Comparation of calculated and survey monitoring displacements for St. Petka dam

Abstract

The assessment of dam’s safety is complex task that has to be considered from numerous aspects by including of various factors. The following safety requirements are to be fulfilled in order to ensure the dam stability: (i) functional (considering the degree of satisfaction of the users’ objectives), (ii) economic (considering the relation between costs and gains), (iii) hydrological (considering the acceptable risks for evacuation of the flood waters), (iv) hydraulic (considering the capacity of the conduits), (v) seepage (considering the intensity of the hydrodynamic parameters) and (vi) structural (considering the effects of static and dynamic loads). The application of the finite element method has lead 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), including the dam foundation within the analysis. Also, application of contact elements for simulation of the behaviour on the interface concrete-rock in the dam abutments and foundation as well as the behaviour on the interface concrete-grouting material in the joints in the dam body is enabled. The process of calibration of the results obtained by numerical analysis and monitoring data is continuous in the same time improving the numerical model and monitoring instrumentation. In this paper a comparison of part of the output results from the numerical model with monitoring data is illustrated on the case of St. Petka dam, a 64 m high arch dam on River Treska in Macedonia, commissioned in 2012.