Erection of Precast Beam Bridges with Twin-Truss Launchers
Precast beams are often the least expensive solution for prestressed-concrete bridges with 20-60m spans. When good access to the deck is available throughout the bridge and the beams can be delivered on the ground under the span to erect, ground cranes usually give the simplest and most rapid erection procedures with the minimum of investment.
Tall piers, steep slopes, ground obstructions, crossings of rivers, infrastructure or wetlands, and marine operations suggest the use of self-launching gantries for the erection of precast beams delivered on barges or on the completed bridge through the abutment.
With extensive illustrations, the eManual explores configurations, operations, loads, kinematics, performance, productivity and structure-equipment interactions of twin-truss self-launching gantries for span-by-span erection of precast beam bridges.
In 20 pages, the eManual provides exhaustive coverage of the topic. It compares the use of castellated-web box girders and modular trusses with shear-pin connections for the main structural elements of the gantry, examines the span cycle time for beam delivery on the ground and on the deck with progressive advancing of the loading bay, and explores the loads and stiffness interactions to consider for the design of bridge piers and bent caps.
- Twin-truss beam launchers
- Loading, kinematics, typical features
- Support, launch and lock systems
- Performance and productivity
- Structure-equipment interaction
The eManual is an essential tool for bridge owners, designers and construction professionals interested in the design, design-build bidding and construction of precast beam bridges on difficult terrains.