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Title: Analysis of embankment dams : computational aspects
Author: Maranha, J. R. M.
Awarding Body: University of Wales Swansea
Current Institution: Swansea University
Date of Award: 1997
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Aspects of the numerical simulation of the static behaviour of embankment dams were investigated in this thesis. Different stress updated algorithms were compared and the implicit backward Euler scheme was found to be the most accurate and robust. Particular emphasis was given to the use of a tangent modulus matrix consistent with the backward Euler scheme in the context of the Newton-Raphson method of solution of the nonlinear finite element equations. This combination was found to provide a robust algorithm. A closed form solution and a numerical procedure to evaluate the consistent tangent modulus matrix were described. The implications of using 2D and 3D formulations of elasto-plastic models were analysed. In particular 3D version of Tresca, Mohr-Coulomb and the critical state model were compared to their respective 2D versions. A robust stress update algorithm for the Mohr-Coulomb model formulated in principal stresses was presented. The comparisons were made by means of numerical examples that included: a rigid smooth strip footing, a purely cohesive slope and the construction of a dam. A 3D analysis of a hypothetical dam located in a v shaped narrow valley was made in parallel with a plane strain analysis of the same dam and the arching effect evidenced. A framework for incorporating plastic anistropic behaviour into elasto-plastic constitutive laws for soils based on a second order tensor was described. A rotational anistropic extension of the 2D version Tresca model and a shear anisotropy extension of the 2D version of the critical state model were presented and aspects of their performance illustrated by means of numerical examples. An investigation of an algorithm to model collapse settlement of soils having a general constitutive law was conducted. A version of the algorithm particularly adequate for the displacement based finite element method was presented. A back analysis of an actual dam (Beliche dam) incorporating an elasto-plastic model (c.s.m.) and collapse settlement was performed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available