Investigation on internal evolution process of slope under seismic loading: insights from a transparent soil test and shaking table test

Earthquakes are a primary factor in triggering slope instability and pose a serious threat to transportation. However, current research on the internal deformation of slopes under seismic loading remains limited. To investigate the effects of different seismic loadings on the evolution process and failure mode of slopes, a novel experiment combining transparent soil materials and shaking table tests was proposed in this study. Using a self-designed shaking table system, sine waves with amplitudes of 0.10 g, 0.15 g, and 0.20 g and frequencies of 3 Hz, 5 Hz, and 8 Hz were applied. Based on Particle Image Velocimetry (PIV) technology and non-intrusive monitoring techniques, displacement and velocity contour maps, whole-field average displacement and failure mechanism of the slope were analyzed. The results show that, as the vibration persists, the slope transitions from initial shallow linear sliding to overall circular arc sliding, exhibiting an obvious progressive traction failure mode. The evolution process of the slope could be divided into three phases: shallow low-speed sliding phase, overall rapid sliding phase, and overall low-speed sliding phase. Furthermore, the amplitude of seismic loading has a greater influence on slope deformation compared to its frequency. This novel experiment offers important insights into the internal evolution process of slopes under seismic loading.