In the field of modern infrastructure construction, the emergence of every innovative technology serves as a crucial juncture for breaking through the bottlenecks of complex engineering projects. It paves the way for new development paths in the industry and facilitates the resolution of long-standing technical challenges.

The self drilling anchor bolt technology, after years of exploration and practice, has now reached a highly mature stage. With its outstanding performance and wide-ranging applicability, this technology has been successfully applied in numerous engineering projects around the world, effectively propelling the smooth implementation of various construction tasks. So, what role exactly does the self drilling anchor bolt play in practical engineering projects that make it the preferred choice for so many projects?

What is the Self Drilling Anchor Bolt?

Before understanding what is the use of a self drilling anchor bolt, we must first clarify what is the self drilling anchor bolt. Simply put, self drilling anchor bolts are innovative anchoring materials primarily used in challenging geological conditions such as weathered rock, gravel layers, backfill soil, and sandy strata where conventional drilling methods struggle to form stable boreholes. Integrating drilling, grouting, and anchoring into one process, these bolts consist of a hollow anchor bar, coupler, nut, plate, drill bit, and centralizer.

What is the Use of Self Drilling Anchor Bolt?

The core function of the self drilling anchor bolt lies in efficiently solving the anchoring problems in complex strata. It adopts an integrated design of “drilling and anchoring simultaneously”, eliminating the need for pre-drilling. It can directly drill into loose and easily collapsible strata such as weathered rock, gravel layers, and backfill soil, and complete grouting and anchoring simultaneously, significantly improving construction efficiency. In the strata where hole formation is difficult, the drill bit and the anchor body work in tandem, effectively avoiding the risk of hole collapse and ensuring the quality of anchoring.

Next, its specific applications will be analyzed in detail from three main application scenarios:  the slope stabilization, the foundation , and the underground.

The Slope Stabilization

The self drilling anchor bolt plays a pivotal role in the field of slope support, leveraging its unique engineering features and remarkable technical advantages. Slope support is primarily applied to vertical or inclined surfaces, with the goal of safeguarding slope stability.

In slope stabilization projects, regardless of whether it is a soil slope or a rock slope, it can provide precise reinforcement and support tailored to different geological conditions. In retaining wall structures, it offers a powerful anchoring force to the retaining wall, preventing displacement or collapse caused by lateral soil pressure. For embankment stabilization and cutting reinforcement, the self drilling anchor bolt is equally crucial, ensuring the safe passage of roads in diverse complex terrains and under various weather conditions.

The Foundation

When applied in foundation engineering, the self drilling anchor bolt can, by virtue of its hollow structure for grouting and the ability to drill and anchor simultaneously, efficiently transfer pressure, tension, or cyclic loads to the surrounding soil. This load transfer mechanism, successfully transmits structural loads to the underlying foundation structure, thereby effectively restricting building deformation.

In foundation reinforcement projects, for soft foundations or those with potential uneven settlement risks, the self drilling anchor bolt can strengthen the soil through grouting, enhancing the foundation’s bearing capacity to meet the load requirements of buildings. For the reinforcement of old buildings, it can make up for the shortcomings of the original foundation, enhance the overall stability of the building, and extend its service life.

The Underground

The self drilling anchor bolt is also of great significance in tunnel and underground engineering, particularly in ultra-early-stage support. The self drilling anchor bolt can penetrate deep into the soil and conduct high-pressure grouting through its hollow structure. During the grouting process, the grout permeates and diffuses into the surrounding soil under high pressure, integrating closely with the soil. It’s as if numerous “steel bars” are formed within the soil, strengthening the soil radially and significantly improving its strength and stability.

The soil reinforced by the self drilling anchor bolt can effectively withstand various stress changes during tunnel excavation, thus effectively ensuring the stability of the surface of underground engineering. In advanced support operations, the self drilling anchor bolt, as a vital advanced reinforcement measure, reinforces the soil in front of the tunnel face before excavation, creating conditions for subsequent safe excavation.

Through an in-depth analysis of the application scenarios of self drilling anchor bolts, we have gained a clearer understanding of their practical uses. Now, let us shift our focus to the comparison between self drilling anchor bolts and conventional anchor systems, delving into the distinct advantages of self drilling technology to facilitate optimal selection across diverse engineering contexts.

What are the advantages of self-drilling rock bolts compared to conventional rock bolts?

1. They are suitable for various geotechnical geological conditions, such as geological conditions with collapsed boreholes.

2. There is no limit to the drilling depth. Due to the small drilling resistance of self-drilling anchor bolts, the drilling depth is greater than that of conventional anchor bolts.

3. They are suitable for construction in narrow spaces. The length of a single self-drilling anchor bolt body can be cut or extended as required. Common specifications are 3m, 4m, and 6m.

4. The process flow is simple. The self-drilling anchor bolt completes drilling, grouting, and anchoring in a single drilling operation, which simplifies the process flow and speeds up the construction progress.

5. They are beneficial for stabilizing the borehole wall. A screw grouting machine is used while drilling, enabling the grout to quickly fill the drilling holes and the cracks in the rock and soil mass, and be absorbed and solidified by the borehole wall to ensure the stability of the borehole wall.

Summary

Previously, we have thoroughly analyzed the functions of anchor bolts from three aspects: the definition of the self drilling anchor bolts, their practical application scenarios, and their unique advantages. We believe that you now have a relatively clear understanding of the applications of the self drilling anchor bolts. With the continuous progress of science and technology and the continuous improvement and upgrading of products, the application prospects of the self drilling anchor bolt technology will be even broader. The innovative “drilling-grouting-anchoring” integrated design of self drilling anchor bolts overcomes challenges in complex strata. Their dynamic grouting technology and adaptability to diverse conditions drive a paradigm shift in geotechnical engineering—from passive reinforcement to active support—providing reliable solutions for urbanization and infrastructure development.

In the future, it will not only enter more new fields but also take root in a wider range of countries and regions, continuously contributing to the global infrastructure construction cause and promoting the construction engineering industry to a new height of development.