Stress-Strain Analysis of Different Concrete Cut Off Wall Connection Systems Case Study: Karkheh Storage Dam

The concrete cut off wall is usually used to control the seepage through the foundation of earth dams. It is usually made of plastic concrete. It can be connected to the core of the earth dam using different connection systems. The difference between cut off wall and core material results stress concentration in the connection zone. In fact the main cause is the large difference between stiffness of the cut off wall concrete and clayey core of the dam. This makes the stress-strain behavior complex in the connection zone. In the present study, six different details for the connection system of the cut off wall to the earth dam core were identified. The Karkheh storage dam in Iran with a plastic concrete cut off wall was selected as the case study for investigation of the behavior of different connection systems. The connection systems were modeled and the stress-strain behavior in connection zones was analyzed at the end of dam construction and steady state seepage through the dam. Eventually, the most appropriate connection with the best stress-strain distribution was determined. According to the results the stress strain behavior of different types of cut off connection systems are different. Indeed, the kind of connection between the cut off wall and the core influences the stress-strain distribution in the connection zone drastically. According to the results, the system No. 2 (thick concrete slab at the base level of the core) causes a better stress-strain distribution compared to the other methods of cut off wall connection with the core