Design of the Top Chord of Stressed-Arch Frames

摘要

Stressed-arch frames are characterized by a post-tensioning procedure which isused to erect the frames from an assembled configuration at ground level to a final erected shape. During the erection process, the top chord becomes curved and is usually stressed into the inelastic range. Consequently, the strength of the erected frame under service loading cannot be assessed rationally using conventional elastic or plastic methods for the analysis and design of steel structures. The purpose of the report is to examine in detail the provisions of specifications and standards worldwide for the design of the top chord of stressed-arch frames, and to propose and validate a simple design procedure. In particular, the irrationality of design based on conventional elastic and plastic methods, and, alternatively, the rationality of design based on advanced analysis as described in the Australian Standard for Steel Structures, AS4100-1990, is identified. Aside from the Australian Standard, the other standards and specifications considered in the report are the American Institute of Steel Construction and American Iron and Steel Institute Load and Resistance Factor Design Specifications, the Canadian Standard for Steel Structures and the proposed Eurocode 3.