The Charles Grimes Bridge crosses the Yarra River in Melbourne's central business district. The project required the demolition of the existing twin bridge structures, to be replaced by two new bridges with complex horizontal and vertical geometry. Realignment was required as part of the changed traffic network in and around Melbourne Docklands.

The bridge superstructure consists of five 110' main spans over the river, utilizing 67" deep, pre-stressed super-T beams. The approach structures comprise 5 smaller spans, between 39' and 79' in length, over the existing wharf and riverbank. Each of the bridges carries four traffic lanes and a footpath.

SAM was used on the Charles Grimes Bridge project as the main design tool for the bridge superstructure. Due to the complex geometry and layout, it was necessary to model and design each of the bridge beams individually. In the SAM grillage models, the pertinent beam data such as overall section dimensions, beam length, tendon layout and so on were defined and assigned to each grillage beam graphically. The section properties required for analysis were calculated automatically. SAM's influence method for obtaining critical vehicles positions enabled rapid preparation of design load effects for each beam. Using the integrated analysis and design method, the critical load effects for each beam was checked against member capacities. The main advantage of this process was the speed at which changes to any of the bridge parameters such as section or beam data could be made, in order to obtain revised critical load effects for design. At each design iteration, SAM produced detailed graphical and hand calculation style output for verification purposes.

Ove Arup & Partners senior structural engineer Andy Duncan said: "The use of SAM undoubtedly assisted in speeding up the analysis and design, of the various combination of span types and beam configurations, that resulted from the complex curved geometry."