Karstic limestone problem at Kavsak dam site and reservoird area

Abstract

The paper presents the foundation investigations carried out at Kavsak dam which was proposed for power generation as approximately 200 m in height on the Seyhan river over relatively karstic limestone. Two alternative sites were investigated. Both dam sites were found consequently to be infeasible due to the water leakages likely to occur through the limestone which occupies a long stretch of the dam site and reservoir area. The exploratory boreholes and field studies revealed that the karstification had developed along structural features such as joints and faults. Karstification was found to extend down to a depth of 200 m below the Seyhan river level. The geological studies showed that it would be necessary to establish a safe grout curtain to prevent any possible leakage through limestone in an approximately 5.5 km long portion on the right bank of reservoir area starting from the dam site. This type of treatment was considered to be uneconomic. As a result of comprehensive investigations carried out at the dam site and reservoir area the project was abandoned and new dam site alternatives were selected at further upstream portions of two tributaries.