The Tullamarine Calder Interchange project in Melbourne involved reconstructing a dangerous freeway intersection by adding a new exit ramp under existing bridges. To do this, the abutments of the bridges had to be partially demolished and rebuilt. The construction used a mix of techniques like soil nailing, ground anchoring, piling, underpinning, and reinforced earth to create more space under the bridges. The project successfully managed to widen the road beneath the bridges by about 10 meters while keeping traffic flowing. The innovative alliance delivery model allowed for flexibility and creativity in the design and construction process.