关键词: 灰岩, 滚动摩擦试验, 摩擦特性, 摩擦碎裂机制

Abstract: Frictional characteristics of sliding planes are the critical issues in the kinetics of high-speed rockslides. The friction experiments of dry and wet limestone samples at different pressures and rolling velocities are conducted to investigate dynamic frictional characteristics (i.e., friction coefficient and wear rate) using the rolling wear test equipment. Experimental results show that for dry limestone, there is a negative correlation between the rolling friction coefficient and the rolling velocity, but it is a positive relationship for wet limestone. Whether the specimen is dry or wet, there is no apparent relationship between the rolling friction coefficient and the normal pressure. For dry limestone, the wear rate of rolling specimen (i.e., as sliding mass) and static specimen (i.e., as sliding bed) is positively and negatively correlated with the rolling velocity, respectively. However, for wet limestone, the wear rate is positively relevant to the rolling velocity. In addition, based on the Hertz Elastic Contact Theory, we deducted the maximum compressive and tensile stresses of the friction spot, and then proposed the friction-fragmentation mechanism of brittle limestone under corresponding conditions. This study can provide the design parameters for the disaster prevention of the high-speed limestone rockslides.

Key words: limestone, rolling friction experiment, frictional characteristics, friction-fragmentation mechanism