Dynamic Performance of a Geosynthetic-Reinforced Soil Bridge Abutment in a Shaking Table Test

With the widespread application of geosynthetic reinforced soil (GRS) bridge abutment technology, the construction of GRS bridge abutments in seismically active areas has become commonplace. To assess the dynamic response of GRS bridge abutments to earthquakes, this study uses a half-scale GRS bridge abutment model, in which longitudinal vibrations with different peak ground accelerations (PGAs) are applied to obtain the acceleration, deformation, soil stress, and reinforcement strain. The natural frequency and damping ratio trends are obtained using spare time-domain identification. In addition, the Hilbert and marginal spectra of the signals are obtained based on the Hilbert–Huang transform, and the damage evolution state is analyzed from both the time-frequency domain and energy perspectives. The results show that damage occurs at the top of the GRS abutment under dynamic conditions, the overall natural frequency of the abutment decreases, and the damping ratio increases. When the input motion PGAs were ≤0.4g, the abutment displacement and soil stress recover after the vibration, indicating that the bridge abutment performs well in this strength range. The amplitude of the Hilbert spectrum is positively correlated with the PGA amplitude of the input seismic wave, and no significant change is observed under smaller PGA conditions. By analyzing the trend of the amplitude of the marginal spectra of the different layers with the peak PGA value, the top of the bridge abutment is damaged, which verifies the spare time-domain identification results. This study provides a novel approach for the seismic damage identification and design optimization of GRS bridge abutments.