A self-drilling anchor is a type of bolt used to ensure the stability of the roof and walls in underground mining and tunnel construction. Unlike other types of bolts, self-drilling bolts do not require pre-drilling and can drill and hold at the same time.
These bolts are designed with a hollow threaded bar with a one-time use drill bit at its end, simplifying and reducing the installation process.
Once installed, they are filled with resin or cement mortar to consolidate the ground. In addition, these bolts can be joined by couplings to achieve lengths that would be impossible with other types of bolts.
At the end of the bolt, there is a nut that, once installed, is tightened, putting the bearing plate and the bolt itself under load, further increasing the bolt’s effectiveness.
Self-drilling anchors can also be used in areas where the rock is harder or more compact, using different types of bits. By drilling and securing at the same time, the need for additional equipment for pre-drilling is reduced, which also reduces cost and installation time.