Our involvement
- Geotechnical site investigation including boreholes, CPTs and DMTs
- 3D numerical analysis to model the interaction between the soil and the piled raft slab.
- Static load testing
Project challenges
- Characterisation of the highly variable subsurface profile across the site.
- Limited strength of some of the soil strata.
- Presence of uplift forces on completion of construction and termination of dewatering.
- Complex interaction between slab, soil and screw piles.
Our solutions
We proposed and designed a piled raft foundation supported by more than 200 multi-turn single helix screw piles to reduce total and differential settlements to acceptable magnitudes and resist uplift forces on completion of construction and cessation of dewatering. PLAXIS 3D program was used to carry out the numerical analysis. The predicted performance of the piled raft was calibrated and optimised using the results of static pile load tests. Monitoring of the settlement of the piled raft slab was completed and compared with the predicted results.
Published Paper
Parsa-Pajouh, A.; Theunissen. W.; Smith, N.; and Speechley (2022). Soil-foundation Interaction analysis of a piled raft system supported by single helix screw Piles. In Proc. 20th International Conference on Soil Mechanics and Geotechnical Engineering (Sydney). Australian Geomechanics Society, Sydney, Australia.
