Heterogeneous Influence on Hydro-Thermal Behaviors Within the Core of an Embankment Dam

Abstract

Spatial variations of the hydraulic conductivity within compacted till cores are the result of heterogeneity, which are also the consequence of variability in source material and compaction conditions. This paper deals essentially with a numerical analysis of the influence of heterogeneity on hydro-thermal behaviors of dam QA-01 in northern Quebec. Input parameters from existing studies and a coupled heat and mass transfer formulation were used to model the monthly temperature profiles at the centerline of the core. Firstly, the parametric studies performed with the presence of more pervious layers within the core with different values of hydraulic conductivity were considered in the model. The obtained results of temperature distributions and time lags were used to evaluate the predictions for various conditions associated with the presence of pervious layers in the impervious core. Secondly, the model was then applied to dam QA-01 with the consideration of actual thermal and hydraulic properties. Modeled temperature profiles were finally compared with measurements to assess the heterogeneous influence. The close agreement between predictions and observations above the elevation of 340 m in the core was obtained. The numerical results also verify the existence of another more pervious zone below the elevation of 340 m.