A STRUCTURAL ANALYSIS FRAMEWORK FOR CONCRETE FACED ROCKFILL DAMS

• Main Author: Quiroz, Juan E.
• Other Authors: Modares, Mehdi
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2013
• Subjects: Barra; Kárahnjúkar; Iceland
• Online Access: http://hdl.handle.net/10560/3262; http://repository.iit.edu/islandora/object/islandora%3A6876/datastream/TN/view/A%20STRUCTURAL%20ANALYSIS%20FRAMEWORK%20FOR%20CONCRETE%20FACED%20ROCKFILL%20DAMS.jpg

Concrete Faced Rockfill Dams (CFRD’s) are commonly built around the world. As energy demands soar and construction methods evolve, the interest for construction of CFRD’s with larger heights has increased tremendously. However, because of construction of higher CFRD’s, some dams have experienced considerable fractures at the concrete faces. Well known cases include Campos Novos (Brazil), Barra Grande (Brazil), and Mohale (South Africa), where in some instances these cracks have led to dewatering of the reservoir to allow for the concrete slabs repairs. The development of these fractures may be attributed to the highly deformable rockfill body. In general, the state-of-the-art design of CFRD’s is mostly based on common practice rather than rigorous analysis procedures. And as such, cracking problems because of deformability of the rockfill may not be properly predicted unless a detailed analysis is performed. In this work, a new framework for analysis of CFRD’s is developed that is capable of predicting the possible concrete-facing failure. As a part of this framework, a comprehensive non-linear finite element analysis (FEA) scheme is developed to model the construction sequence, the contact interaction between the concrete facing and the rockfill body, and the impounding of the reservoir. As a case study, using the developed framework, the Kárahnjúkar CFRD (Iceland, 198m height) is analyzed, the results are validated by the field measurements, and mitigation measures suggestions are provided. This methodology, based on the results of the investigation, provides guidelines and establishes a framework for analysis of CFRD’s that can be used for design purposes. Keywords: CFRD, Concrete Faced, Rockfill, Dam, Finite Element Analysis. PH.D in Structural Engineering, December 2013