A longitudinal modular system with boards (3) for underpass bridges for installation of two tracks for railway circulation in which the board (3) is placed between two consecutive piers (4) and comprises a pair of longitudinal beams (1), which themselves comprise a lower wing (2c), for supporting on the piers (4), a core (1b) and an upper wing (1a); and a plurality of transversal slabs (2) that are attached to the lower wings (2c) of the longitudinal beams (1), thus forming a

U-shaped configuration, where the length of the longitudinal beams (1) is essentially similar to the span between two piers (4), and the configuration of the board (3) has a transversal, U-shaped section such that the railway circulates inside said U shape. The invention also describes the method for constructing same.

A precast concrete beam is provided in construction of a long span bridge structure. The beam is formed of a plurality of aligned modular elements each formed of prestressed UHPC mix as a unitary body. The UHPC mix includes discontinuous fibers distributed randomly throughout a concrete matrix. Each modular element is aligned modular and connected by an epoxy grout to adhering adjacent element joints. Finally, post-tensioning of the entire beam reinforces and affixes the plurality of aligned modular elements into a single long span beam.

A precast concrete girder including a substantially planar web extending longitudinally between ends of the girder; a pair of flanges formed integrally with the web, each flange extending laterally from an elongate edge of the web and extending longitudinally between the ends of the girder so as to define a structure engaging surface of the girder; and a plurality of diaphragms formed integrally with the web and the flanges, each diaphragm spanning laterally between a side of the web and one of the flanges, wherein the diaphragms are spaced apart along the girder to thereby support the flanges.

A precast concrete girder including a substantially planar web extending longitudinally between ends of the girder; a pair of flanges formed integrally with the web, each flange extending laterally from an elongate edge of the web and extending longitudinally between the ends of the girder so as to define a structure engaging surface of the girder; and a plurality of diaphragms formed integrally with the web and the flanges, each diaphragm spanning laterally between a side of the web and one of the flanges, wherein the diaphragms are spaced apart along the girder to thereby support the flanges.

A precast concrete beam A beam for use in construction of a long span bridge structure comprising: a reinforcing member having a geometric configuration selected from a group consisting of: a “U” tub beam with composite deck system; a decked I-beam; and an adjacent box beam; said geometric configuration formed of a UHPC mix having: an initial compressive strength, f′.sub.ci=10.0 ksi; a compressive strength at service, f′.sub.c=17.4 ksi; a modulus of elasticity of concrete, E.sub.c=6500 ksi; a residual rupture stress, f.sub.rr=0.75 ksi; and a concrete unit weight, w.sub.c=0.155 kcf; and
said UHPC mix further comprises a plurality of discontinuous fibers distributed randomly throughout a concrete matrix, said plurality of discontinuous fibers formed of a material selected from the group consisting of: steel; polypropylene; nylon; polyvinyl alcohol; polyolefin; polyethylene; polyester; acrylic; aramid; carbon; silica glass; basalt glass; glass fiber-reinforced polymer; and basalt fiber-reinforced polymer.

A combined plate-beam unit analysis method considering a residual stress effect of an orthotropic plate, which is used for analyzing an orthotropic steel bridge deck welded by a top plate of a bridge deck and a trapezoidal rib, the top plate of the bridge deck is analyzed by a flat shell unit, while each sub-plate forming a trapezoidal rib is analyzed by a plate-beam unit. The welding residual stress of a top plate and a trapezoidal rib is obtained by a residual stress self-balancing condition, and the initial deformation of a top plate and left and right web plates of a trapezoidal rib is obtained by the stress-strain relationship. The combined plate-beam unit analysis method has the advantages of less freedom and high calculation accuracy, so it is especially suitable for structural analysis of the trapezoidal rib orthotropic plates.

A combined plate-beam unit analysis method considering a residual stress effect of an orthotropic plate, which is used for analyzing an orthotropic steel bridge deck welded by a top plate of a bridge deck and a trapezoidal rib, the top plate of the bridge deck is analyzed by a flat shell unit, while each sub-plate forming a trapezoidal rib is analyzed by a plate-beam unit. The welding residual stress of a top plate and a trapezoidal rib is obtained by a residual stress self-balancing condition, and the initial deformation of a top plate and left and right web plates of a trapezoidal rib is obtained by the stress-strain relationship. The combined plate-beam unit analysis method has the advantages of less freedom and high calculation accuracy, so it is especially suitable for structural analysis of the trapezoidal rib orthotropic plates.

Improved tub girders and related manufacturing methods are provided, such as for example for use in road construction in connection with concrete bridges. Disclosed improved tub girders may include upper flanges that extending inwardly or outwardly. Disclosed improved tub girders may be provided with camber along the length of the girders. Ends of the disclosed improved tub girders may be provided with diaphragms. Disclosed improved tub girders may include a base section including one more access ports for enabling inspection of the interior of the girders after installation. Disclosed improved tub girders may include a plurality of stud members extending upwardly from upper flanges for engaging with a concrete bridge deck. Disclosed tub girders may be providing with a coating, such as galvanized, aluminized or metalized, to fight corrosion and extend life and limit need for inspection.

Improved tub girders and related manufacturing methods are provided, such as for example for use in road construction in connection with concrete bridges. Disclosed improved tub girders may include upper flanges that extending inwardly or outwardly. Disclosed improved tub girders may be provided with camber along the length of the girders. Ends of the disclosed improved tub girders may be provided with diaphragms. Disclosed improved tub girders may include a base section including one more access ports for enabling inspection of the interior of the girders after installation. Disclosed improved tub girders may include a plurality of stud members extending upwardly from upper flanges for engaging with a concrete bridge deck. Disclosed tub girders may be providing with a coating, such as galvanized, aluminized or metalized, to fight corrosion and extend life and limit need for inspection.

A jacking force transfer method to compress prefabricated deck units and to tension bridge girders. Prefabricated deck units are placed on top of bridge girders. Relative motion between girders and deck units is permitted along the direction of bridge girders while deck units are first installed. Subsequently, an end deck unit is made composite with the girders while jacking brackets are installed on top of the deck unit on the other end of the bridge. Hydraulic jacks react with jacking brackets to introduce a longitudinal compression in prefabricated deck units and, at the same time, a tension in the girders.