Defect detection and seepage characterisation for the Älvkarleby test embankment dam using resistivity‐IP monitoring and 3D flow modelling

The overall goal of this project is to develop improved monitoring techniques for the early detection of internal erosion in embankment dams. The aim is to evaluate the capability of the ERT-IP/DCIP methods as long-term monitoring techniques in embankment dams and assess their ability to detect and locate defects caused by construction flaws or internal erosion.

Monitoring through instrumentation can detect internal erosion at early stages, allowing appropriate measures to be planned with minimal disruption to power production. Internal erosion is often difficult or impossible to detect before it has progressed to the point where sinkholes appear in the dam, and there is a clear need for new and improved monitoring methods.

In 2019, Vattenfall invested in a new test facility in the form of an embankment dam adjacent to the Älvkarleby Laboratory. The dam is constructed in the same way as conventional embankment dams, with a central core, filter zones, and supporting embankments. The purpose is to investigate the possibility of testing the detection of small embedded defects under controlled conditions, varying in location, size, and character, using several geophysical methods.

This project will evaluate data from long-term measurements using combined ERT-IP/DCIP from the test dam in Älvkarleby, with a focus on the IP component of the data, which has not yet been analyzed.