Shear testing of rock bolts for hard rock mining

The shear capacity of hollow rock bolts is questionable due to the lack of experimental data. To address this limitation, the shear strength of three different types of hollow bolts, including “X”, “S” and “E” grade rock bolts were studied using the double shear test method under hard rock conditions. The outcomes revealed that the shear force depends on the bolt type. The “X” grade hollow bolt can tolerate larger vertical movement and shear force. In addition, it was found that the shear load capacity of hollow bolts is not necessarily around 70% of UTS. The results showed that the “X” and “S” grade bolts are more brittle due to their higher UTS and lower elongation capacity.