What Are the Applications of the Four-piece Anchor System in Bridge Construction?

In prestressed construction, the four-piece anchor system (anchor ring, clip, anchor plate, and spiral reinforcement) serves as the core component for securing prestressed bridge structures. It is primarily used in post-tensioned prestressed structures. Its application covers key areas of bridge construction, directly impacting the structure's load-bearing capacity, stability, and durability. It also effectively controls deformation and cracking, ensuring safe bridge operation. Our anchor systems strictly adhere to relevant standards, combining high quality with affordable pricing. The main applications and functions of anchors in bridge construction are as follows:

1. Beams (precast and cast-in-place)

- Application: Beam ends or mid-span anchorage areas for prestressed tendons in simply supported beams, continuous beams, T-beams, and box beams.

- Function:

After the bridge steel strands are tensioned to the design stress by jacks, the clips retract with the strands and embed into the tapered holes of the anchor plate, forming a self-locking anchor unit. The anchor ring and clips lock the prestressed tendons, ensuring long-term and effective prestress transfer to the beam and preventing retraction.

The anchor pad, located between the anchor plate and the concrete, evenly distributes the intense concentrated force transmitted by the anchor, preventing concrete crushing in critical areas of the bridge (such as beam ends).

The spiral reinforcement wrapped around the anchor head enhances the compressive strength of the concrete in the anchorage area and reduces the risk of cracking.

2. Connections

- Application: Anchorage points between stay cables, suspenders, towers, and main beams.

- Function:

These points bear significant axial tension, and anchor rings and clips must securely lock the cables to ensure stable force transmission.

The anchor pads distribute the tension into the concrete structure of the tower or main beam, while the spiral reinforcement resists radial splitting forces at the joints, preventing concrete damage caused by high stress and ensuring the long-term reliability of the cable-to-beam/tower connection.

3. Bearing Area

- Application: Prestressed seismic bearings and temporary anchorage areas on some bridges.

- Function:

During earthquakes or thermal deformation, the four-piece anchorage system controls the expansion and contraction of the prestressed tendons through stable anchoring, cooperating with the bearings to buffer structural displacement.

The spiral reinforcement enhances the ductility of the concrete in the anchorage area, reducing the risk of brittle failure under seismic loads, thereby protecting the bridge.

Summary

The four-piece anchor system is the core of the "transfer-distribution-restraint" prestressing system in bridge construction. From beams to pylons, from static load-bearing to dynamic seismic resistance, its synergistic effect is crucial to ensuring the stability and safety of bridge structures. It is an indispensable component in modern bridge engineering. By precisely transferring prestress into the concrete, it significantly enhances the bending and shear resistance and overall stiffness of bridge beams, piers, and other components, extending their service life. It is widely used in highway bridges, railway bridges, urban interchanges, and long-span cable-stayed bridges. It can also meet auxiliary reinforcement needs such as slope support. 

If you have any specific needs, please contact us for customized anchor systems. We will provide you with the right products and guarantee after-sales service. Please feel free to contact us directly by email or phone!