Damage Evolution of Rock Slopes Under Seismic Motions Using Shaking Table Test

Seismic landslides cause heavy casualties and economic losses as well as severe damage to the geo-environment. In areas with frequent earthquakes, each seismic event could induce the occurrence of damage. The damage evolution in rock slopes is the key factor to trigger collapse or landslide. To investigate the damage evolution of rock slopes under seismic motions with different amplitudes and directions, a slope model scaled from the Huaping bank slope in Yunnan Province, China, was constructed and a large-scale shaking table test was conducted. The results show that the acceleration amplification coefficient (M_PGA) decreases with the increase in input seismic motion amplitude, indicating that shear strain increases and shear modulus decreases in the slope owing to the damage accumulation. Based on the dynamic deformation response of the slope, the damage degree defined as the ratio of permanent displacement to peak ground displacement is proposed to quantitatively identify the damage evolution of the slope, and it is verified by the phenomenon of crack development process. The analysis of damage degree reveals that the damage evolution within the rock slope is primarily controlled by the horizontal seismic motion, and significantly developed in the area between slope shoulder and slope bottom. When the input horizontal motion is 4.46 m/s², the slope model fails and the damage degree reaches the maximum over 60%. The meaning of damage degree could offer a better comprehension for the damage development process in rock slopes under seismic motions.