Nepean and LansvaleBridge survey–Ventia

Our client, Ventia, engaged Road & Civil Surveys to capture and model the Nepean and Lansvale bridges as part of upgrading the significant features of the existing bridges. Due tothe age of both bridges, the differential shrinkage along thebridge has reached apoint where the steel roller bearings are approaching their maximum extension acrossthe bearing plates.

To maintain and replace the bearings and plates, it was imperative to have an accurate 3D model of both bridges, including each roller bearing and respective bearing plates.

Access from the top of the bridge was minimal, which alleviated the need for any road closures and traffic disruptions.

In consultation with Ventiaand AECOM (the consulting engineering company that designed enhancements for the bridge), Geotwin recommended laser scanning as the most efficient and accurate solution.

Road & Civil Surveys opted to use its Leica P40 high-definition laser scanner, the Leica RTC 360 Laser Scanner, and the Reigl vz600i,  combined with high-accurate Survey Control, to provide best-in-class capture for speed and accuracy. This enabled the creation of an accurate 3D model for the bridge, with high detail of each roller bearing and plate.

In planning the project, Road & Civil  Surveys team decided to scan the bridges from multiple angles and areas. Each scanning Station used multiple scanning targets shot with 1”total stations to ensurethat all scans could be consolidated into a single model.

It took more than 100 scanning stations to capture both bridges without disrupting livetraffic or requiring pedestrian management.

The survey team utilised our highly accurate and highly dense scanners to create adata-rich Point cloud.

Using a high-definition scanner instead of traditional survey methods enabled the survey to be completed over two days, resulting in an accurate and comprehensive 3D model