Experimental Study of Bolt-Anchoring Mechanism for Bedded Rock Mass

Abstract

This study examined the effectiveness of different bolt anchoring systems in bedded rock to determine the bolt anchoring mechanism. The rock failure under shear and tensile stresses was evaluated. The results showed that bolt anchoring was achieved mainly by an anchoring agent restoring the bond of the rock surrounding the drill holes and the bolt body providing supporting resistance. The strength of the bedded rock increased with the anchoring effect. Full anchoring bolts were especially effective. In the absence of bolts, the failure mode of the rock changed from shear failure to splitting failure. With bolting, the failure plane was parallel to the bolt’s axis. Shearing began along the interface between the hard and soft rock beds. Compared with end-bolt anchoring, full-length bolt anchoring offered a superior anchoring effect by increasing the strength and shear-bearing capacity of the rock so that it could bear more load.