Dewatering methods on the site of regulator structures of Ceyhan Hydroelectric Power Plant Project (Cevdetiye-Osmaniye)

Ceyhan Hydroelectric Power Plant (HEPP) Projects, consists of two plants named Oşkan and Berkman for energy generating purposes. The permeability of alluvium material covering the flysch unit at Oşkan HEPP is 10-2-10-3 m/sn, which is high permeable. The alluvium material at Berkman HEPP is around 10-3-10-5 cm/sn values. For the control of the possible leakage on the alluvium soil around the construction zone, Jet Grouting process involving concrete columns to make barrier was applied. It was seen that, the application didn?t achieve the desired permeation levels. For the Dam axis and at the spillway, plastic concrete was applied by Slurry Trench process to form an impermeable layer.The techniques used are observed with details and selection reasons. The laboratory result of the used mixtures and technical specifications are also explained in the scope of this research.The properties of the soil, which impermeable process applied, will guide for the cases with similar soil characteristics as a result of this research.The geo-technical works made before the application also explained with details.