Research on the Optimization Design of Large-Diameter Silo Foundation Piles Based on an Automatic Grouping Genetic Algorithm

Pile foundations are extensively employed in large-diameter silos owing to their superior stability. However, conventional equal-stiffness designs often require thicker pile caps and higher reinforcement ratios, leading to increased construction costs. It promotes the study of this paper, which optimized the design of pile foundations for large-diameter silos to reduce construction costs. A three-dimensional (3D) finite element (FE) numerical model, incorporating superstructure–foundation–soil interaction, was developed using ANSYS to analyze the effects of pile cap thickness (PCT), pile length (PL), and pile diameter (PD) on maximum differential settlement (MDS). Sensitivity analysis quantified the influence of each parameter. Additionally, improvements to the automatic grouping genetic algorithm (AGGA) were proposed and implemented in Matlab to enhance design optimization. Results show that PCT has the greatest impact on MDS, followed by PL and PD. Optimal ranges are 1.7–2.3 m for PCT, 11.8–19.3 m for PL, and 0.6–1.2 m for PD. Using long-slender piles instead of short-thick piles reduces concrete consumption by 39.16% and decreases MDS by 73.5%, effectively mitigating secondary internal forces in the superstructure and pile cap. This approach enhances structural safety and overall system stability, offering a cost-effective solution for large-diameter silo foundations.