Narrow span foot bridge - consists of hollow U-shaped girder made of welded metal plates with lengthwise trough shaped reinforcing girder underneath

摘要

The hollow girder of flattened U-shaped cross-section is preferably cambered and formed of metal plates welded together. The bottom of the U forms the tread surface (1) and the sides of the U (2) form the balustrade and hand-rail (5). A central, lengthwise trough-shaped girder (3) reinforces the structure and is welded to the underneath of the tread surface (1), and imparts flexural strength to the floor. Crosswise welded metal flanges (4) protrude outwards, to impart rigidity to the U-shaped structure. The depth of the flanges (4) beneath the flooring equals that of the central trough-speed girder. The footbridge does not exceed three-and-a-half metres in width and forty metres in span. The side balustrades are between 0.80 and 1.0 m in height.