Flowthrough Rockfill Embankments: Behavior in Subzero Temperatures

Abstract

To date there is virtually no information on the behavior of flowthrough rockfill structures in subzero temperatures. This paper presents new insights into this behavior through consideration of the results of laboratory experiments and by systematically quantifying the relevant heat fluxes that might occur in nature. By applying an order-of-magnitude analysis to a fictitious prototype, it is shown that the viscous dissipation of hydraulic energy is sufficient to prevent internal ice clogging in all but very extreme climatic conditions. This dissipation of hydraulic energy did not, however, prevent surficial ice growth on model dams functioning at around −10°C to −15°C in the laboratory. An approximate degree-day–based ice-growth coefficient is presented and the reasonableness of this coefficient is discussed. An example calculation is used to illustrate the steps that might be involved in a typical heat-budget computation for such flowthrough structures.