Numerical modelling of the thermo-mechanical behavior of concrete arch dams during the first filling of the reservoir

Abstract

To understand the performance of the dam during the first filling, it is crucial to predict in real time the displacement and the stresses due to the water reservoir level and environmental conditions. Particular attention must be given to environmental actions which have a significant effect on arch dams. Hence, a correct simulation of the first filling should entail, amongst other, a proper tran- sient heat transfer analysis to determine the temperature distribution in the dam. The purpose of this paper is to describe the main issues concerning the struc- tural and geotechnical modelling as well as the heat transfer and boundary con- ditions simulation necessary to obtain a representative behavior of the dam during the first filling. An example of numerical simulation of the behavior of an arch concrete dam during the first filling of the reservoir is also given. The temperature distribution inside the dam was estimated using a finite element model which considered the effects associated with air temperature, water temperature and solar radiation. The structural response of the dam was assessed using the same finite element model. In this case, the contraction joints and the contact surface rock/concrete were included in the model and represented by zero thickness interface elements. The validation of the computed temperatures and the induced displacements was performed by comparison with the values measured with the monitoring system installed in the dam.