B R I D G E B U I L D E R
 NRS AS: 10/8/2008 Page hit #  9,014 Enhanced economic performance 

THE IN-SITU FREE CANTILEVER METHOD



Enhance the economic performance of bridge projects


The "Bridgebuilder" formtraveller:
The "Bridgebuilder" formtraveller system was invented in 1970 and today it is acclaimed for enhancing the cost-effectiveness of bridge projects world-wide. NRS has continually improved the Bridgebuilder in collaboration with major contractors. The system is lightweight, versatile and easy to assemble and operate. Rolling forward on rails, the system can be reset quickly and easily.

Where to use the Bridgebuilder:
The Bridgebuilder is used for free cantilever construction of post-tensioned boxgirder - and cable-stayed concrete bridges. Engineering to international standards, the system provides an exceptionally rigid formwork, with a maximum deflection of less than 25 mm at full loading.

Standard convertible Bridgebuilders:
The Standard Bridgebuilder is designed for a maximum segment length of 5 m and load capasities (concrete and formwork) varying from 100 tons to 400 tons. The steel weight depends on the cross-section of the bridge in question, but will normally vary from about 25 tons to 65 tons correspondingly. The Standard Bridgebuilder may be adapted to suite almost any cross-section, and is easily adjustable during operation to variations in segment length (up to 5 m), section height, web thickness, and deck width.

Tailored Bridgebuilders:
The Bridgebuilder may be tailor-made for segment lengths beyond 5 m and other extreme conditions. Alternatively it may be designed for shorter lengths where the maximum segment length is less than 5 m, and there is a requirement to reduce the weight of the Bridgebuilder for a particular application.

Precast Segmental Bridgebuilders:
The Precast Segmental Bridgebuilder is designed for a maximum precast segment lenght of approx. 3 - 5 m and load capacities between 100 and 300 tons. It is equipped with two hoists for lifting the precast segments as well as for adjusting the crossfall. A manipulator permits adjustment of the longitudinal fall and hydraulic cylinders launch the device forward.
The Precast Segmental Bridgebuilder can be adapted to almost any new cross section for future projects.

Bridge design and deflection control:
A variety of technical advice is available in connection with cantilever-bridges, covering in particular the following subjects:


Tender phase:
Complete bridge design
Alternative design
Optimum design of cross-section
 
Construction phase:
Optimum design of concrete and reinforcement
Deflections, calculation and control
Time saving working procedures
Post-tensioning
Concrete, grouting


The Bridgebuilder features:
  • Lightweight:
    The use of rectangular hollow sections in the main structural components and recoverable high strength bars in all stays and ties reduces the total steel weight to a minimum.
  • Flexible design:
    The Bridgebuilder may be adapted to almost any cross-section and is easily adjustable during operation to variations in segment length, box height, web thickness, deck width and road alignment (gradient, curvature, super-elevations).
  • Small deflections:
    The vertical deflection at the front of the Bridgebuilder is less than 25 mm at maximum load. Formwork beams are designed for a maximum deflection of 1/400 of their length.
  • Easy assembly:
    One Bridgebuilder may be assembled in one week. Rolling forward on rails, the reset time is short.

VIEW SPECIFIC DETAILS BY HITTING THE LINKS BELOW:

Technical principle & working cycle:
Cross-member for installation on small pierheads:
Precast Segmental Bridgebuilder:
The world's 10 longest free cantilever concrete bridges:
For more information: See Our Projectgallery