Hidden Physics Beneath the Earth

This dam may appear solid, inactive and impenetrable, but there are many internal processes that are not visible on the surface. To “see” inside the dam, we use knowledge of geology and physics to create images of its interior. One of the primary causes of embankment dam deterioration is internal erosion. Over time, regions of a dam may become susceptible to water seepage pathways that could internally erode fine-grained material from its core. If left unchecked this could potentially lead to a breach. It is therefore important that dams be monitored continuously. The method I have been adapting for my research uses a system that injects electrical current into the dam through electrodes and measures the voltage drops between other electrodes. I have expanded this permanent system into the water to image deeper into the dam. With knowledge of the dam’s construction material, we can gain valuable information about the dam interior without drilling into it. Seepage pathways can be located by identifying areas where the internal electrical resistivity changes most rapidly following changes in the reservoir water. This information can be used to inform engineers on areas of concern, so they can focus their efforts on maintaining structural integrity.