How to use self-drilling hollow anchor bolts to deal withTunnel roof collapse

The top priority of tunnel construction is to ensure stable and safe operation in the later period, which is inseparable from the handling of various problems during the construction process. Tunnel roof collapse is a serious problem. The main reasons include excessive water content in groundwater, loose and broken construction geology, etc. The following mainly talks about how to deal with tunnel roof collapse.

1. Gravel cleaning

Use an excavator to clean up the gravel or soil on the collapsed tunnel face. When cleaning, you need to pay attention to the changes in the vault and surrounding rock mass to avoid secondary collapse. Different treatment methods are selected according to the size of the collapse. Temporary supports can be erected for small collapses, while grouting reinforcement is required for large collapses.

2. Shotcrete

After clearing the landslide, spray concrete on the tunnel face and seal the rock surface around the cave to prevent another landslide in the cave during secondary excavation. If the geological conditions are relatively poor, measures such as anchoring and grouting reinforcement need to be taken.

3. Anchor drilling

For rock masses that have already collapsed, reinforcement and support must be carried out during re-construction. Traditional tunnel support mostly adopts the support method of drilling with pipes. The construction efficiency of the new self-drilling hollow grouting anchors is faster, eliminating the need for casing, and can realize the function of drilling and grouting at the same time.

4. Drilling and grouting are carried out simultaneously

The self-drilling hollow grouting anchor can be used with a special drilling rig to be used in various loose and broken formations. Grouting can appropriately expand the hole diameter during drilling, thus improving the pull-out force and bearing capacity, and achieving better hole formation and force value effects. Better than other reinforcements.

Tunnel roof collapse will have considerable harm and impact on the construction period, cost, personal safety and quality safety of the project. Project safety issues need to be controlled by specialists. From the strict requirements in terms of design, materials, construction, etc., to prevent the occurrence of problems such as roof collapse, the purpose of the research and development of HENGLONG self-drilling anchor bolts is to make geotechnical anchoring faster, more economical, and safer!