ABSTRACT
In the article the main results of geomechanical and related geophysical investigations of properties of the rock foundation of the Kankunskaya HPP concrete gravity dam in South Yakutia are given. The dam is designed for construction on the Timpton River in narrow canyon-type river valley. Proposed height of the dam is 230 m. The dam foundation is composed of frozen strong rock represented mainly by granite and granite-gneiss.
The set of studies consisted of: plate-bearing tests for determination of deformation properties of the rock mass foundation; pressure meter tests; shear tests on concrete plates; geophysical investigations in the places of geomechanical tests for estimation of dynamic characteristics of the rock mass and obtaining correlation dependence between static and dynamic deformability indices of the dam foundation rock; laboratory tests on determination of the main physical and mechanical properties of rock.
Scope of performed investigations permitted to estimate stress strain characteristics of the dam foundation in different rock quality zones.
In the article the comparison of the rock mass strain characteristics obtained in frozen and unfrozen rock as well as by means of performance of different-scale investigations is given.
The results of performed investigations provided the basis for assigning the design geomechanical characteristics of the rock foundation at the dam site.
