Mesoscopic Numerical Simulation Method for Determining the Wet-Screening Effect in the Evaluation of Dam Concrete

The research and prediction of the mechanical properties of dam concrete constitute a difficult task due to the wet-screening effect. Mesoscopic numerical simulation is one of the most efficient methods to analyze the physical relationship of strength characteristics between dam concrete and wet-screened concrete. The meso-parameters of numerical simulation determine the accuracy of the simulation, and the trial-and-error method is commonly used. However, using the trial-and-error method to determine mesoscopic parameters makes it accidental for numerical simulation results to match experimental data. To address this issue, a response surface function form is established for the parameter inversion of the mesoscopic constitutive model of dam concrete. A bridge is established between macroscopic experimental data and mesoscopic parameters to determine the optimal combination of mesoscopic parameters. By considering the effects of wet-screen strength results, specimen size, and random location of aggregates, the optimal mesoparameters were substituted into the model, and the model loading results were compared with the test results. The results show that the numerical simulation results are consistent with the experimental results. The dispersion of the results in the mesonumerical method is within the 0.9%–2% range due to the location and shape of aggregates, as well as the stress–strain curve used for calibration. This method can be used for accurate analysis of mesonumerical simulation of dam concrete.