Three-Dimensional FEM Parametric Analysis of Stiffened Steel Liners in Hydroelectric Pressure Tunnels

Abstract

The availability of tools for safety evaluation of a pressure liner is a relevant issue in both structural and hydraulic engineering. Parametric studies for assessing the stability of stiffened steel liners in hydroelectric pressure tunnels, as well as practical design guidelines, are presented in this paper. First, a review of the design methods for steel liners is outlined, with certain key aspects for the critical buckling load assessment of a steel pressure liner being considered. The methodology involves three-dimensional (3D) nonlinear finite element modeling procedures, in which liner constraining and the presence of stiffeners are taken into account. In addition, both large displacements and a surrounding elastic medium are assumed in the model.