Introduction
With the rapid development of the economy and the booming construction industry, more and more engineering projects need to establish themselves on the mountains. However, landslides and collapses have become significant challenges for these projects. To solve these problems, various slope support technologies have emerged, among which self-drilling anchor bolts have been widely used in slope support projects in recent years due to their unique advantages. This article will describe in detail the application and advantages of self-drilling anchor bolts in slopes.
Understanding self-drilling anchor bolts
Self-drilling anchor bolts are multifunctional anchors that integrate drilling, grouting, and anchoring functions. Self-drilling anchor bolt consists of six major components: hollow anchor bar, drill bit, coupler, plate, nut, and centralizer. In actual use, self-drilling anchor bolts can act as drill rods for drilling, and their hollow structures can also be used as grouting pipes to achieve grouting anchoring. This design greatly simplifies the construction process and improves construction efficiency.
Structural features:
Hollow anchor bar: it combines an anchor rod with a drill pipe and has the dual function of drilling and grouting.
- Drill bit: the drill bit is made of wear-resistant metal and has a slurry outlet, according to the geotechnical conditions to choose different models.
- Coupler: the coupler is a rod extension part, and it is of equal strength to the hollow anchor bar. The coupler can seamlessly connect the two rods, and there will be no grout leakage when grouting.
- Plate: the plate is installed at the tail of the anchor bar, between the nut and the rock formation.
- Nut: the nut is a device with internal threads that transmit the anchoring force of the hollow anchor bar to the plate and lock it in place.
- Centralizer: the center is a component used to realize that the hollow anchor body is positioned in the middle of the hole. It is installed on the hollow anchor body and lies in front of the connection sleeve to center the hollow anchor body.
Technical features:
- Multifunctionality: it integrates drilling, grouting, and anchoring functions, convenient and efficient construction.
- Strong adaptability: suitable for many complex soil and rock layers, especially in loose rock and soil layers.
- Flexible structure: the length of the rod can be flexibly adjusted, and the extension feature makes it more flexible and changeable in construction.
- Economical and efficient: compared with traditional construction technology, self-drilling anchor bolts can significantly save material costs and construction time.
Application example of self-drilling anchor bolts in slope engineering
Take a highway slope support project as an example. The project is located in a severely weathered area. The upper soil layer is broken and prone to collapse, making construction difficult. To ensure slope stability, self-drilling anchor bolts are used for support.
Project overview:
- Slope height: slope above the hole face.
- Anchor rod length: 6m.
- Anchor rod spacing: 1.5m×1.5m.
- Inclination: 20°.
- Reinforcement mesh laying: φ8@20cm×20cm.
- Sprayed concrete thickness: 15cm, strength grade C25.
Construction process:
- Preparation work: build a construction access road and set up a working platform or scaffolding.
- Drilling: use a down-the-hole drill, connect the anchor rod and the drill bit, adjust the drilling angle, and gradually drill to the designed depth.
- Clean the hole: use wind pressure to flush the drill hole and remove dust.
- Grouting: connect the grouting pump, prepare cement slurry, and inject it into the borehole until the slurry is complete and the pressure reaches the design value.
- Anchoring: install the domed plate and spherical nut to fix the anchor rod.
- Cleaning the site: after completing all construction, clean the site.
Notes:
- Ensure that the specifications, dimensions, and materials of the anchor rod meet the design requirements.
- Accurately grasp the construction site conditions and select the appropriate anchor rod model, drill bit, and grouting parameters.
- Pay attention to controlling the grouting quality and ensure that the slurry diffusion radius and grouting pressure meet the design requirements.
Advantages of self-drilling anchor bolts in slope support
- Improve construction efficiency: self-drilling anchor bolts integrate drilling, grouting, and anchoring functions, greatly simplifying the construction process and shortening the construction period.
- Enhanced support effect: during the grouting process, the slurry can fill the loose soil around the anchor, expand the diameter of the anchor, and improve the bearing capacity of the reinforcement.
- Adapt to complex environments: in loose and broken rock and soil layers, self-drilling anchor bolts can effectively overcome the difficulties of drilling and grouting with traditional anchors.
- Reduce costs: compared with traditional construction techniques, self-drilling anchor bolts can significantly save material and labor costs and improve economic benefits.
Conclusion
As a new type of slope support technology, self-drilling anchor bolts have shown significant advantages in solving geological disasters such as mountain collapses and landslides. Its application in slope support projects improves construction efficiency, enhances the support effect, and reduces construction costs. With continuous development and improvement of technology, self-drilling anchor bolts will play a more vital role in future slope support projects. We believe that this promising technology will play a more significant role in future social construction activities.
