Numerical modeling-based deformation prediction for tunnel portal talus slopes

To predict the deformation behavior of the talus slope under varying reservoir water levels and dynamic train loads during tunnel operation, this study investigates the talus slope at the Daqianshiling tunnel portal section. Initially, the excavation process of the tunnel portal section was simulated using numerical modeling, with simulation outcomes systematically compared to in situ monitoring data. Subsequently, the numerical model was iteratively calibrated to ensure overall concordance with field conditions. Upon calibration, the model was employed to simulate talus slope deformation under diverse water level and train load scenarios encountered during operation. The results indicate that deformation during the reservoir filling phase is markedly greater than that observed during the drawdown phase. Slope stability is substantially reduced when train loading coincides with elevated water levels. The methodological framework in provides a robust basis for the prediction of deformation in analogous engineering projects.