A ROCK BOLT FOR REINFORCING ROCK STRATA IN A ROOF OR SIDE OF MINE OR TUNNEL

摘要

In the present invention there is provided a rock bolt useful for reinforcing several rock strata in a mine or tunnel roof or side, which comprises in combination a rock bolt, bearing plate and a nut. The combination consisting of an elongated cylindrical rod the peripheral body of which being provided along its length with a plurality of pairs of pointed and inclined web protrusions placed diametrically opposite to each other. The protrusions in form of elongated stud or a web act as guides to align the bolt inside a hole in a multi-layered rock strata and enable tearing of polyethylene packets of grout material into shreds, mix the grout material uniformly and distribute the grout material uniformly along the annular space. The elongated cylindrical rod is having a pointed upper end and a threaded lower end. The threaded portion of the said rod being provided with a removable co-centric bearing plate having a central hole of diameter less than the rod but more than the threaded portion, thus ensuring proper alignment of the bolt in a previously drilled bore-hole This enables holding of the bolt straight in a borehole in the rock layers and thereby ensure a uniform grout distribution in the annular space between the bolt and the rock. The threaded portion being provided with at least one removable nut having peripheral diameter greater than the central hole of the said bearing plate. This bolt will be able to hold and stitch multi rock layers when used in combination with a known grouting medium, which may be composed of cement or resin. The rock bolt of the present invention is simple to manufacture, easy to install and cheaper in cost.