Patent classifications
E01D2101/32
COMPOSITE RCC DECK AND PRESTRESSED PARABOLIC BOTTOM CHORD UNDERSLUNG OPEN WEB STEEL GIRDER BRIDGE SUPERSTRUCTURE
Composite decks increase bridge strength and stiffness. Prestressed composite open web steel girder has added advantage of high strength cable support. Results of typical 125 m span bridges having heights of 9.0 m, 10.0 m and 12.5 m, and another 50.0 m span and 2.5 m height are given. Member stresses and bridge deflections during erection remained safe. Average steel off take for the 125 m bridge is 2.65 t/m and for the 50 m span bridge it is 1.77 t/m for limiting live load deflection of Span/800. Its reserve strength is 3.2 times service condition live load.
The girders are panel wise workshop fabricated, assembled at site, jacked up or crane lifted to secure over bearings. Connection of the cross members, and onsite deck casting in parts with stage wise bottom chord prestressing is carried out. Short to long span bridges for single or multiple lanes in road, rail, metro rail, and coastal link projects are feasible.
PREFABRICATED, PRESTRESSED BRIDGE MODULE
A method for making a prefabricated, prestressed module includes arranging one or more steel beams atop a supporting formwork element in a direction transverse to the supporting formwork element and arranging one or more precast deck elements across the one or more steel beams to create a substantially continuous surface. The one or more precast deck elements have pockets for receiving connectors that protrude from the one or more steel beams. The method also includes arranging the supporting formwork element to allow the one or more steel beams to bend into a cambered shape to impart compressive stresses to a bottom flange of the one or more steel beams and tension stresses to a top flange of the one or more steel beams and inserting grout into the pockets to hold the cambered shape and to bond the one or more precast deck elements to the connectors and the top flange.