INTEGRATED SEISMIC-HYDRAULIC PERFORMANCE ASSESSMENT OF A ZONED EMBANKMENT DAM APPLICATION TO THE MEMVE’ELE HYDROPOWER PROJECT (CAMEROON)

Abstract

This study examines the coupled seismic-hydraulic response of the Memve’ele zoned embankment dam in Cameroon under multi-component seismic excitation. Conventional dam safety assessments often consider only translational ground motions and two-dimensional analyses, which may underestimate the influence of rotational and torsional seismic components on the response of large embankment dams. To address this limitation, an integrated numerical framework is developed that combines finite-element seepage, stability, and stress-strain analyses in GeoStudio with external computational routines implemented in MATLAB. The methodology enables pseudo-three-dimensional seismic loading by incorporating translational, rocking, and torsional motion components into multiple two-dimensional model slices. Seepage and transient hydraulic analyses are conducted to evaluate phreatic surface evolution, pore-water pressure distribution, and slope stability during reservoir operation. Dynamic response analysis is then performed to assess deformation patterns, stress redistribution, and safety factors under coupled hydraulic-seismic loading. Results indicate that the permeability and mechanical properties of the clay core strongly influence downstream seepage and stability conditions, while rotational seismic components significantly modify stress concentrations and displacement patterns within the dam body. The proposed semi-three-dimensional approach provides a practical tool for improving seismic safety assessment of zoned embankment dams.