ABSTRACT
This chapter explores different options to understand structural and spatial implications of different layouts, roof forms, and cross-sections of trusses. Train stations were the initial testing grounds for the first long span trusses and many contemporary stations continue to use trusses as their primary structural systems. Triangulated panels provide efficient means of force distribution within a self-stabilizing geometry; they make trusses light and stiff. Significant synergistic advances in material technology, fabrication methods, and analytical tools have improved the ways trusses can be integrated into long span structures; under certain conditions, trusses can span over 500ft. The girder truss’s panel proportion is based on the distance between purlins and the depth of the girder, which is based in turn on its span. Flat trusses, like flat beams, suffer structural disadvantages by their geometry–particularly when compared to truss forms that curve or arch. The logical architectural and structural extension of the bowstring and crescent shapes would be a complete arched truss.
