Pile load tests using Osterberg cell for New Bridgewater Bridge deep foundation

The New Bridgewater Bridge project is the largest transport infrastructure project in Tasmania’s history, which involves the construction of a new bridge over the River Derwent, and other associated road infrastructures. As part of the project requirements, a minimum of three sacrificial test piles with a minimum diameter of 1500 mm (concrete outer diameter) at representative locations were designed and constructed to verify the new River Derwent Bridge pile foundation design using Osterberg cell (O-Cell) test method. This paper discusses the basis of design, geotechnical issues, and challenges encountered in design and construction of test piles; then reviews testing performance and presents the interpretation of test data; and some interesting engineering recommendations and conclusions that have been used to expedite the approval for the installation of production piles. With this paper, the authors wish to provide some meaningful technical insights for future design and construction of similar deep foundations.