Volumetric Remote Monitoring of an Earth Embankment: Part II - Visualisation and Condition Assessment

We describe a study in which time-laspe electrical resistivity tomography (ERT) has been used to investigate an aged (>100 years old) section of earth embankment on an operational railway (Great Central Railway (GCR), Nottingham, UK). Monitoring has been undertaken using a permanently installed ERT array extending across the embankment from toe to toe. Part I of the study (Munro et al., 2012) describes our approach to ERT data collection and processing, including corrections for seasonal temperature changes, and the implementation of a procedure to translate time-lapse resistivity models into gravimetric moisture content. Here, in Part II of the study, we use the derived models of gravimetric moisture content to assess the internal condition of the earth embankment. These results show that this can be monitored noninvasively, and at a high spatial resolution, using ERT.