Use of Signal Processing to Study Internal Erosion in Porous Media

Internal erosion is considered to be a major cause of flooding in earth dams. Though the mechanism of initiation is well defined (i.e. suffusion, backward erosion, contact erosion and concentrated leak), the ability to detect it and prevent catastrophes from happening is still being investigated. This study focuses on backward erosion also known as piping. It aims at using geophysical techniques, mainly seismic, to monitor water seepage in porous media and detect the initiation of backward erosion in a controlled environment. For this purpose, a laboratory setup was built to better understand the effect of piping evolution on the seismic response. The seismic activity was monitored in energy and rate with the increase in hydraulic head (increase in flow) highlighting the presence of major events that accelerated towards the end of the experiment leading to the collapse of the sample.