Foundations of gravity dams: Rock mechanics requirements

摘要

The requirements for the foundation of concrete (CVC, RCC, hardfill) dams are usually expressed in qualitative terms: “sound rock”, “fresh rock”, “below the decompressed surface strata”... That lefts a big margin to the engineering judgment of the dam construction responsible. On the other hand the requirements depend on the dam class, and material (CVC concrete has bigger deformation modulus than RCC and hardfill, and therefore requires a less deformable foundation). In this paper the minimum requirements for the rock mass in the foundation of concrete gravity dams (CVC, RCC, hardfill) are expressed in terms of rock mechanics parameters: rock mass longitudinal velocity (celerity), measured by geophysical methods; ISRM weathering degree; unconfined compressive strength; rock mass deformation modulus; geomechanics classifications classes.