What Is a Screw Anchor?

Anchor bolts are often used to anchor various pipeline supports or as fasteners for connecting and installing various other items. Anchor bolts are now used to anchor machinery.

Anchor bolt is a kind of bolt, which is often used for anchoring anchor connection. It has been widely used in anchoring machinery and various pipe rack supports. It is easy to install on site. After installation, it can understand the load. It can be disassembled and reused when necessary. So it is a lot of bolts. ^[1]

Self-anchoring bolts were mainly used as anchors for various pipeline supports or as fasteners for connecting and installing various other objects, instead of being used for buried parts. Now it has begun to be used for anchoring equipment in China.

The self-anchoring bolt is made of the structure of the screw and cooperates with some special parts to make it expand in the bolt hole and anchor on the concrete foundation. Therefore, it is called self-anchoring bolt or expansion anchor bolt . Since this bolt must be installed in the drilled hole, it is also a drilling anchor bolt .

In addition to the general advantages of drilling anchor bolts, self-anchoring bolts are also very convenient to install on site. After installation, they can bear the design load immediately. If necessary, they can be removed from the bolt holes for replacement or reuse. However, the structure of this bolt is relatively complicated, there are many processing steps, and the dimensional accuracy of the bolt hole diameter is high (allowable error of the hole diameter is 0.5-2 mm).

Expansion anchor bolt, commonly known as tube expansion bolt . Expansion anchor bolts have been used in China for nearly 30 years. It not only shows the superiority of expansion anchor bolts, but also tests its effects, and its application scope is still expanding. The application of expansion anchor bolts not only accumulates a large amount of experience, but also makes many improvements in the anchoring process, both in terms of structural form and function. ^[2]

Determine the axial force that the anchor bolt can withstand in the limit state

And bending moment

It can be assumed that the anchor bolts cannot withstand the pressure. For the anchor bolts of the three configurations shown in Figure 6, the corresponding

The correlation curve is shown in Figure 7. In the picture

Designed for tensile strength of bolts. ^[3]

Image 6

Figure 7

According to Fig. 7, the correlation equation can be given as Fig. 8.

Figure 8 (2 photos)