McDowall Affleck assisted York-Rizzani De Eccher Joint Venture during the construction of the Matagarup Bridge. In the construction of a large span bridge the temporary works and the erection process are critical design aspects and often the key factors for the success of the project. Rizzani De Eccher are world leaders in the construction of large span bridges and together with their subcontractor, ALE, have designed a very efficient erection system which has allowed a quick erection of the main arch of the bridge. McDowall Affleck were appointed for the detailed design of the two spreader beams which were used to lift in place the two wishbones now connected to form the main arch of the Matagarup Bridge.
McDowall Affleck completed the detailed designs of the main arches lifting beams, shear keys on main arches and the lifting beams lowering system.
The challenges we faced were complex spatial geometry not allowing direct connection of lifting beams to bottom chords, no bolted connection allowed to wishbones, balancing complexity vs accuracy of the issues and the loads test weren’t possible due to the magnitude of the loads.
We overcame these issues by introducing skewed connecting arms to form a portal frame, clamped connections and shear keys adopted. We used linear static analysis using a Solidworks 3D model with static load conditions at critical steps of lifting. Which was validated by an independent verifier.
Lifting beams were a key element for the success of the erection process. Hiring of lifting towers was extremely expensive, McDowall Affleck’s designed lifting beams performed as expected minimising the erection time.