Seasonal temperature and stress distributions in concrete gravity dams. Part 1: modelling

Abstract

Seasonal thermal stresses have been found to contribute significantly to the long-term degradation of strength and stiffness of concrete dams located in northern regions. Temperature variations and the associated thermal stress and strain must be evaluated to define the initial loading conditions for safety analyses and develop defensive measures to ensure the durability of the exposed surfaces. This paper presents a finite element modelling procedure to determine the thermal response of concrete gravity dams. Heat transfer and structural analysis models of a typical dam–foundation–reservoir system are developed. The reservoir, foundation, and air temperature variations, as well as solar radiation, are evaluated from data collected from different sources. The rate of convergence of the numerical solution is examined, and a methodology to identify the critical temperature states and to compute the related stresses is presented. The results of extensive parametric analyses describing the thermal behaviour of concrete gravity dams located in northern regions are presented in a companion paper. Key words: gravity dams, thermal analysis, finite element method.