The problems and countermeasures of mining friction bolt (split sets bolt) support in practical application (B)

3 Mining Friction Bolt manufacture process:

Process flow: do a good job of knocking on the top→clicking the eye→punching the eye→blowing the eye→installing

4 Problems with mining Friction Bolt support in practical application

4.1 Quality tracking is not in place. The construction quality management system is not perfect, and the technical quality of the employees is low. Some employees use hammers to make the diameter thin and the seam width smaller; some simply saw off one section of the anchor rod. Although the installation speed of the anchor rod is accelerated, the anchor is fixed. The force is low and the top plate cannot be controlled well. This phenomenon is caused by subjective reasons and is very detrimental to safety in production.

4.2 When the drill bit is severely worn, replace it without care, resulting in a smaller hole diameter. Or when replacing the drill bit, you didn't pay attention to drilling with a big drill bit. Due to the higher requirements for the hole diameter of the mining friction bolt, sometimes the hole diameter is too large, which will cause the failure of the bolt support; when the hole diameter of the bolt is too small, it is easy to cause the mining friction bolt to fail to complete. Long drive into the bolt eye, leaving a section out of the hole, if it cannot be pulled out, waste rods are generated, thus wasting supporting materials.

4.3 The bolt eye is not drilled through the layer according to the position of the eye. When the staff drilled the bolt holes, they did not pass through the layer to construct the bolt holes according to the position of the holes, which caused the anchor bolts installed to fail to meet the design support requirements.

5 Main countermeasures adopted in practical application of mining friction bolt support

5.1 Strengthen staff training, improve technical quality, and implement quality follow-up guidance. First of all, regular training courses for tunnel friction bolt support are held to let employees understand the principle of friction bolt support; secondly, the construction personnel must strengthen the implementation of the targeted operating procedures and construction measures prepared by the construction personnel for the operation point to improve The technical quality and operational level of the staff analyzed the consequences of not following the operating rules and construction measures, opportunistic and cost-saving, so that they fully realized that the unqualified Anchor Bolt eye should not only be punished, but also the unqualified anchor must be installed. Threats and consequences to the roadway support and the safety of construction workers after the pole. At the same time, strengthened daily inspections and found that the bolt holes for drilling bolt holes that did not strictly follow the operating regulations of the supporting drilling tools and the design parameters of the roadway support should not be installed with pipe friction bolts, and construction should be stopped in time, and rectification should be carried out as required.

5.2 The mine has established a fully dynamic anchor construction quality supervision mechanism, and the quality of the project is linked to wages. The quality supervisor should periodically check the construction quality for anchoring force testing, and report quality information in time; the construction unit establishes a quality account and checks and accepts statistics for shifts. If there is a problem with the friction bolt rod, the responsible person can be traced to the account by checking the account.

5.3 Strictly follow the position of the eye to drill through the layers of the friction bolt eye. Drill holes strictly according to the position of the bolt holes pointed by the technicians, and as far as possible to drill the holes perpendicular to the bedding surface; if there is a rock face with a concave and convex surface on the top side, the bolt holes are arranged in the groove position; if the surrounding rock of the roadway is unstable, The row and spacing of friction bolts should be appropriately reduced; the holes of the bolts should be 5-10cm deeper than the length of the bolts.

6 Conclusion

Friction bolt support is an effective roadway support method that actively maintains the stability of the surrounding rock. The existing problems are found in practical applications through slotted bolts, and effective countermeasures are taken. The support effect of the roadway is effectively improved, and the construction of rapid excavation is also realized, and good economic benefits are obtained.