Challenges in the design of hydraulic steel structures and powerhouses: Fid-Bau Portal

Challenges in the design of hydraulic steel structures and powerhouses

Krueger, K. / Lechner, A.

The present paper reports about challenges with respect to the overall structural safety but also about erection and assembly restrictions that occurred in the design and construction of hydraulic steel structures and powerhouses in different hydropower projects at Voith Hydro. This paper is dedicated to new installations and to the refurbishment of existing structures as well. Challenges regarding the structural design of several penstocks with diameters up to 12m comprising straight sections followed by concrete covered miter bends are summarized. As a result of the civil structure optimization, the corresponding miter bend sections were embedded in the surrounding reinforced concrete structure with low coverage height. The load carrying capacity of the miter bends with partial collaboration of the reinforced concrete tructure was assessed in detail. Furthermore safety considerations on large-diameter - but relatively thin - steel inlet-liners installed in one project in Portugal are discussed. Challenges in the design of the hydraulic steel structures were solved with special respect to the structural behavior of the combined thrust collars and stiffening rings, and of asymmetric cones. A further example describes some challenges in modernization business regarding submerged and steel armored dissipation chambers for turbine bypass systems. In the last example Voith assumed full responsibility for the planning and installation of both the mechanical and the electrical components for a shaft powerhouse in Germany. The delivery and installation of the components was restricted due to the limited space in the shaft. Different challenges in the minimization of the powerhouse size and in the optimization of the on-site assembly were mastered successfully.