Entnahmebauwerk Kohlekraftwerk Wilhelmshaven - Planung und Ausführung eines außergewöhnlichen Einschwimm- und Absenkverfahrens

Intake riser for a coal-fired power station in Wilhelmshaven - Design and construction using an extraordinary floating-in and submerging method

At present, a coal-fired power station is being built adjacent to the River Jade in Wilhelmshaven. The cooling water for the whole plant will be taken from the Jade by means of two intake structures. In order to construct the intake structures, it was decided to use an alternative proposal involving floating-in and submerging of the structure. For this, both the intakes and buoyancy tanks were incorporated in one structure . The first section of the intake structure was constructed in a dry dock, and subsequently towed on the open sea to the port of Wilhelmshafen. The structure was then completed in several phases in the port of Wilhelmshaven, in some phases floating, and in others supported on a temporary pile foundation. In the completed condition the structure was buoyant, but however unstable. Therefore coupled Flexifloat-units were used for additional buoyancy during the tow to the final location, with strand jacks installed for raising and lowering the structure. After submersion of the intake structure, the joint between the base slab and formation level was sealed using grout. The cooling water pipelines were then connected, the ballast compartments were filled with sand, and scour protection was installed.