摘要 |
The bail-type expanding shell rockbolt comprises a shell with a bail (10) including depending bail arms (20), and leaves (14) which are adapted to engage the wall of a hole which has been drilled into a rock formation. The bail arms (20) are fixed to internal surfaces of the leaves (14) at positions (28) which are spaced from the inner ends of the leaves to allow the inner ends of the leaves (14) to be splayed apart from one another. As a result of the fixture of the bail arms (20) to the internal surfaces of the leaves there is no reduction in the effective area of the leaves. |