Process–property modeling and the forming mechanism of preloading–vibration-coupled rock-like materials

Rock-like analogue materials are essential for reliable underground engineering physical modelling, and preloading-vibration compaction provides an effective way to optimize the performance of fluid-solid coupled similar materials. However, the quantitative correlations of material properties with preloading force, excitation frequency and vibration duration remain unclear. This paper establishes a process-property theoretical framework for similar material design based on compaction parameters. By developing regression models of physicomechanical parameters and a void-ratio-based semi-theoretical model, the evolution characteristics of density, compressive strength, elastic modulus, tensile strength and water absorption are quantitatively characterized, realizing the correlation between forming parameters and macroscopic mechanical performance. The results indicate that excitation frequency dominates all physicomechanical properties. The observed sensitivity patterns are consistent with a structural stability-oriented mode (f > t > P) that may be associated with sufficient particle rearrangement, whereas compressive strength and water absorption conform to a limit-bearing and porosity-oriented mode (f > P > t), in which preloading force is inferred to enhance material skeleton stiffness by improving particle interlocking. The calibrated model predicts a recommended frequency window of approximately 20-21 Hz within the investigated range, which favors the simultaneous acquisition of high density, high tensile strength and low water absorption. The research findings are successfully applied to a large-scale 3D rock mass similarity reconstruction system based on vibration compaction, demonstrating that process-controlled fabrication promotes the automation and reproducibility of physical modelling.