The assessment of dam’s safety is complex task that has to be considered from numerous aspects by including of various loading states. The structural safety requirements must be met in order to ensure the dam stability.

The application of the finite element method has led to significant changes in the treatment of the arch dam stability, enabling non-linear spatial analysis, analysis of the arch dam for different loading states (gravity and water load, temperature effect), as well and inclusion of the dam foundation in the analysis. Also, application of contact elements for simulating the behaviour on the interface concrete-rock in the dam abutments and foundation as well and the behaviour on the interface concrete-grouting material in the joints in the dam body is enabled.

In this paper some aspects of the safety evaluation in accordance with the advanced approach for dam analysis regarding the stress-strain state is illustrated for the case of “St. Petka” dam, a 64 m high arch dam on River Treska in nearby of city Skopje, commissioned in 2012.