Ensemble Machine Learning Models for Estimating Stone Column Load-Bearing Capacity Using Combined Experimental and Field Test Data
摘要
This study is on the application of ensemble machine learning techniques in stone column bearing capacity prediction, integrating experimental and field test data across various soil conditions to address the limitations of traditional methods. This paper developed and evaluated several predictive models, including linear regression, gradient boosting, support vector regression, K-nearest neighbors, and a newly proposed ensemble model. The results revealed that traditional linear regression produced moderate accuracy (R2 = 0.848, RMSE = 19,220.12, MAE = 14,449.63), while support vector regression substantially underperformed (R2 = 0.169, RMSE = 53,378.71, MAE = 20497.13), underscoring the challenges posed by data heterogeneity and nonlinearity. In contrast, ensemble approaches, exemplified by gradient boosting (R2 = 0.986, RMSE = 5806.08, MAE = 1697.49) and K-nearest neighbors (R2 = 0.987, RMSE = 5593.26, MAE = 1668.71), demonstrated remarkable improvements in accuracy. K-nearest neighbors emerged as the clear front-runner among the models tested, achieving the highest explained variance alongside the lowest error metrics. Its predictions were exceptionally stable; over 90% of residuals fell within ± 10% of actual capacities across all load ranges, and both training and validation R2 converged above 0.98 as the dataset expanded, indicating minimal overfitting. This combination of peak accuracy, consistency under diverse soil conditions, and strong generalization made K-nearest neighbors the preferred choice for rapid, reliable estimation of stone-column bearing capacity in practical geotechnical design.