Self-drilling Anchor Bolts: 3 Applications and 5 Advantages Must Know About!

by Anna S. Optimization Specialist

Geotechnical anchorage is an important branch in the field of geotechnical engineering. Using anchorage technology in geotechnical engineering can fully improve the strength and stability of soil mass. As a new type of highly efficient construction material in the field of rock and soil anchorage, self-drilling anchor bolt has been widely used in various fields abroad. This article will introduce the three most prominent applications and five advantages of the self-drilling anchor bolt.

Three Common Applications of Self-drilling Anchor Bolts

1. Slope Stabilization

The reinforcement method of combining high-strength self-drilling hollow bolts and full-length bonded bolts is generally adopted for transportation, water conservancy, hydropower, and urban rock and soil slope engineering, especially high slope protection with excavation height greater than 30m. This method can maintain slope stability by strengthening the system and local soil mass.

2. Tunnel and Underground

In tunnel and underground engineering, self-drilling hollow bolt, mortar bolt, and reinforced shotcrete have become common methods to maintain the stability of surrounding rock. This method can effectively reduce the subsidence of the vault and the displacement of the side wall, ensure the stability of the cavern, and the safety of construction personnel.

3. Ground and Foundation

The self-drilling hollow bolt is widely used as the supporting structure of pile foundations in city building foundations. Usually, there are strict requirements on the ultimate pulling force and drilling depth of the anchor bar used in foundation construction. The maximum pullout resistance of the large-diameter self-drilling hollow bar can reach 1900kN, which can ensure the stability of the foundation and the superstructure.

l Hydraulic and Hydropower Dam Body Engineering

In dam engineering, the use of self-drilling rock bolts to fasten the dam body to the bedrock can strengthen or raise the dam body without interrupting the work progress, resulting in significant savings in construction costs. The design tensile load of the anchors used to strengthen the dam body is usually large to withstand the impact of flooding.

l Anti-floating Engineering

Self-drilling hollow anchors are used as anti-floating anchors in basement anti-floating projects, which can improve the utilization of soil strength and durability of anchors. There are various types of floatation anchors and different ways of arrangement: centralized point arrangement, centralized line arrangement, and uniform surface arrangement.

Five Advantages of Self-drilling Anchor Bolts

1. Suitable for all kinds of geological conditions.

It is especially effective in complex geological conditions, such as geology prone to collapse holes.

2. Drilling depth without restriction.

Due to the limitation of existing anchor materials and drilling equipment, the drilling depth of conventional anchor bolts is shallow, but the drilling depth of self-drilling anchor bolts can be much deeper due to the low drilling resistance, and the current drilling depth of self-drilling anchor bolts is 18m according to the Sinorock project report.

3. Suitable for construction in confined spaces.

Self-drilling anchor bolts can be cut or extended in single rod lengths of 2m, 3m, 4m, and 6m as required.

4. Simple process.

Self-drilling anchor bolts simplify the process and speed up the construction by completing drilling, grouting, and anchoring at one time.

5. Stabilize the hole wall.

The cement slurry with a water-cement ratio of 0.4~0.5 is supplied under pressure by the grouting machine while drilling. The slurry can be quickly filled and absorbed by the cracks of the borehole and the geotechnical body to ensure the stability of the borehole wall.

Summary

The above is an introduction to the application and advantages of self-drilling anchor bolts. By switching to self-drilling anchor bolts for construction in special strata, the construction process is more time-saving and labor-saving. If you have any questions about self-drilling anchor bolt system or geotechnical anchorage, please contact sinorock@sinorockco.com. As a professional self-drilling anchor manufacturer, Sinorock will provide you with detailed product information and free quotation.

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