doi:10.3850/978-981-08-7920-4_S2-A16-cd

ABSTRACT

Spatial structures have been used by structural engineers as an economical system to cover large areas. These systems, which are generally composed of linear structural members interconnected to each other, have also been popular in the architectural community due to their intriguing geometrical configurations as exposed structural systems. Flat double-layer grid (FDLG) system is a type of spatial structure consisting of linear members forming a top and bottom grid layer interconnected by bracing or web members. This paper presents a study of the structural behavior of square-on-square offset steel FDLG subjected to various loading conditions. It investigates several issues as related to the analysis and design of these systems such as effects of load intensity, number of modules, span/depth ratio, cantilever ratio, member end rigidity and support types, bay continuity, group sizing and method of design on the structural efficiency. From the results of this study it is concluded that the load intensity does not have any significant effect on the optimum span/depth ratio. In addition, conclusions are made on the optimumspan/depth ratios based on the support locations, efficiency of interior vs. exterior bays, effects of cantilever, and partitioning for the design of the square-on-square offset FDLGs.

Keywords: Space frames, Spatial structures, Double-layer grids, Square-on-square offset, Structural efficiency, Optimum span-depth ratio, Cantilever, Partitioning, LRFD, ASD, Load intensity.

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