Cable bolting is an established procedure employed for the reinforcement of rock in underground mining. Cable bolts are long, totally grouted, and untensioned reinforcing tools.

The main purpose of using cable bolting is to make the shear and tensile mass of the rock better. The technique is frequently used in underground mining as safety standards have become higher and mining environments tougher.

 

What Are Cable Bolts?

Cable bolts are steel bars threaded together. They are installed during excavation to stabilise rocks and safeguard workers and machinery.

A drilled anchor or nail is fixed into the rock, grouted properly, and finally post-tensioned through compression and faceplates. The tension is crucial for distributing the load properly onto the nearby rock.

The method is similar to using a soil nail or soil anchors. Cable bolts essentially hold together fractured, unstable, or jointed rock. This results in passive resistance to form a more stable rock surface.

 

Why Is Cable Bolting Done?

Cable bolts were a game-changer in the mining and excavation industries. They have evolved with time to become cost-effective and easy to install. Cable bolting is important for keeping rocks in place and ensuring the safety of people and equipment inside the mines. Rock bolting aids corrosion protection to prevent rock displacement. It keeps rocks from fracturing or falling on workers, adventurers or travellers.

Cable bolting is used for both temporary and permanent rock stabilization. They enable tensioning without tensioners. Cable bolts feature a free length or threaded anchorage rather than the more common barrel and wedge technique. This results in a more flexible method, even when working with longer cable bolts.

Cable bolts have a high load-bearing capacity and low bolt weight. They can be installed using resin cartridges, injection resin, cement grout, or cement cartridges. Cable bolting is ideal for use in a limited space.

 

Rock Bolting Over the Years

The use of rock bolts was first recorded during the 1890s. More reliable documentation began in the 1920s. The St. Joseph Lead Mine in Missouri, United States has a rich history of using rock bolts. With time, rock bolting began to be used extensively in both mines and civil tunnelling projects in the US and Australia during the 1940s. In 1947, Australian engineers began to test rock bolts as long as four metres.

 

These engineers were involved with a complex for irrigation and hydroelectricity in south-east Australia. In the present day, cable bolts are widely used in different excavation projects. Deep underground mining can sometimes result in rock failures. Cable bolting is effective for preventing rock displacement and reinforcing the anchoring structure underground.

At Mining & Civil Integrity Testing, we specialise in Cable Bold Non-Destructive Testing equipment to measure cable length and spot issues in the grout column of cable bolts. Click here to contact us today.