Dynamic response of undisturbed loess slope based on dynamic centrifugal testing

Abstract

Loess slopes are prone to seismic subsidence deformation and sliding failure under seismic loads. In this paper, the dynamic centrifugal model test of the undisturbed loess slope with a geometric scale of 1: 20 is designed and completed for the typical Malan loess slope. By combining numerical simulation methods, the dynamic response and seismic subsidence failure characteristics of loess slopes under different influencing factors (excitation, moisture content, slope ratio) were analyzed. The results show that the dynamic amplification coefficient of the loess slope increases nonlinearly with the slope height, and the test results are consistent with the numerical simulation results. The crest of the loess slope undergoes significant seismic subsidence deformation, and the slope exhibits a sliding trend of lateral extrusion. Under the action of strong earthquake, the structural cracks of the undisturbed loess slope developed significantly, resulting in serious cracking damage. The seismic subsidence deformation and fracture development of loess slope are more obvious with the increase of initial moisture content. It can be seen that under the action of earthquakes, loess slopes undergo seismic subsidence, tension cracks, and structural cracks develop, forming seepage channel cracks and potential slip surfaces, providing conditions for slope sliding.