Experimental Study on Dynamic Response of the Large Shaking Table Foundation at National Facility for Earthquake Engineering Simulation (NFEES)

The large shaking table at Tianjin University's National Facility for Earthquake Engineering Simulation (NFEES) is the largest in the world, featuring a rigid‐flexible foundation differing from the conventional rigid block type. This design meets the structural requirements for large‐scale shaking tables and is suitable for sites without ideal soil conditions. However, the vibration response characteristics and spatial distribution patterns of this foundation under dynamic loading remain insufficiently studied. This paper presents a test investigation into this newly developed foundation's response, employing white noise sweep and sinusoidal excitation tests to obtain actual acceleration response data and its spatial distribution. Furthermore, the key factors influencing the acceleration response distribution are analyzed by considering both the structural properties and the excitation characteristics. The results show that at excitation frequencies below 15 Hz, the foundation exhibits good overall integrity. In contrast, high‐frequency horizontal excitations tend to localize the response in the excitation region, while high‐frequency vertical excitations amplify the response in the flexible area, leading to a clear deviation from rigid‐body motion. This study provides a reliable and authentic data source for future theoretical and numerical research, and the findings offer valuable engineering insights and practical guidance for the design and application of similar large‐scale shaking table foundations.