Roof anchorage is a method of inserting metal rods into the roof of a mine to prevent the roof from collapsing. The introduction of mining roof bolts in the 1940 led to the standardization of roof support systems that could not be destroyed by blasting. Therefore, mining roof bolts help to significantly reduce roof fall fatalities in underground coal mines.
Mining roof bolts are long bolts used to stabilize rock excavations in tunnels or rock cutting. It transfers the load from the unstable exterior to the confined and stronger interior of the rock mass.
Mine roof bolt is the most basic component of coal mine roadway support. It plays a vital role in strengthening the surrounding rock and ensuring the support of the surrounding rock itself. Mining roof bolts are used in mines and engineering technology to strengthen the main body of slopes, tunnels and dams.
Mining roof bolts are almost always installed in some way. The design of this pattern depends on rock quality and excavation type. Mining roof bolts are an important part of tunneling methods.
Mining roof bolts work by "weaving" the rock mass together before it can move enough to loosen and fail by breaking apart piece by piece. Mining roof bolts can also be used to support the wire mesh.
Mine roof bolt body can be divided into free section and anchor section. In the free section, the tension at the bolt head is transferred to the anchored section. The anchoring section refers to the area where the cement slurry bonds the prestressed tendons to the soil layer. Its function is to increase the bonding friction between the mining roof bolt and the soil layer, and increase the anchoring pressure of the mining roof bolt.