Funcho dam consists of a thin double-curvature arch with a maximum height of 49m supported by a foundation pulvino and two artificial concrete abutments. The dam is founded on a schist and greywacke rock mass that presents lithological, structural and alteration state heterogeneities. There are significant differences in deformability between the two banks. During the construction vertical displacements in the foundation were recorded. Based on this information, back-analysis techniques are used to determine the average deformability of each zone of the rock mass. A finite element model is used to represent the behaviour of the structure.
Le barrage du Funcho consiste d'une vôute avec une hauteur maximale de 49 m, appuye Sur pulvino et deux appuis artificiels en beton. Le barrage est funde sur un massif rocheux constitue par des schist et des greywackes, avec des heterogeneites lithologiques, structurelles et d'etat d'alteration. II y a des differences significatives entre les deux rives. Pendant la construction on a enregistre les deplacernents verticaux dans la fundation. Des techniques de "back-analysis" ont ete utilizees pour determiner la deformabilite moyenne de chaque zone du massif à partir de cette information. Le comportement de la structure a ete represente par un modèle d'elements finis.
Funcho-damm besteht aus einer duennen Bogenmauern mit einen maximalen Höhe von 49m, der sich auf einem pulvino und zwei seitliche Betonblöcke stuetzt. Der Damm ist auf einer Schist ung Grauwacke Gesteinmasse gegruendet, die heterogene litologische, strukturelle und Alterations Aspekte prasentiert. Es gibt betrachtliche Verschiedenheiten zwischen beiden Ufern. Wahrend der Konstruktion wurden die vertikalen Bewegungen in der Gruendung gemessen. Auf dieses Information basiert und durch Backanalysetechniken wurde die Verformbarkeit jeder zone der Gesteinmasse bestimmt.
The risks inherent to large dam projects require elaborate methods for monitoring and safety control. These activities, to be conducted throughout the life span of the structure, rely on the comparison of the observed response with models assumed to represent its behaviour. A valid assessment of the performance of these works demands a good knowledge of their structural behaviour, the properties of the materials, and reliable data on its real response. Therefore, field tests must be performed prior to design to characterize the rock mass jointing, and its mechanical and hydraulic properties. During construction, the foundation testing is completed, and structural material properties are determined. The monitoring plan should incorporate the instrumentation needed to record the variables most representative of the structure's behaviour. The first filling of the reservoir is the first real test of the dam, so during this period its response is carefully monitored, and compared with the predictions of models, typically the models used in design. The reliability of models depends fundamentally on the parameters that govern material behaviour. As a rule, these parameters are defined by the tests performed before and during construction. For concrete dams, the determination of the structure's properties does not present significant difficulties. The most complex tasks lie in the characterization of the rock foundation and its representation in a numerical model. System identification techniques are thought to be an important tool in this context. The computer resources widely available allow the use of the minimization methods suitable to the estimation of the most likely values of the parameters, given the measured structural response. This paper presents a methodology for the identification of the deformability of concrete dam foundations, based on the vertical displacements measured by foundation extensometers installed during the construction.