Repair Mulwala Bridge with Minimal Disruption
The bridge between the Victorian & NSW border towns of Yarrawonga and Mulwala spans a section of Lake Mulwala. The bridge opened in 1924 and is an integral part of how the two towns operate and exist on a daily basis. As the main means of crossing the Lake (and soon to be the only means of crossing between the two towns) the bridge is utilized by up to 9000 vehicles per day! So, when a truck happens to collide with one of the bridges vertical steel members midway across the bridge bringing into question the structural integrity, how can a repair be carried out in a timely fashion with the least possible disruption to the busy life of the bridge?
Using high accuracy 3D scanning systems, the current sizes and locations of all adjoining structural members were captured within a half day closure. In addition to the offending steel member, the Wysiwyg 3D Engineers also captured a large section of the surrounding features of the bridge for documentation. These additional features would also later tie in with the surveying co-ordinates for the existing road/footpath access on either side of the bridge.
With the bridge back open to business, the scan data was then processed by our Engineers and then 3D modelled. This 3D model was then used for the design of a new vertical steel member to directly replace the damaged one. In addition to the design process, the 3D Model was used for planning the installation process. This planning was critical in fast tracking the manufacturing process. It also allowed for the majority of the manufacturing to be carried out prior to arrival at the bridge site. The 3D Model played a critical role in condensing the installation process resulting in a bridge closure for only a number of days as opposed to several weeks.
No doubt the community on both sides of the bridge were grateful for the rather minor disruption in comparison to the alternative method.