil properties, and drawdown rates, reflecting the importance of accounting for seepage-deformation coupling. Statistical analysis revealed significant differences in stability predictions between the methods, highlighting the need for FEM-SSR in the final stability checks, especially for complex or irregular dam configurations. The study emphasizes the complementary use of both methods, suggesting that LEM can be applied for initial screening while FEM-SSR is better suited for detailed design evaluations and post-construction monitoring. Practical recommendations include integrating transient seepage analysis with FEM-SSR for flood-prone regions, accurate soil characterization, and encouraging the use of FEM-based tools in routine dam safety evaluations.

Pages: 39-44 | Views: 5 | Downloads: 4

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