Rapid and long runout landslides as a special landslide hazard, display high mobility, long runout travel distance and wide damage area, and bring great loss to human life and property, of which dynamic mechanisms have attracted demand attentions of the researchers all over the world. Liquefaction mechanism of landslides was proposed to explain that the formation of excess pore water pressure and the reduction of effective stress lead to the decrease of the friction coefficient of the base and the landslide long runout movement. In this paper, we reviewed the factors affecting the liquefaction intensity and the liquefaction mechanism of the landslides on the basis of previous research, and the mechanisms of the liquefied landslides were generally summarized into two types: structural liquefaction and sliding zone liquefaction. Based on remote sensing interpretation and field investigation, the preliminary research of the formation mechanisms of two typical liquefied rapid-long-runout landslides named Yushu landslide and Luanshibao landslide in Tibetan Plateau were conducted. Results showed that Yushu and Luanshibao landslides were different in triggering mechanism, movement and accumulation geomorphologic unit, and liquefaction mechanism. Yushu landslide was a collapsed deposit landslide occurring in a mountain valley with a small volume but a long runout distance triggered by heavy rainfall. The sliding zone soil was saturated loose sandy clay (fine grain) accumulated in the gully before landsliding, the particle breakage of which during shearing could be negligible. The liquefaction was mainly induced by destroying the soil structure under undrained loading. Luanshibao landslide was a granite landslide occurring in the piedmont basin triggered by oblique-thrusting during an ancient earthquake, the sliding zone soil of which was saturated loose weathered granite sand having crushability. The sliding zone liquefaction induced by grain crushing was the main reason resulting in its rapid and long runout movement.
