Prediction of undrained bearing capacity of strip footings above voids using hybrid machine learning models
摘要
The current research proposes a machine learning (ML)-based framework to predict the undrained bearing capacity of strip footings above voids and to investigate the influence of key governing parameters. A standalone Extreme Gradient Boosting (XGBoost) model is first developed as a baseline predictor. To further enhance its performance, XGBoost is hybridized with four metaheuristic optimization algorithms: Particle Swarm Optimization (PSO), Slime Mould Algorithm (SMA), Gannet Optimization Algorithm (GOA), and Beluga Whale Optimizer (BWO) for hyperparameter tuning, resulting in four hybrid models: XGBoost-PSO, XGBoost-SMA, XGBoost-GOA, and XGBoost-BWO. The dataset comprises 404 randomly generated samples obtained from finite element simulations conducted using Plaxis 2D (V20). Each sample includes seven input variables: void width (W/B), vertical distance (Y/B), horizontal distance (X/B), void height (H/B), load eccentricity (e/B), inclination angle (i), and undrained shear strength of soil (Cu), while the undrained bearing capacity (qu) is considered as the output variable. The dataset was divided into 80% for training and 20% for testing. Model performance was evaluated using eight statistical indicators: Mean Absolute Error (MAE), Scatter Index (SI), Relative Absolute Error (RAE), Root Relative Squared Error (RRSE), Standard Deviation Error (SDE), Theil Inequality Coefficient (TIC), Index of Agreement (IA), and the Coefficient of Determination (R2). Comparative analysis demonstrates that the XGBoost-SMA and XGBoost-PSO hybrid models achieve superior predictive accuracy, whereas the XGBoost-GOA and standalone XGBoost models show the poorest performance.