Recent News

Stability Analysis Of Katse Dam Foundation Wedges Under Static And Seismic Conditions

Download Publication (PDF)

SANCOLD 2025 ANNUAL CONFERENCE 5-6 November 2025

By F. Smit, ARQ Dams Pty Ltd
-co-author R Cassells, L Phooko, R Hlajoane and L Hattingh, South Africa.

The last Panel of Expert (POE) review of Katse Dam in 2018 concluded that the original design calculations although appropriate at the time, does not satisfy all the current international accepted criteria and procedures. This specifically pertains to the abutment seismic stability during normal operation and extreme conditions. As a result, the dam owner (LHDA) initiated a project to perform a finite element analysis of the dam.

Concrete arch dams are among the most efficient and structurally complex dam types, utilizing their curved geometry to transfer hydrostatic and hydrodynamic loads into the abutments. This load transfer mechanism makes the integrity of the foundation particularly critical. Therefore, a detailed analysis of existing foundation rock wedges—formed by faults, joints, and other geological discontinuities—is essential to ensure their stability under both static and seismic loading conditions.

This paper discusses the three-dimensional foundation wedge analyses of Katse Dam. Particular attention was be given the dynamic analysis including the interpretation and presentation of results as well as cognisance given to the potential failure modes.