Tribological properties of granular filled rock joints

A campaign of systematic testing of granular filled rock joints was conducted to determine the effect of joint fill characteristics, such as grain size, infill thickness joint wall type, and joint geometry, on joint shearing resistance. While the interpretation of results was impaired by the data spread, it was possible to observe that the friction angle of the filled joint (1) decreases with increasing infill thickness, (2) increases with the introduction of larger fragments in the granular fill, (3) does not appear to be affected by the rock surface type. A suitable infill preparation technique for granular filled rock joints was also developed.