Abstract: A construction method for simple bridges or continuous bridges using prestressed concrete girder (PSC girder) and precast slabs (PSC slabs) where prestress is applied to the lower portion of the center of the girder. bridges of low clearance and long span are constructed by preventing a loss of prestress due to load of the slabs and relieving excessive compression force generated on the upper edge portion of the center of the girder during the construction of the bridge.

Abstract: A girder bridge protection device. The girder protection device includes a sacrifice member having girders installed on an upper surface of a bridge seat of an abutment or pier to support a bridge floor, a symmetrical main support member connecting two of the girders and having an elongated tubular configuration, and an auxiliary support member projecting from one surface of a center portion of the main support member in a direction perpendicular to an axial direction of the main support member; and a restraining member secured to the bridge seat of the abutment or pier and having an accommodating section accommodating the auxiliary support member such that the auxiliary support member is separated from the accommodating section in a forward and rearward direction and in a leftward and rightward direction, thereby controlling the behavior of the auxiliary support member.

Abstract: Disclosed is a method of constructing partially earth-anchored cable-stayed bridges using a thermal prestressing technique, in which, when a steel girder-type partially earth-anchored cable-stayed bridge is built using a cantilever construction technique, the center of an intermediate span of the bridge is closed with a final key segment using a thermal prestressing technique, thus applying an initial axial tensile force to reinforcing girders of the bridge. To apply the initial axial tensile force to the reinforcing girders while the center of the intermediate span is closed with the final key segment, an appropriate space length required for closure of the final key segment is determined, and both the heating region and the heating temperature of the reinforcing girders according to the initial axial tensile force to be applied to the reinforcing girders during a process of manufacturing the final key segment are determined.

Abstract: A bridge is constructed using simply structured, longitudinal, modular deck sections or cells that are fabricated in a shop and shipped to the jobsite for quick assembly and erection. Each section has generally horizontal upper and lower members and at least one generally vertical member connected between the upper and lower horizontal members. The sections may be C-shaped, Z-shaped, or shallow U-shaped, and are connected in series. The upper and lower horizontal members of each section overlap respectively portions of the upper and lower horizontal members of the adjacent section to form overlapped regions. The connection sections define a plurality of closed cells. Open cells at the ends may be closed using appropriate end section(s) that may be shallow C-shaped or J-shaped. The sections are roll-formed or press braked from metal sheets or plates. The sections are connected together to form a multi-cell box girder bridge module by mating and welding or bolting the overlapped regions.

Abstract: A method of constructing a bridge including forming a concrete slab remote from the bridge, the slab having a side with at least one bolt hole therein, orienting the side of the concrete slab substantially parallel to the side of a girder so that the bolt hole of the concrete slab is aligned with a bolt hole in the side of the girder and connecting the bolt hole of the concrete slab with the bolt hole of the girder using a bracket and a pair of bolts.

Abstract: A modular structure construction and repair system for use in new bridge construction and old bridge repair. The invention comprises a plurality of prefabricated modules which have a plurality of longitudinally extending beams and deck portions molded thereto. The modules are positioned over a plurality of girders so that longitudinal joints are formed above the girder. In the repair of an old bridge, an old section of the bridge deck is removed, and the modules are positioned on the existing girders. The modules are attached to the girders such that a shear connection is provided therebetween. Precompression may also be applied to clamp the sides of adjacent deck portions together. Various embodiments disclose this precompression and the shear connections.

Abstract: A prestressed concrete girder having an adjustable load bearing capacity includes a concrete girder including an upper flange, and at least one non-attached steel wire installed in the upper flange of the girder and extending in a lengthwise direction of the girder. A method of adjusting a load bearing capacity of a bridge using a prestressed concrete girder having an adjustable load bearing capacity including non-attached steel wires capable of being cut at an upper flange is also disclosed.

Abstract: A truss for distributing a maximum bending moment normally occurring at a midpoint region of a girder (430) includes a first truss segment member (505) having first and second ends, a second truss segment member (420) having first and second ends, a third truss segment member (510) having first and second ends, a fourth truss segment member (425) having first and second ends, and a fifth truss segment member (415) having first and second ends. The first end of the first truss segment member (505) is attached substantially perpendicular to the girder at a first location near the midpoint region of the girder and the second end of the second truss segment member (420) is attached to the second end of the first truss segment member (505). The first end of the third truss segment member (510) is attached substantially perpendicular to the girder (430) at a second location near the midpoint region of the girder. The first location is located between the second location and the first end of the girder.

Abstract: A method for constructing a composite bridge superstructure of simple precast elements. According to the method, the bridge superstucture is comprised of one or more prestressed beams aligned substantially parallel to the bridge longitudinal axis. On top of the prestressed beams, there is placed a plurality of full width, precast deck slabs forming the bridge deck, with the precast deck slabs being transversely disposed side by side, with adjacent slabs attached by joints to complete the bridge deck structure. The deck slabs are spaced from the beams by spacing devices, such that a gap is left between the beams and the deck slabs and the bridge deck structure is prestressed separately from the beams. Subsequent to the prestressing of the deck structure and the beams, the bridge deck structure is connected to the beams by a concrete layer cast in situ in the gap between the bottom face of the precast deck slabs and the top face of the prestressed beams.

Abstract: Elongated composite deck sections or panels are formed by pultruding a plastics resin material with multiple layers or mats of glass fibers and longitudinally extending unidirectional fibers to form a base wall integrally connecting upwardly projecting and longitudinally extending tubular ribs. Each rib has opposite side surfaces converging towards the base wall, and longitudinally extending ears project laterally outwardly from the side surfaces. The top surface of each panel is coated with epoxy adhesive, and the top surface of the base wall is also coated with an aggregate of crushed stone. The deck panels are assembled in laterally adjacent overlapping relation to form a permanent composite deck form. A mat of fiber reinforced composite rods are spaced above the deck panels which are surrounded by border forms, and concrete is poured onto the deck panels which positively bond with the concrete.