DFI - PFSF Piling & Ground Improvement Conference 2022 Proceedings, (DFI and PFSF)
Existing Pile Length Assessment Using Geophysical and Low Strain Testing Methods
Bruce J. McPherson and Jeremy H. Hill
With substantial increases in city land values over the last 10 years in Australia there has been a lot of projects involving the upgrade of existing buildings or new basement construction directly adjacent to buildings supported on pile foundations. In both cases it is necessary to establish existing pile lengths where no as-built pile construction records are available. Low-strain pile testing methods are generally the most inexpensive way to determine the length of existing piles. Where access to the pile head or upper pile shaft is not available, downhole geophysical methods have been used to successfully determine the length of existing foundation and shoring piles along the boundary of properties where new basement construction could undermine the existing piles. The interpreted pile dimensions are coupled with a ground model to assess the impacts of the proposed excavation on the stability, bearing capacity and potential settlement of the existing pile or shoring system. In the case of building upgrade projects, these details are used to assess whether existing piles are adequate to cater for load increases associated with the redevelopment and, if appropriate, for increased seismic design requirements.
|article #3844; publication #1076 (IC-2021)|