Centrifuge tests on the load-bearing behaviour of prefabricated concrete screw-type piles

Due to very low noise emission during installation, prefabricated concrete screw-type piles (PCSP) could potentially be viable options as foundations for offshore and onshore structures. However, little attention has been paid to the axial load-bearing behaviour in compression of this specific prefabricated screw-type pile system in comparison with conventional displacement pile systems. This article describes an experimental campaign of centrifuge tests performed at 100g on both screw-type piles and straight shafted piles (SP) with diameters of 550 and 475 mm at prototype scale. The outer screw diameter (Ds) to pile core diameter (D) ratio amounted to Ds/D = 1.25, and the screw pitch (Lp) to pile core diameter (D) ratio (pitch ratio) was selected as Lp/D = 0.57. Saturated Vingerling Clay was used to model the soil layer, and a low loading rate was selected to simulate drained conditions. Piles were installed at 1g; therefore, the pile installation process was not fully modelled. For both pile diameters investigated, the results indicate an approximately 45% higher bearing capacity with the PCSP compared with the capacity of the SP.