Abstract:
The ability to anticipate and avoid failures in concrete dams necessarily includes a detailed analysis
of the mechanical/hydraulic properties and monitoring data relating to the dam -foundation system,
an in-depth analysis of the geometry of the foundation rock mass, complex numerical analysis of
dam behaviour and quantitative interpretation models. This ability to assess the safety of the damfoundation
system in an integrated way still needs to be improved, namely by incorporating coupled
models that consider the significant interdependence between the mechanical and hydraulic
behaviour. In addition, the models for interpreting hydraulic quantities are based on methodologies
developed for the interpretation of the mechanical model, which, as a rule, do not fit the observed
behaviour and do not consider the coupled behaviour. Coupled hydromechanical analysis of the
water flow through the foundation rock mass of a concrete dam is carried using a 2D numerical
model that allows seepage through the block interfaces and considers the influence of both grout
and drainage curtains. Numerical predictions obtained during cycles of filling and emptying the
reservoir are used to establish the influence lines of the hydrostatic p ressure on recorded
discharges. Two different dam heights and two different foundation geometries are evaluated. Also,
two different behaviour scenarios are assessed: i) linear elastic and ii) non -linear behaviour at the
concrete/rock and rock/rock interfaces. A series of different polynomial curves are adjusted to the
numerical predictions using the least square method to find the best fit equation which can later be
adopted in the development of more accurate quantitative interpretation methodologies of recorded
data.
