Soft Rocks in Dam Foundation and Dam Sites
Dams built on a soft rock foundation or on rock masses including weak aspects have the same approach as for other types of rock masses, nevertheless, they deserve more attention since the available geomechanical parameters are lower than those on more competent foundations. Depending on the loads applied by the dam structures, the soft rocks do not differ from other types of rock mass, and the approaches for dealing with the parameters, design criteria and stability as well, are the current ones.
However, soft rock may imply in insufficient load capacity or lack of discontinuity global strength. For these cases, special measures or different approaches to attain dam stability are needed and are partially addressed in this text. This chapter deals with possible ways of considering soft rocks as dam foundation. Discussions on rock mass and discontinuity strengths, deformability, seepage, and failure modes are also presented. With the purpose of illustrating the discussions some real cases are described closing the chapter.
KeywordsSoft rocks Dam foundation Dam stability Rock mass strength Discontinuity strength
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