Axial and lateral performance of spun-cast ductile iron helical tapered piles in clay

Abstract

A novel piling system is proposed to support solar energy panels: a spun-cast ductile iron (SCDI) tapered pile fitted with a single helical plate installed by mechanical torque. The proposed pile combines the efficiency of the tapered cross-section and the construction advantages of helical piles, as well as the competitive cost, effectiveness and durability of SCDI with a rough surface. This paper presents an investigation of its compressive, uplift and lateral performance in clay employing three-dimensional non-linear finite-element models. In addition, simulations of other pile shapes, including tapered and straight shafts, as well as conventional steel helical piles, were performed for comparison purposes. Effects of the pile length, installation technique and the presence of a top crust on the pile performance were investigated. The results demonstrated the feasibility of the proposed pile, especially for applications that impose high uplift and lateral loading. Moment–horizontal force interaction diagrams are provided to aid in design of the proposed pile when subjected to a combination of moment and horizontal loads.