f GEOPHYSICAL SIGNATURES OF CRACKING AND SELF-HEALING OF SOILS DURING LAB-SCALE SIMULATIONS

Internal erosion in earthen embankments occurs when a critical combination of hydraulic gradient, in-situ stress conditions, soil porosity and intrinsic permeability results in uncontrolled seepage and the transport and migration of soil particles in localized areas. Concentrated embankment seepage and erosion will also occur within open cracks that can result from strong-motion earthquakes and uneven or discontinuous settlement. Acoustic methods in combination with electrical geophysical methods have not been used yet as a tool for detection, characterization and continuous monitoring of subsurface internal erosion initiation in its early stages. Passive acoustic emission (AE), self potential (SP) and cross-hole tomography (CT) are being investigated for suitability as long-term, remote and continuous monitoring techniques for internal erosion and cracking of embankment dams.