Geotechnical Exploration
A USBR geotechnical engineer collecting a soil sample. (Wikipedia) |
Before any construction or design work can be completed at a potential dam site, conducting geotechnical subsurface and onsite material exploration is essential. These explorations consist of both invasive and non-invasive sampling methods. Invasive geotechnical sampling methods may include drilling boreholes and taking core samples from the overburden and bedrock within the footprint of the dam and its appurtenances, taking soil samples from open pits, or using correlative field tests. Non-invasive geotechnical sampling methods may include but are not limited to using geophysical methods involving emitting ground penetrating radar or creating mechanically induced seismic waves.
The intent of the geotechnical investigation is to characterize the foundation conditions and uncover any potential problems at the project location. Any potential problems that are identified by thorough investigation can be addressed in the design of the various features of the dam.
“Investigate site geologic and geotechnical conditions in a manner that adequately examines embankments, spillways, abutments, borrow areas, and foundations to enable adequate evaluation of all design conditions. Provide appropriate intensity and detail of these investigations for the class of dam, complexity of site geology, and the data needed for the dam design” (TR 210-60 Earth Dams and Reservoirs, NRCS, 2019).[1]
Examples
Best Practices Resources
Technical Release 210-60: Earth Dams and Reservoirs
Trainings
Citations:
Revision ID: 2800
Revision Date: 09/13/2022