Characteristics & Advantages of Self-drilling Rock Bolts in Tunnel Support

A tunnel is a construction that is built underground, underwater, or in the mountain by laying a railway or highway to let motor vehicles pass through. Based on the site selection, the tunnel is divided into the mountain tunnel, submerged tunnel, and city tunnel. Because of the specificity of the location, its exploration and digging must be based on the surrounding terrain, geology, and the distribution of the underwater. To ensure the traffic capacity is smooth, we should reinforce and advance the pre-support of the tunnel when digging it.

Luoyang Sinorock Engineering Material Co., Ltd. is specialized in the development, production, and sales of anchoring products. The bolt productions in our company insist on being safe, efficient, energy-saving, and environmentally friendly, and we will provide one-stop service, integral solution, and quality guarantee.

When the tunnel is built in the terrain or the surrounding of broken rock, loose soil layer, and difficult to drill, the self-drilling anchor bolt can combine drilling, grouting, and anchoring into one step without casing pipe and drilling pipe, and then ensure the anchoring effort in the complicated geological condition. It owns the features of convenience, reliability, and high- efficiency.

What’s more, there are some other advantages when using self-drilling rock bolts in tunnel support.

1. Self-drilling anchor bolt system, which combines drilling, grouting, and anchoring together, is suitable for broken rock and conditions which are difficult to drill holes. Casing pipe is omitted in construction, which greatly improves construction efficiency.

2. Self-drilling anchor bolt system has a rich variety of drill bits, and the drill bit can be selected according to the properties of rock and soil, which can improve the drilling efficiency.

3. Self-drilling anchor bolt system can fill cracks, consolidate rock mass and soil layer through pressure grouting, and has good grouting spreading radius and reliable anchoring quality.

4. The hollow anchor bar can be cut arbitrarily and lengthened by the coupler. Therefore, the self-drilling anchor bolt is suitable for construction in a narrow space that large equipment cannot enter.

When the tunnel is influenced by the underwater, seawater or the chemical mediator, duplex coating rock bolt can come into play. This kind of production combines two different protecting ways together: hot-dip galvanizing and epoxy coating. Hot-dip galvanizing involves dipping the article with a chemically clean surface into a bath of molten zinc which reacts with the iron and forms a coating, and to prevent rusting; Epoxy coating doesn’t react with acid, or alkali. It has good chemical stability, ductility, and small dry shrinkage. And it can separate water, oxygen, chloride, and other corrosive media. Meanwhile, it also creates an electric insulation layer that can insulate the electric current between the steel bar and outside conditions, which can reach a good result in corrosion prevention.

Under the circumstance of weak and broken rocks, to prevent tunnel collapse, and rock deformation, and to ensure construction quality and the safety of workers, large- diameter pipe shed method is an ideal tool for supporting. Except for the basic parts: nut, coupler, drill bit, it has also the key parts: pipe shed body and domed plate.

In addition, the friction bolts can increase the contact area of the steel tube and the rock layer, which has a larger pulling-out force.

In a word, based on the different geological conditions, our company develops and makes different anchor bolt productions to reach the best effort and afford our customers the best one-stop service.