Bridges

The Manchester Road and Maroondah Highway (M&M) Level Crossing Removal Projects (LXRP) and Hallam South Road (HLM) LXRP involve the construction of new elevated rail viaducts comprising of a simply supported U-Trough superstructure on both 'up' and 'down' tracks and an elevated island and side platform.

The structures comprise of precast U-Trough girders and precast crossheads similar to those constructed on several previous level crossing removal projects. These elements are heavily reinforced and incorporate many cast-in elements such as service ducts, reinforcement ducts, ferrules, cast-in hold down bolts, etc. M&M and HLM projects involved construction during short rail occupations; thus, there was a need for well documented precast elements.

This paper describes the application by the South Eastern Program Alliance (SEPA) of 3D reinforcement modelling for the precast U-Troughs and the precast crossheads to simplify the fabrication process. Various modelling software packages were utilised. Software included ProConcrete, Tekla and Revit software to model the reinforcement and Solibri as a model reviewing tool by the Contractor, the Designer and the Precaster.

Modelling reinforcement in a 3D environment helps ensure reduced reinforcement congestion and elimination of clashes. Steel reinforcement in concrete elements can be viewed in detail in an accurate digital representation. The 3D model can also be used for planning the sequence of placing and tying the reinforcement and informs the bar shapes in some instances as well as the erection of the precast crossheads and U-Troughs.

Modelling enabled the reinforcement fabricator to extract the reinforcement quantities and produce the bending schedules by utilising the Issued for Construction 3D models. When alterations were required to the reinforcement, the alterations could be easily implemented.

The 3D modelling led to a significant reduction in the number of Requests for Information (RFIs), enabling a shorter fabrication and construction programme.