One of the principal and most basic safety concerns in underground mining is the solidity and stability of the roof under which men and machines work. Over many years a series of types and styles of means have been employed to stabilise and support the roofs of mine working tunnels. Over that time the means of providing such support have evolved to provide greater safety, durability and means of implementation. The articles which follow outline the main aspects of three stages of that development – starting with the ‘traditional’ means of support by means of vertical timber props holding up timber cross beams, with no penetration of the roof. This was followed by the development of ‘long bolts’ which were injected by drilling into the roofs, and provided strength through mechanically locking together the strata forming and overlying the roof. The approach then evolved into a form in which bolts were still drilled into the roof, but sophisticated high-strength adhesives were delivered with the bolts, and functioned to provide more broadly located binding of support within the roof structure.
The articles which follow describe the developments of these three means of support:
Pit props in underground mining
Chemical bonding for roof support anchors