The BORR-Bussell Highway bridge sits at the southern end of the BORR alignment forms part of an innovatively designed interchange in the shape of a Y.

Due to this configuration, the interchange design had to meet some unique requirements to accommodate the curve of the BORR alignment. So, an equally unique bridge beam design had to be incorporated.

The bridge is on a high skew of 41.5 degrees – meaning that the angle between the bridge structure itself, and the road below, is not perpendicular. This ensures a smoother and more continuous transition on and off the bridge for vehicles without the need for sharp turns.

To achieve this design, a project-first continuous beam design needed to be used with specific construction considerations taken into account.

The Construction: Beam Installation

One side of each beam was installed on the abutments (i.e., the ends of the bridge span) and the other side supported by temporary structures. Then a stitch pour took place to connect the various precast concrete segments of the bridge and lock each beam to the span next to it. When completed, the beams will have the permanent support they need, and the temporary support structures can be removed.

To achieve this for all eight beams, an LTM1750 crane—which is a 750-ton mobile telescopic crane for extra strength and reach—was used. It took five days for the beam installation to be completed but now that it has, the BORR-Bussell Highway bridge is ready for the next stage in its construction: deck formwork and concrete pour!