Seasonal Temperature Monitoring and Modelling for Seepage Reconnaissance in an Embankment Dam
T. Yun, K.E. Butler, K.T.B. MacQuarrie, B. Mclean and I. Campbell
Event name: 24th European Meeting of Environmental and Engineering Geophysics
Session: Investigations of Landfills, Urban Areas & Industrial Sites A & Investigations - Seismic Hazard and Dynamic Characterization A
Publication date: 09 September 2018
Info: Extended abstract, PDF ( 2.26Mb )
Price: € 20
Spatial and temporal variations of temperature have been monitored and modelled at the interface between the compacted clay till core of an embankment dam and an adjoining concrete diversion sluiceway structure at the Mactaquac Generating Station, located on the Saint John River near Fredericton, NB. The measurements were acquired using a fibre optic distributed temperature sensing (DTS) system installed in a 50 m long borehole drilled into the concrete structure within 0.5 m of the interface. Two significant temperature anomalies were observed. A 3D finite element model was developed to simulate the temperature distributions within the dam resulting from the seasonal variations of air and headpond temperature. Anomalous seepage zones near the interface were simulated in the concrete and embankment independently, and in both simultaneously. The results reveal that the application of the DTS passive monitoring method is feasible to identify the potential seepage zone near the dam/concrete interface. Numerical modelling can indicate whether seepage is more likely occurring in the concrete or in the embankment, but other details of seepage path geometries and seepage rate are not as well constrained.