Performance of battered mini driven pile group in basaltic clays: field testing and numerical modelling

A new battered mini driven pile group footing system developed recently in Victoria, Australia shows considerable advantages compared to traditional reinforced concrete footings. It can be manually handled and installed with light jackhammers without the need for an excavation or drilling. Soil disturbance is also much lower than other types of foundation systems and being concrete-free system leads to a shorter construction time and lower cost and carbon footprint. This new system is known as Surefoot. One of the best methods to ascertain the performance of foundation systems is field load testing. To evaluate the ultimate capacity of this system, eight static compression and pull-out tests were performed. The results were discussed according to commonly used interpretation methods and 3D numerical modelling. These tests were all conducted in an area of quaternary basaltic clay deposits in Braybrook, Victoria. This paper presents results of the soil investigation in terms of in-situ and laboratory tests, field static load tests and evaluation of the current design method. The field test and numerical modelling results suggests that the new battered mini driven pile system is a time and cost effective alternative to traditional footing systems.