Engineering geological and geophysical investigation at the dam site, Cine/Turkey

Abstract

Cine Dam in South West Turkey will be the first major roller compacted concrete (RCC) dam in Turkey and with the height of 135 m one of the highest in the world. When completed it will perform a number of functions such as water supply, power generation and flood control. Excavation works of dam foot print area are almost completed. The dam is located along a narrow section of the Cine river valley. The cross section along the designed dam axis shows a slightly asymmetrical V-shaped profile, with a steeper left than right bank. The area of Cine dam is dominated by gneiss bedrock, which belongs to the Menderes complex. Foliated augen gneiss prevails, with subordinate massive gneiss beds of more homogeneous texture and highly foliated and intensively sheared gneisses with micaceous schists. The rock mass is gently folded, intensively jointed and locally intensively faulted with the most prominent faults dipping almost vertically and persisting several kilometres. Within the faults and adjacent to them the rock mass is largely disintegrated and locally rich in kaolin. Grain sizes in the core zones of faults are dominated by sand to silt. Site investigation for Cine Dam was developed and executed in several phases. Main aim of the geophysical investigation in the dam site area is to define the boundary of the engineering geological units, location of fault zones, which are covered by slope debris and soils, dynamic elastic parameters of the materials in the core zones as well as in the damage zones of the faults, velocities and dynamic elastic parameters of the soil and rock mass to be encountered at both side of the dam foot print area. Geophysical investigation was correlated with the core drill holes, which were carried out during same investigation campaign, and geological mapping results.