Mitigating infrastructure risks in gypseous soils: combining random forest modeling with monte carlo simulation
摘要
The construction of infrastructure on gypseous soils is challenging because gypsum dissolves upon wetting, creating additional voids and inducing settlement and collapse. This study proposes a hybrid framework that couples Monte Carlo simulation (MCS) with Random Forest (RF) regression to quantify and predict leaching strain, defined here as the vertical strain accumulated during continuous leaching under sustained load due to gypsum dissolution. Leaching tests were conducted using an Oedometer-Permeability Leaching Test (OPLT; 75 mm diameter, 19 mm height) and a Modified Permeability Leaching Test (MPLT; 150 mm diameter, 50 mm height) on remoulded silty clay-gypsum mixtures (20–60% gypsum by weight) compacted at dry unit weights of 14–16 kN/m3 and loaded to 200 kPa, followed by 24 h saturation and 7 days of leaching. The measured permeability, total dissolved solids (TDS), and leaching strain were used to parameterize a probabilistic model. MCS (100,000 samples) provided the distribution of leaching strain and associated reliability metrics (beta and Pf) for a failure threshold of Ls = 1%. An RF model trained on the generated dataset achieved high predictive accuracy (R approximately 0.96 on testing) with low RMSE/MAE; slight overfitting is attributed to limited experimental coverage and the use of synthetic data generation. The reliability analysis yielded beta = 0.19 and Pf = 0.43, indicating an unacceptably high failure likelihood under the analysed conditions and motivating mitigation measures (stabilisation, drainage, and conservative design).