A Multi-Actuator Dynamics Platform for Reproducing Actual Three-Dimensional Wave Propagation in Transport Infrastructure

To address the complex wave propagation and soil-structure interaction mechanisms induced by increased traffic loads in modern highways, this study develops a novel multi-actuator dynamics platform for experimental simulation of three-dimensional dynamic responses in subgrade. The design principles and structural components of the platform are detailed based on the three-dimensional dynamic response of soil elements under moving vehicular loads. The platform innovatively integrates a fully digital servo control system with a synchronized seven-actuator linkage mechanism, enabling high-fidelity reproduction of moving vehicular loads and resultant principal stress axis rotation in soil elements. A physical model measuring [Formula: see text] ([Formula: see text]) was constructed in the laboratory, following actual engineering standards. Validation through in-situ measurements demonstrates that the platform accurately replicates key dynamic phenomena: actual three-dimensional stress wave propagation across subgrade soil, and principal stress axis rotation of subgrade soil element under cyclic traffic loading. This work establishes a pioneering methodology for analyzing transport infrastructure stability mechanisms, providing critical insights into long-term performance prediction of complex systems subject to stochastic dynamic loads.