I am planning to build a small jurisdictional-size earth dam. What sort of geotechnical exploration is needed?
A typical field investigation should seek to identify geologic hazards that could adversely affect the project, to characterize the engineering properties of available earth and rock construction materials, and to characterize the strength and permeability of the dam, spillway, and outlet foundations. Since each site and project is unique, exploration plans should be submitted to DSOD beforehand for review. DSOD should also be given the opportunity to observe the site conditions firsthand during exploration. A typical field investigation program includes understanding the geology of the site through geologic mapping, air photo analysis, test pits, and borings. The engineering properties of embankment and foundation soils are generally evaluated by sampling and laboratory testing, and field testing such as in-place density, penetration resistance, and permeability testing. Geophysical techniques, such as seismic refraction and shear wave velocity testing are sometimes used. Core drillin
