Soft Rocks in Dam Foundation and Dam Sites

  • Ricardo AbrahãoEmail author


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.


Soft rocks Dam foundation Dam stability Rock mass strength Discontinuity strength 


  1. Abrahão RA, Degaspare JC (2016) Rebuilding Camará water supply dam, II International Specialized Conference of Soft Rocks, ISRM. Cartagena, ColombiaGoogle Scholar
  2. Barton N (1988) Rock mass classification and tunnel reinforcement selection using the Q-system. In: Kirkaldie L (ed) Rock classification systems foe engineering purposes, ASTM STP 984. American Society for Testing Materials, Philadelphia, pp 59–88CrossRefGoogle Scholar
  3. Barton N (2007) Rock quality, seismic velocity, attenuation and anisotropy. Taylor and Francis Group, London, ISBN 0-41539441-4Google Scholar
  4. Bieniawski (1973) Engineering classification of jointed rock masses. Trans S Afr Inst Civ Engrs 15:335–344Google Scholar
  5. Duffaut P (2013) The traps behind the failure of Malpasset arch dam, France, in 1959. J Rock Mech Geotech Eng 5:335–341CrossRefGoogle Scholar
  6. Hoek E (2007) Practical Rock Engineering. Course notes:
  7. Infanti N Jr, Kanji MA (1990) Estimating the shear stiffness of rock joints. In: International Symposium on Rock Joints, Loen. International Symposium on Rock Joints, vol 1. N. Barton and O. Stephansson, Oslo, pp 799–804Google Scholar
  8. Kanji MA (1990) Dam foundation on soft and fractured rocks: Problems and solutions. In: 3° Congresso Sulamericano de Mec. Rochas, Caracas, Soc. Venezolana Geotecnia, vol 1, pp 235–252 (in Spanish)Google Scholar
  9. Rocha M (1976) Some problems related to Rock Mechanics of low strength materials. Geotecnia. J Portug Geotech Soc 18:3–27. (in Portuguese)Google Scholar
  10. Rogers JD (2006) Lessons learned from the St. Francis dam failure. Geo—Strata Magazine of the Geo InstituteGoogle Scholar
  11. Souza Lima VM, Abrahão RA (1982) Two practical examples of numerical approaches for solving discontinuity problems in dam design. Int J Numer Anal Methods Geomech 6:461–481CrossRefGoogle Scholar
  12. Souza Lima VM, Abrahão RA, Pinheiro R, Degaspare JC (1982) Rock foundations with marked discontinuities. Criteria and assumptions for stability analyses. 14th. ICOLD congress, Rio de Janeiro, BrazilGoogle Scholar

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© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.São PauloBrazil

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