PLT - Using State-of-the Art Geophysical Technologies to Assess Earthen Embankments

The current U.S. dam and levee inventory which includes over 14,000 high hazard non-federal dams, averages over 70 years of age but providing an accurate assessment of aging infrastructure can prove difficult. Structure location, site access, geologic setting, and size often presents complications for conducting accurate condition assessments or geohazard characterizations. Recently developed geophysical methods, including Semi-Airborne Electromagnetics, 3D Seismic SPT, Full Waveform Tomography, and Fiber Optic Sensing Technologies, along with revised applications of standard geophysical methods, provides cost-effective, accurate approaches for levee and dam geo-characterization. Phasing various geophysical methods (types, scale of survey and specific applications) can reduce uncertainty in the characterization process and focus existing and more traditional methods on targeted problem areas.

Further, the use of Unmanned Aerial Vehicles (UAVs) to support survey and geophysical instrumentation can overcome several difficulties in dam and levee characterization including ground access and ensuring consistent instrument height over rough or steep terrain. This targeted land-based geophysical surveys can then the specific and critical data required for proper engineering assessments. New geophysical methods take advantage of standard geotechnical data and methods to maximize the information gained over the life of the project. These new geophysical applications and technologies are cost effective, reduce uncertainty and risk in dam and levee characterizations, and allow prioritization of the survey effort to take advantage of what information is being learned as the work progresses.