Self-Drilling and Hollow Core rockbolts

Self-Drilling Anchors are hollow core rockbolts which serve as both the drill string during drilling of a support hole, and as the support tendon once grouted into place. A single use drill bit, selected to suit the ground condition, is fitted to the leading end of the SDA with a plate and nut fitted on the trailing end. Couplers can be used to combine SDA sections for extension bolting.

Hollow core bolts utilise the same hollow bar as SDAs but are supplied without a drill bit for applications where a convetional drill string can be used to drill the support hole. Once the HC Bolt is inserted into the pre-drilled support hole, resin or grout is injected through the bolt to complete the installation.

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Product Description

Self-drilling anchor bolts have a wide variety of fields of operation, including reinforcement of weak tunnel rock/ soil conditions, tunnel stabilization, tunnel root piling, and tunnel entrances.

Tunnel entrances, tunnel trenches, cut and cover areas, strengthening / stabilization of excavation routes, dams and slopes, as well as strengthening of retaining walls and noise barriers are other applications where self-drilling anchor bolts are used.

The rock bolt, which, in addition to its use in foundation piles and support piles, can also be used as an avalanche safety shield, provides extensive solutions for users.

The threaded hollow bars provide comprehensive solutions for tunneling and mining industry growth.

Self-Drilling and Hollow Core rockbolts

Composition

Self drilling anchor bolts from JIUFU Anchoring Systems consists of:

1. A hexagonal nut

2. A bearing plate

3. Extension couplings, if the anchor consists of several anchor rod sections

4. Hollow anchor rod(s)

5. A sacrificial drill bit

6. Grout Coupling

Installation

1. Preparation

Do some checking, including if the drilling rig works, whether anchor body is unblocked, and so on.

Select a proper drill bit according to the following factors: service life, maximum length of anchor body, geological condition, geometry.

2. Drill and Grout Simultaneously

Connect the grouting pipe with the rotary grouting adapter and open the grouting machine, it will automatically simultaneously grout when drilling.

This is the feature of self drilling anchor rock bolt differing from other traditional solid anchor bar. It is no risk of hole collapsing when drilling in the unstable rock and soil mass.

3. Extend Anchor Body

With the coupler, it is possible to extend the anchor body to meet the required drilling depth. All you need to do is just screwing the coupler on the end of an anchor body by your hand.

4. Install Plate and Nut

After the slurry curdles, install the plate and nut.

Advantages

1. It features a hollow bore for flushing, or simultaneous drilling and grouting.

2. Reliable, efficient and convenient.

3. Choice of drill bits for different ground conditions.

4. It can be elongated by using couplers.

5. Suitable for anchoring in broken geological condition and narrow space, which has achieved perfect effect.