Stress-Strain Analysis of a Concrete Dam in Predominantly Anisotropic Residual

M.F. Leão, M.P. Pacheco, B.R. Danziger

Article

Soils and Rocks, São Paulo, 41(2): 171-178, May-August, 2018 | PDF


Abstract

Studies of foundations for dams should take into account the study of the behavior of the rocky mass, primarily the stresses and strains expected during the construction and post-construction period. When these structures are supported on sound rock, the use of concrete dams is favored. However, when the foundation is made up of soil or soft rock, earth dams are the most commonly employed technical solution. The study investigates a concrete-gravity dam in the Dominican Republic, with a foundation comprised of alternating horizons of residual soil and weathering soft rock, presenting marked anisotropy and the presence of relict structures. A high incidence of discontinuities gave rise to a more detailed study of the stress-strain behavior of the foundation, taking into account the discontinuity attitudes and the results of direct shear tests carried out parallel to and orthogonal to the discontinuities. By means of 2-D finite element simulations, an anisotropic constitutive model was adopted (the Jointed Rock Model-JRM) capable of modeling up to two preponderant discontinuity directions. The numerical analyses clearly showed the utility of the model in the selection of foundation reinforcement options, in this case through the use of cut-offs to increase the stability conditions.


Submitted on December 14, 2017; Final Acceptance on July 4, 2018; Discussion open until December 31, 2018. DOI: 10.28927/SR.412171