Abstract: An apparatus for span-by-span bridge construction, comprises an elongated girder assembly for spanning between adjacent bridge piers for supporting precast bridge segments during assembly, pier brackets for attachment to a pier shaft, the brackets having rollers for support of the girder assembly for movement between piers, and at least one carriage vehicle for engagement with top rail tracks on the girder assembly, the vehicle moveable between a working position of supporting the bridge segments during assembly of multiple segments and a stowage position.

Abstract: A seismic damping system for a building structure, comprises a foundation for supporting a structure, a fixed anchor disposed in an accessible position centrally of the foundation, and damping members connected between the foundation and the anchor for damping seismic movement of the foundation.

Abstract: Advantageously, the present invention also facilitates a unique method for post-tensioning segmental viaduct structures, for rapid transit use or otherwise, wherein post-tensioning cables do not follow load diagrams but instead follow uniform paths through each viaduct segment. In this way, each viaduct segment need not be specially fabricated to accommodate uniquely positioned cables.

Abstract: A rapid transit viaduct system includes a central load bearing body having a pair of lateral platform structures mounted on opposite lower side portions thereof for carrying one or more rapid transit vehicles on either side of the central load bearing body. The viaduct system further includes vertically extending piers positioned below and supporting the central load bearing body. Additionally, a central station platform can be formed wherein some of the precast concrete viaduct segments are vertically divided and spaced apart a selected distance. A plurality of spacer blocks are disposed between the spaced apart viaduct segments, and a plurality of platform slabs are disposed between the spaced apart viaduct segments, above the spacer blocks, to form a station platform.

Abstract: A rapid transit viaduct system includes a central load bearing body having a pair of lateral platform structures mounted on opposite lower side portions thereof for carrying one or more rapid transit vehicles on either side of the central load bearing body. The viaduct system further includes vertically extending piers positioned below and supporting the central load bearing body.

Abstract: A bridge construction system includes a first independent longitudinal truss positioned over a first bridge span, a second independent longitudinal truss positioned over a second bridge span, a gantry movably mounted on said trusses, the gantry having a first leg mounted to the first truss and a second leg mounted to the second truss, the gantry being drivable along the first and second trusses, a gantry drive for controllably driving the gantry along the trusses, a transverse trolley movably mounted on the gantry, the trolley being drivable along the gantry in a direction generally transverse to the longitudinal trusses, the trolley including a winch for lifting and carrying bridge components to be positioned along the bridge spans over which the longitudinal trusses are mounted, the trolley being selectively positionable over each of the bridge spans, and supports for mounting the longitudinal trusses to bridge components disposed along each of the bridge spans.