Significance of Construction Stage Analysis on the Initial Configuration of Concrete Faced Rockfill Dams

Abstract

AbstractRockfill dams bear large water bodies; therefore, assessment of the stability of these structures is crucial. Different approaches have been followed by previous researchers to numerically analyze concrete faced rockfill dams. A proper guideline to define the initial configuration when developing finite element models for large-scale analysis like seismic analysis is not available. Therefore, in this research a 3-dimensional finite element model of the Kotmale dam has been developed using MIDAS FEA NX software, and the construction sequence has been adopted in the static analysis. In a CFRD dam, a large volume of rockfill material is used; therefore, it is crucial to select the appropriate material model. The Duncan and Chang EB model was selected based on previous research to model the material behavior of the rockfill and the transition layers. Linear elastic model was used for modeling of the concrete face of the dam. The bedrock was modeled using linear elastic material models. The results are compared for two different analysis conducted with construction stage analysis and without construction stage analysis with the actual observed deformations of the dam. The results agree well when the construction sequence is considered; furthermore, the deformation shape is completely different for the two cases.KeywordsConcrete faced rockfill dams3D Dam modelConstruction stage analysis