Abstract: A method of computing the disengagement of concrete face slab is proposed based on contact element deformation analysis to deeply understand the spatial rheological characteristics and disengagement of face slab of high concrete face rockfill dam (CFRD). The computation program of 3D static and rheological analysis for CFRD is developed using FLAC3D platform, and the computation method and program are verified through computation case of Sanbanxi CFRD. The temporal and spatial distribution of the deformation and face slab’s disengaged distance of Sanbanxi CFRD are analyzed by using the proposed method, and the positions and values of face slab’s disengagement are determined. The research findings suggest that the rheological effect of dam body is obviously unevenly distributed in space, which aggravates the disengagement of concrete slab and may cause new void areas under the concrete slab.

Key words: Concrete face rockfill dam (CFRD), spacial rheological effect, disengagement of concrete face slab, numerical method, computation method for contact void