Full-Span Precasting of High-Speed Railway Bridges

Medium-span prestressed-concrete bridges are the backbone of high-speed railway projects. The 113-km Beijing-Tianjin route in China includes 100 km (88%) of bridges, the 1318-km Beijing-Shanghai route includes 1140 km (86%) of bridges, the 904-km Haerbin-Dalian route includes 663 km (73%) of bridges, and the 995-km Wuhan-Guangzhou route includes 402 km (41%) of bridges. More than 35.000 spans for high-speed railway bridges have been recently built in China, and large investments in railway infrastructure have been made in Europe, Japan, Korea and Taiwan as well.

Full-span precasting is a competitive construction method for large-scale railway bridge projects. It offers rapid high-quality construction with minimized labor demand and repetitive casting processes in factory-like conditions, and the spans are cast, transported and positioned all year long in almost any weather conditions.

In 17 pages, the eManual explores the organization of large-scale precasting facilities designed for just-in-time delivery of precast spans. It explains how to optimize the productivity of casting cells and rebar jigs, the pros and cons of span post-tensioning vs. pre-tensioning and hybrid prestressing systems, and the organization of the stockyard in relation to the span curing time at delivery.

• Introduction
• Full-span precasting of high-speed railway bridges
• Tire trolleys and span launchers
• Portal carriers with underbridge
• References

The eManual explores the use of portal carriers with underbridge and span launchers fed by tire trolleys for transportation of precast spans on the completed bridge and top-down placement. It compares loads, kinematics, performance, productivity, structure-equipment interactions and span curing time at delivery of the two solutions, and explains how to choose the most appropriate span delivery method in relation to the length and weight of the precast units, the length and number of bridges to erect, the presence of tunnels and crossover embankments along the delivery routes, and the area available for the span stockyard.

The eManual is an essential tool for bridge owners, designers and construction professionals interested in the planning, design, design-build bidding and construction of large-scale railway bridge projects.