Embodied carbon optimisation of concrete pile foundations and comparison of the performance of different pile geometries

Concrete production and construction are responsible for a considerable share of the total carbon emissions annually. With the emerging need to cut carbon emissions from the construction sector, there has been a big interest in optimising the embodied carbon of superstructures. However, limited attention is given to optimising the embodied carbon of foundations as most designers are more interested in addressing the optimal foundations cost instead. For the first time in the open literature, this paper presents a generic genetic-algorithm-based tool to optimise the design of reinforced concrete piles. The algorithm is capable of allocating the optimal design parameters and geometry for reinforced concrete piles at any given soil conditions and required pile capacities. The algorithm is used to compare the environmental impact of different concrete pile types; solid cylindrical piles, hollow cylindrical piles, solid tapered piles and hollow tapered piles at different load capacities, the optimisation results are then compared to common industrial pile designs to quantify the possible carbon and material savings. Results show that a significant cut of more than 70% of the embodied carbon values can be achieved if the optimal pile type is used compared to common industrial design. Moreover, a finite element model built and validated over ABAQUS is used to compare the geotechnical performance of the different pile geometries. Finite element analysis results show a negligible difference between the stiffness of the different pile types when tested in the same soil conditions highlighting an outstanding optimisation efficiency of the proposed optimisation tool.