Three-dimensional numerical analysis of concrete-faced rockfill dam using dual-mortar finite element method with mixed tangential contact constraints.

Concrete-faced rockfill dam (CFRD) is a popular alternative to traditional dam types in the last two decades. The modelling of CFRD involves complex multi-body contact and strong geometry and material nonlinearities. We present a numerical approach for the modelling of CFRDs in this paper. Based on the dual-mortar finite element method, the presented approach considers different parts of rockfill and all concrete slabs as independent deformable continuum. The multi-body contacts are modelled using Lagrange multipliers with a weak form segment-to-segment contact strategy. To alleviate instability induced by strong geometry nonlinearity in the slab-slab contact, we propose a mixed type of constraints for the tangential contact. A general transformation scheme is introduced to simplify the implementation of contact constraints. Three-dimensional analysis of Tianshengqiao-1 CFRD is performed. The nonlinear and time-dependent deformation of the rockfill is considered. We study the influence of the rockfill deformation on the reliability of the concrete face. Three major concerns of the face, that is, the axial compression, the slab-slab separation and the face-rockfill separation, are discussed in detail. The numerical results are compared with data from in-situ observation. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]