GB423926A - Improvements relating to bridges of the braced girder type - Google Patents

Abstract

423,926. Bridges. HAMILTON, A. M., 30, Pond Place, South Kensington, London. May 12, 1933, No. 13862. [Class 20 (i)] Relates to bridges and like structures of the I kind in which the principal truss members are composed of identical elements of angle section, the number of elements in each individual member being dictated by the load which that member will have to carry. According to the invention, those members which are composed of three or more elements have at least two elements arranged with overlapping flanges, the unlapped flanges extending parallel and in the same direction. In one construction, a Warren girder bridge, Fig. 5, has the top and bottom chords and the bracing members built up of standard angle-bars of rolled steel. The members a, b consist of one and two angle-bars, respectively, while the members c, d, carrying heavier loads, consist of three or more anglebars with their flanges arranged as above described. Adjacent ends of the members are interconnected by fish-plates 6 and pentagonal gusset plates 5, Fig. 7. The floor 13 is carried by channel section floor beams 7 which are bolted to the flanges 8 of the gusset plates. In a modification, the floor is carried adjacent the upper chord members. In another modification, a bridge with double trusses, Fig. 9, has each member k formed of two groups of elements. Each group, forming a double member, is connected to separate gusset plates which are braced by batten plates 11 and by the floor beams ; intermediate batten plates 12 are also provided for bracing purposes. Further modifications are described, applied in a bridge of greater depth and in a multiple truss structure designed to carry a railway. The flanges of the angle-bars may be of equal or unequal width. Various manners of arranging the anglebars of single and double members are illustrated. Specification 423,996 is referred to.