Experimental investigation on the seismically induced cumulative damage and progressive deformation of the 2017 Xinmo landslide in China

A catastrophic landslide occurred in Xinmo village, Maoxian County, China, on June 24, 2016. The landslide destroyed the whole village and caused 10 deaths, and 73 people were reported to be missing. In this study, the contributions of historical earthquakes to rock damage and progressive deformation are the main focus. A detailed field investigation revealed that historical earthquakes seriously damaged the rock mass in the source area, and there were five macrocracks in this area before the landslide. The landslide was initiated along the cracks and foliation plane of the phyllite under long-term gravity. The rock damage induced by historical earthquakes was tested by uniaxial cyclic loading tests. The results indicate that the damage in the phyllite induced by earthquakes is significantly greater than that to slate and metamorphic sandstone. Moreover, the static loading after earthquakes can trigger the long-term deformation of phyllite, and it is accelerated with the incremental damage in the phyllite. Finally, catastrophic failure was triggered when the phyllite was in a significantly damaged state. As a result, the joint influence of historical earthquakes and long-term gravity loading contributed to the progressive deformation of the Xinmo landslide.