Geotechnical and Geology

Seepage analysis of embankment dam (Photo Source: Gannett Fleming).

“Information on foundation and reservoir conditions and on the natural materials available for construction is essential for the design of all dams. Investigations to gather such information are conducted in the field and in the laboratory, and analyses and reference work are performed in the office. For efficiency, these investigations must be properly planned. Subsurface explorations should not be started until all available geologic and soils data have been evaluated. The investigator should also be familiar with mapping, with logging and sampling methods, and with field and laboratory testing. Such a background and a knowledge of the capabilities and limitations of the various methods of subsurface exploration will lead to the selection of the most appropriate field methods and will save the time and effort that would otherwise be lost through ineffective procedures and duplication of effort”.^[1]

“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”.^[2]

“Geologic features may include faults, bedrock lows, discontinuities and voids, and groundwater”.^[3]