Environmental and Economic Optimization of a Conventional Concrete Building Foundation: Selecting the Best of 28 Alternatives by Applying the Pareto Front

This research optimizes the environmental impact of a conventional building foundation in Northern Europe while considering the economic cost. The foundation is composed of piles and ground beams. Calculations are performed following relevant building Eurocodes and using life cycle assessment methodology. Concrete and steel accounted for the majority of the environmental impact of foundation alternatives; in particular, steel on piles has a significant influence. Selecting small sections of precast piles or low-reinforcement vibro-piles instead of continuous-flight auger piles can reduce the environmental impacts and economic costs of a foundation by 55% and 40%, respectively. However, using precast beams rather than building them on site can increase the global warming potential (GWP) by up to 10%. Increasing the concrete strength in vibro-piles can reduce the eco-costs, ReCiPe indicator, and cumulated energy demand (CED) by up to 30%; the GWP by 25%; and the economic costs by up to 15%. Designing three piles instead of four piles per beam reduces the eco-costs and ReCiPe by 20-30%, the GWP by 15-20%, the CED by 15-25%, and the costs by 12%. A Pareto analysis was used to select the best foundation alternatives in terms of the combination of costs and eco-burdens, which are those with vibro-piles with higher concrete strengths (low reinforcement), cast in situ or prefabricated beams and four piles per beam.