"Analysis of bolting failure in deep mining roadway and support counter" by Yiguo Ning, Shuangwen Ma et al.
Aiming at the problem of holt support failure caused by surrounding rock deformation in deep mining roadway,a method was pro¬posed to reduce the bolt breakage by improving the bolt stress state, changing the anchoring mode and optimizing the shape of rod body. On this basis, a new rebar anchor rod with a new shape and structurewas designed. Laboratory tests show thatthe average pull-out force of the right-hand bolt, the left-hand bolt and the high strength bolt with large rib spacings are 136.9 kN, 106.1 kN and 147.6 kN, andthe large-rib spacing high-strength bolts absorb energy better result...
Source: uow.edu.au