This study presents an optimal performance model for predicting the bearing capacity of concrete piles in alluvial soils by comparing Artificial Neural Network (ANN) models optimized with Particle Swarm Optimization (PSO), Harris Hawks Optimization (HHO), Grey Wolf Optimization (GWO), Genetic Algorithm (GA), and Artificial Bee Colony (ABC). A database of 194 data points was collected from the literature and preprocessed. Multicollinearity and cosine amplitude sensitivity analyses were then performed. Of the dataset, 164 data points were used for training and 30 for testing. Performance evaluation showed that the ABC_ANN model achieved over 95% accuracy in both phases. Further validation through Taylor plots, scores (35 for both training and testing), regression error characteristic curves (areas = 0.1982 for training and 0.1078 for testing), generalizability ranking (first), and uncertainty analyses confirmed the superior predictive capability of the ABC_ANN model. Curve-fitting analysis indicated a slight overfitting (1.97) for the ABC_ANN model, followed by the HHO_ANN model. This overfitting was mainly attributed to multicollinearity in features such as soil layer depth, ground elevation, pile tip elevation, and the standard penetration blow count at the pile shaft (a highly sensitive feature, sensitivity = 0.98). Nevertheless, discrete accuracy metrics consistently verified the robustness of the ABC_ANN model in predicting pile bearing capacity. Therefore, this study identifies the ABC_ANN model as an optimal tool to support geotechnical engineers and designers in estimating the bearing capacity of concrete piles.



