Using artificial fill under the plinth of a CFSGD: the case of Arkun dam

Arkun dam is a 140 m-high concrete face sand-gravel dam (CFSGD) in northeast Turkey. An opening was found between the plinth and the face slab at the perimeter joint of the dam during impounding. This was caused by the relative difference between the total settlement of the face slab and the plinth. As a solution, the plinth of the dam was placed on a homogeneous, semi-pervious and low compressibility artificial sand-gravel fill, to mitigate the formation of relative deformations. The idea was to leverage the fill’s low compressibility to reduce the total settlement difference of the face slab and the plinth. This paper examines the effectiveness of the design and construction using artificial fill by comparing the calculated openings between the plinth and the face slab at the perimeter joint and data collected from the dam monitoring instruments.