Abstract: In order to characterize the transportation mechanism of the high-speed rockslide, it is significant to investigate the tribological characteristics of the sliding surface. However, the investigation of tribological characteristics has not been thoroughly revealed. Taking the Wangshan-Zhuakousi rockslide in Emeishan city of Sichuan province as instance, the engineering geological conditions and the motion characteristics of the rockslide were obtained through field geological survey and video surveillance. Based on the high-speed friction experiments of the rockslide masses (basalt) and the sliding plane (tuff) by the pin and disc worn instrument, the tribological characteristics (dynamic friction coefficient and microscopic wear surface appearance) were analyzed under dry and saturated conditions. The results show that: the dynamic friction coefficient of the sliding plane (the interface between basalt and tuff) is much smaller than that of basalts. Regardless of the dry and saturated conditions, the dynamic friction coefficient of the sliding plane (the interface between basalt and tuff) is negatively correlated with both the frictional velocities and the normal pressures in the experiments. Regardless of the dry and saturated conditions, the dynamic friction coefficient of sliding mass (basalt) is also negatively correlated with the frictional velocities, whereas it is positively correlated with the normal pressure in the experiments. In the high-speed friction process, the dynamic friction coefficient is increased instantly due to the dilative shear failure of the sliding surface. The experimental results can be adopted for explaining the high-speed motion of the hard rockslides containing the weak interlayers. In addition, the findings in this study can provide essential design parameters for disaster prevention and high-speed rockslide mitigation in the tuff and basalt areas.

Key words: high-speed rockslide, tuff, basalt, high-speed friction experiment, frictional characteristics