Nonlinear finite element reliability analysis of Concrete-Faced Rockfill (CFR) dams under static effects


Kartal M. E. , Bayraktar A. , BAŞAĞA H. B.

APPLIED MATHEMATICAL MODELLING, vol.36, no.11, pp.5229-5248, 2012 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 36 Issue: 11
  • Publication Date: 2012
  • Doi Number: 10.1016/j.apm.2011.12.004
  • Title of Journal : APPLIED MATHEMATICAL MODELLING
  • Page Numbers: pp.5229-5248

Abstract

The response of concrete slab on Concrete-Faced Rockfill (CFR) dams is very important. This
study investigates the reliability of the concrete slab on a CFR dam by the improved
Rackwitz–Fiessler method under static loads. For this purpose, ANSYS finite element analysis
software and FERUM reliability analysis program are combined with direct coupled
method and response surface method. Reliability index and probability of failure of the
concrete are computed in the all critical points of the concrete slab by dam height. This
study is also expanded for the reliability of CFR dams including different concrete slab
thickness. In addition to the linear behavior, geometrically and materially non-linear
responses of the dam are considered in the finite element analysis which is performed with
reliability analysis. The Drucker–Prager method and the multi linear kinematic hardening
method are, respectively, used for concrete slab and for rockfill and foundation rock. Finite
element model used in the analyses includes dam–reservoir–foundation interaction. Reservoir water is modeled by the Lagrangian approach. Welded and friction contact based on
the Coulomb’s friction law are considered in the joints of the dam. One-dimensional two
noded contact elements are used to define friction. The self-weight of the dam and the
hydrostatic pressure of the reservoir water are considered in the numerical solutions.
According to this study, hydrostatic pressure, nonlinear response of the rockfill and the
decrease in the concrete slab thickness reduce the reliability of the concrete slab of the
CFR dam. Besides, the CFR dam models including friction are safer than the models including welded contact in the joints.

The response of concrete slab on Concrete-Faced Rockfill (CFR) dams is very important. This study investigates the reliability of the concrete slab on a CFR dam by the improved Rackwitz-Fiessler method under static loads. For this purpose, ANSYS finite element analysis software and FERUM reliability analysis program are combined with direct coupled method and response surface method. Reliability index and probability of failure of the concrete are computed in the all critical points of the concrete slab by dam height. This study is also expanded for the reliability of CFR dams including different concrete slab thickness. In addition to the linear behavior, geometrically and materially non-linear responses of the dam are considered in the finite element analysis which is performed with reliability analysis. The Drucker-Prager method and the multi linear kinematic hardening method are, respectively, used for concrete slab and for rockfill and foundation rock. Finite element model used in the analyses includes dam-reservoir-foundation interaction. Reservoir water is modeled by the Lagrangian approach. Welded and friction contact based on the Coulomb's friction law are considered in the joints of the dam. One-dimensional two noded contact elements are used to define friction. The self-weight of the dam and the hydrostatic pressure of the reservoir water are considered in the numerical solutions. According to this study, hydrostatic pressure, nonlinear response of the rockfill and the decrease in the concrete slab thickness reduce the reliability of the concrete slab of the CFR dam. Besides, the CFR dam models including friction are safer than the models including welded contact in the joints. (C) 2011 Elsevier Inc. All rights reserved.