PREFABRICATED BRIDGES IN CZECHOSLOVAKIA

The main bridge types used in road construction in Czechoslovakia are bridges with small spans, bridges for grade-separated crossings on traffic routes and urban main streets and bridges constructed over deep valleys. Bridges with span lengths of up to 30 M predominate in the area of motorway construction. A doubling in bridge construction, with a resultant increase in the use of prefabricated structures is foreseen for the next five year plan. The paper describes beam types and prefabricated structures developed up to now: (1) hollow prestressed concrete box girders for span widths of 9 M to 18 M; (2) wide flange i-sections manufactured in elements, assembled on site and stressed together to form beams with span widths varying from 21 M to 30 M; (3) prefabricated sections of reinforced concrete with span widths of 3.6 M to 9 M; (4) wall and slab elements for frames with span widths of 3 M to 7 M; (5) arch sections for use in the construction of parabolic arches for culverts. Hollow concrete box girders in sections are used for the construction of bridges over motorways. In addition, the paper describes prefabricated columns, methods of successive cantilevering, bridge accessories and stressing techniques. /TRRL/