Analysis of an arch-gravity dam with a horizontal crack

A horizontal crack first appeared along the downstream wall of the upper ga llery of an arch-gravity dam after 25 years of operation. Since then, the c rack has extended over the whole length of the upper gallery and the crack opening has been continually increasing. This has been, accompanied by an i rreversible displacement of the dam crest towards the upstream side. This p roblem was investigated with the help of a three-dimensional finite-element model of the dam-foundation system. The results of an extensive finite ele ment study show that such behaviour can be satisfactorily explained with an assumption of a gradual increase of the volume of the mass concrete due to alkali-aggregate reactions (AAR). The testing of the mass concrete used in the dam also indicates a substantial potential for the occurrence of such reactions. (C) 1999 Elsevier Science Ltd. All rights reserved.