Tie Rod System of Arch Bridge

Installation and Protection Requirements for Tie Rods

A. Installation Requirements:

1. Strict management and monitoring between construction processes are required. The construction team must have the technical quality of tie rod and cable construction and master its construction process.

2. Sufficient installation and tensioning space must be guaranteed. During installation, the anchor must not be damaged by knocking or knocking, and the material of the cable must not be damaged or deformed.

3. The pre-buried pipeline must be smooth and unobstructed to avoid scratching the steel strand during use.

4. The cutting length should be accurately calculated, and the length of PE stripping should be strictly controlled. Avoid improper cornering of the steel strand causing the anchoring failure of the clip; for the replaceable tie rod, the length of the tie rod with PE entering the extension tube should be strictly controlled to ensure sufficient gripping force in the extension tube.

5. The exposed strands at the tensioning end and the fixed end should be cleaned of grease. Especially for the tie rods that need grouting, it is necessary to ensure that the surface of the strands is free of oil to avoid affecting the grip.

6. The anchor should be kept clean and no substances that affect its anchoring performance should be attached. Before installation, a small amount of anchor remover should be evenly applied to the outer cone surface of the clip or the inner wall of the cone hole of the anchor plate.

7. Ensure that the strands correspond to the unit hole positions of the anchor, the clips match the cone hole accurately, the clips and the strands bite evenly, the end faces of the clips are flush, the unevenness of the two ends is required to be less than 0.5mm, and the minimum use stress of the anchor is required to be greater than 0.11.

8. Before sealing the anchor, according to the design of the structure and tie rod characteristics, the corresponding excess strands should be neatly cut off with a grinder, and flame cutting should not be used.

B. Protection Requirements:

1. The steel strands should be kept clean to prevent dirt or corrosive substances from adhering to the exposed steel strands. After tensioning, protective grease should be injected for protection.

2. The surface of the free section cable body must not be damaged. If damaged, it must be repaired in time. No substances that corrode the cable body should be attached. Pay attention to fire prevention.

Ⅰ. The Cable Body of the Steel Strand Tie Rod

The cable body of steel strand tie rod is a fully anti-corrosion structure cable body, which has good anti-corrosion performance and can effectively solve the stress cracking problem of HDPE sheath. The cable body can be divided into two types: A and B. The cable body adopts finished cable, and its structural forms are A1, A2, B1, and B2. 

Type A is a finished cable body of smooth (or galvanized) steel strand; Type A1 cable body is a single-layer HDPE structure, and Type A2 cable body is a double-layer HDPE structure, using low-stress anti-corrosion cable body technology; Type B is an epoxy sprayed steel strand finished cable body, double-layer HDPE protection, and the inner layer HDPE is a non-bonded rib structure.

Ⅱ. Steel Strand Tie Rod Structure and Parameters

Steel strand tie rods can be divided into four types: 

replaceable rope tie rods, full anti-corrosion replaceable and adjustable tie rods, single steel strand replaceable rope tie rods, and permanent tie rods.

1. Replaceable Rope Tie Rod

Note: The cable body length is within 300m, the bent pre-buried pipe is relatively straight and short, and the straight pre-buried pipe meets the length requirement, so this structural form is selected.

2. Full Anti-corrosion Replaceable and Adjustable Tie Rod

Note: When the cable length is more than 300m, the bend and the embedded pipe are long and curved, and the straight embedded length is short, this structure is selected. The right sealing device has two independent waterproof structures, each waterproof structure can be independently waterproof, increasing the waterproof function, and the left sealing device is filled with oily wax or anti-corrosion oil to protect the anchoring area.

3. Single Steel Strand Replaceable Rope Tie Rod

Anchor size parameter          (Unit：mm)

4. Permanent Tie Rod

Packaging：

1) All the products are packed with seaworthy packing.
2) Customer's special requirement for packing can be satisfied.
3) Air freight, sea freight and truck freight are all available.