Hybrid Energy Piles as a Smart and Sustainable Foundation

Abstract

The disused factories’ areas represent a considerable part of the industrial archaeology of the city of Naples. In the last decades of the previous century, many of these factories were disused because of the ban on asbestos production by Italian law 257/1992. Of course, this was not the only problem that concurred to create a large number of disused industrial areas. Often the simple delocalization of manufactories in other countries contributed to this problem. The reuse of these areas requires polluted and contaminated land reclamation. The simple removal of the shallow soil layers is a widely used reclamation procedure. Furthermore, drilling operations either for piling or for tunneling may incur the same type of problem, taking into account that this movement can be very expensive depending on the total volume of soil to be removed and to be taken to disposal. In this study, a hybrid pile type is proposed as an environmentally friendly and cheap solution. Hybrid piles are installed by a combination of pushing and augering techniques. This installation method allows avoiding the removal and subsequent disposal of shallow contaminated soil. The mechanical behaviour of three hybrid piles equipped with strain gauges along the shaft is investigated via three loading tests. In the framework of the design of a new mall in a disused industrial area, the opportunity to provide a fully sustainable foundation solution by equipping the piles with heat exchanger pipes is also being investigated. Numerical simulations of the energy hybrid pile behaviour are presented, outlining further benefits of the new hybrid installation technique and comparing two different configurations of the heat exchanger pipes.