Prediction of uplift and compression bearing capacity of screw piles in saturated sand: Prévision de la capacité de charge en compression et en soulèvement des pieux vissés dans le sable saturé

Accurate determination of bearing capacity for screw piles remains an unresolved challenge. Previous research has predominantly concentrated on uplift capacity equations for helical anchors, with limited focus on compression capacity. This study aims to assess and adapt existing methodologies for determining the bearing capacity of screw piles, accounting for the distinct geometrical features, and applying them to both uplift and compression capacities. Additionally, Cone Penetration Test (CPT)-based methods are investigated for their applicability in this context. The research methodology entails reviewing current bearing capacity determination methods, modifying them to accommodate the unique screw pile geometry, and analysing CPT-based approaches. Static load tests are conducted at Aalborg University's laboratory to obtain reference static bearing capacities. Comparisons are drawn between the outcomes of the adapted earth pressure theory-based and CPT-based methods and the lab-obtained static bearing capacities. The results indicate that the existing framework is inadequate and unreliable for determining the uplift and compression bearing capacity of the screw piles investigated. The study highlights the necessity for further research and development of novel methodologies to enhance the accuracy of screw pile bearing capacity predictions.