Optimizing open-end piles is crucial for sustainability as it minimizes material consumption and reduces environmental impact. By improving construction efficiency, less steel is needed, reducing the carbon footprint associated with production and transportation. Improved pile performance also results in more durable structures that require less frequent replacement and maintenance, which in turn saves resources and energy. This paper presents a parametric study on optimal designs for open-ended piles in sand, presenting a novel approach to directly compute optimal pile designs using CPT results. It addresses challenges posed by soil variability and layered conditions, with the optimization model accounting for interdependencies among pile length, diameter, wall thickness and soil properties, including the pile–soil plug system. A mixed-integer optimization model OPEN-Pile was developed, consisting of an objective function for pile mass and CO2 emissions. The objective function was constrained by a set of design and geotechnical conditions that corresponded to current codes of practice and recommendations. The efficiency of the developed optimization model is illustrated by two case studies. In the case of Blessington sand, the calculation results show that it is more economical and environmentally friendly to increase the pile diameter and pile wall thickness than the pile length. In efficient design, the ratio between diameter and wall thickness is calculated at the upper limit. For the optimum design of piles in Blessington sand, the optimum ratios of pile length to diameter, diameter to wall thickness and length to wall thickness are 5, 50 and 250, respectively. In a layered soil profile, the decision of where to place the pile base depends on the resistance of the cone tip and the thickness of the individual layers. To determine in which layer the pile base should be placed, we need to perform an optimization for the given design data.
