A temporary walk-through truss bridge was constructed for the CRL project to carry services and provide access over the rail line under construction.
Key Features:
- Walk through truss bridge on two towers.
- Two supporting towers, clad with web forge sheets.
- Walkway raised 1m to accommodate space for extensive service pipes and ducts.
- Service pipes and ducts, along with support towers, were pre-fitted into bridge span.
- Thermal metal spray to SHS truss members.
- Built to NZS5131 and related codes.
Challenges:
- Bridge installation had to be coordinated around cars and trains as a congested and complex site. The solution was to fabricate complete modules offsite for erection in short shut.
- Provisions were made for connecting to existing services, where the specifics and quantities were yet to be determined.
- The main span was transported on a jinker trailer system from Hamilton to the site and lifted directly onto the towers.
- One Bridge Tower was fixed and the other tower was on sliding bearing to allow movement. Existing Pipes were buried and so restrained while the temporary pipes could move with the TSB. This was solved by fixing a double knuckle joint which allowed pipe movement in all directions.
- NZS 5131 had just come into effect and required some work with consultants on the interpretation of QA requirements in particular welding details.
