Anomalously Low Friction Whipping Effect of Sandstone Blocks Based on FLAC-3D

Abstract

With the continual increase of mining depths, the mechanical behaviors of deep rock masses present new forms and new characteristics. The whipping effect widely used in the construction industry is very similar to the partial dynamic responses of deep rock masses. Based on the structural characteristics, with the sandstone blocks as the research object, and the horizontal displacement and acceleration of the working block (horizontally impacted block) as the reference indicators, by experiments and through FLAC-3D numerical simulations, the influential mechanisms of the working block positions and sizes on the ultralow friction whipping effects were investigated. The work shows that, the intensity of the system’s ultralow friction whipping effect is closely related to the size of the working block. In the simulation, when the side length of the working block is 2/5 of that of the standard block (with a cube side length of 100 mm), the system structure will induce particularly severe ultralow friction whipping effects; within a certain range, the farther the working block position is from the disturbance source, the greater the intensity of the ultralow friction whipping effect will be. Beyond this range, a decreasing trend will occur, that is, the ultralow friction whipping effect intensity will increase first and then decrease with the distance between the working block and the source block.