Geological conditions, seepage grouting, and evaluation of piezometer measurements in the abutments of an earth dam

The geology of the abutments of the Bakoyianni earth dam in Greece, and the seepage problems of the abutments are described. The driving of grouting and drainage adits was intended to seal and drain the middle and lower conglomerate layers in the abutments. At both abutments and at the middle conglomerate the piezometric levels are higher upstream from the adits than downstream, while at the lower conglomerate a smaller drop in piezometric pressure is present. The behaviour of the abutments of the dam with a reservoir level at an elevation of 275.51 m is satisfactory, and the same is expected for reservoir levels up to 284 m. Hence, a complete control of the abutment seepage that will contribute to the safety of the dam is under way.