HORIZONTAL DISPLACEMENTS OF ROCK FOUNDATIONS OF DAMS.

Considerable experience in observations of horizontal displacements of rock foundations has already been gained at Soviet hydro developments. The object of observations was not only the boundary along the contact of the concrete and rock but also the rock mass, which recently has been called the region of interaction of the dam and geological environment. Knowledge of the size and shape of this region enables geologists and hydraulic engineers to more reliably predict and assess deformation processes and geodesists to more well-foundedly develop and refine methods of measurements and to select the location of the initial geodetic points relative to which the displacement will be determined. The results of observations at a number of dams presented made it possible to estimate the boundaries of the 'region of interaction,' character and amount of displacement, and certain regularities of the deformation processes. Brief information about the methods of measurement and accuracy of the results obtained are given.