The multiple earthquakes induced progressive failure of the Xinmo landslide, China: based on shaking table tests

Maoxian Country in Sichuan Province, China is a quake-prone mountainous area. Within 300 km of it, there have been more than ten strong earthquakes higher than Ms6.0 on record. The nearest one is the Diexi Earthquake of 1933, 8.7 km from Maoxian County. A catastrophic scale landslide, the Xinmo landslide, took place on the steep cataclinal slope of Xinmo Village on June 24, 2017. Shear failure happened to the phyllite layer of rich fissures during the landslide. In this paper, shaking table tests have been conducted on the Xinmo landslide as a prototype, and a non-contact deformation measurement based on the digital image correlation (DIC) technique has been made to analyze the dynamic response and deformation of the slope under accumulated seismic actions. As the results, stress amplification is found at the end of joints on the potential slide face. Failure starting from the middle of the potential slide face in the beginning extends upwards and downwards along the face, and leads to a steep tension crack on the top of the slope and a buckling failure of radial-arc cracks at the foot. A semi-steep radial crack in buckling part has a shear failure. The tensile stress amplification on the discontinuous face contributes to the failure accumulation of it and asymptotic failure of the slope. It proposed that the closure and downward displacement of tensile crack on the top of slope, buckling phenomenon at the foot of slope and shear failure of semi-steep crack are all the bad omens of landsliding.