Physical model test of seismic dynamic response to accumulative landslide

The accumulative landslide of Yushu Airport Road, induced by the Yushu M7.1 earthquake, has a slope of about 10 degrees and the size is 317 m x 482 m x 19.8 m in length, width and thickness direction. It is composed of three layers, i.e. an overlying layer consisted of gravel soil, a sliding zone consisted of pebble soil and a bedrock layer. In this paper, the large-scale shaking table model test is carried out to study the slope's capacity to withstand the vibration load after the earthquake and the contribution of the vertical component of the earthquake to the stability of the slope, and its dynamic response characteristics and failure mechanism are also analyzed. The results show that the permanent deformation of accumulative formation's landslide under strong earthquake is an important factor causing seismic geological hazards. With the increase of seismic intensity, the foot of slope firstly breaks down and settles. The arched fissures develop in the middle of the slope and the subsidence occurs. Furthermore, a series of tensile cracks and shear fractures occur at the top of the landslide and they advance towards the waist of the slope, showing typical tractive landslides. Peak ground acceleration(PGA), dynamic soil pressure and acceleration spectrum are positively correlated with the intensity of the input seismic wave and the landslide elevation. The PGA amplification coefficient exhibits distinct nonlinear characteristics, and its variation trend decreases with the increase of seismic load intensity. The vertical component of seismic wave has a slightly greater influence on the PGA amplification coefficient of landslide than the horizontal component.