Tie Rods / PC Steel Bars (Civil Engineering – Harbor and River Works)
Essential tensile members for sheet pile construction
In harbor works, they are used for the foundations of quay walls and breakwaters; in river works, they are used for the foundations of sluice gates and protective walls. They are intended to serve as tensile members between sheet piles in steel sheet pile methods, steel pipe sheet pile methods, and double steel sheet pile wall methods.
Mild-Steel Tie Rods
These tension rods (tie rods) are manufactured using mild steel, such as SS materials, as the main material. Because they are not particularly high in strength, they cannot bear very large loads. However, they can be manufactured down to small diameters (small cross sections), making them the most common and widely used type.
| Category | Material | Yield Point | Tensile Strength | Size | Remarks |
|---|---|---|---|---|---|
| (N／mm2) | (N／mm2) | ||||
| Mild-Steel Tension Rods (Tie Rods) | SS400 | 245（235,215）and above | 400～510 | Φ12～100 | |
| SS490 | 285（275,255）and above | 490～610 | Φ12～100 | ||
| SNR400A | 235（215）～355（335） | 400～510 | Φ16～100 | ||
| SNR490B | 325（295）～445（415） | 490～610 | Φ16～100 |
High-Tensile Steel Tie Rods
These tension rods (tie rods) are used when a larger load than mild steel can support is required. They are manufactured using manganese steel. The two common classes are F-value 45 kg/mm² class and 54 kg/mm² class. Sizes range from φ25 to φ90.
| Category | Material | Yield Point | Tensile Strength | Size | Remarks |
|---|---|---|---|---|---|
| (N／mm2) | (N／mm2) | ||||
| high-tensile steel tension rods (tie rods) | THA690 (440 N／mm2級) |
440and above | 690and above | Φ25～90 | |
| THA740 (540 N／mm2Grade) |
540and above | 740and above | Φ25～90 |
PC Steel Bars
These tension rods (tie rods) are manufactured using materials with higher strength than high-tensile steel tension rods (tie rods). While they offer high strength, there are restrictions in use, such as low elongation and the inability to apply plating. Sizes range from φ9 to φ40.
| Category | Material | Symbol | Proof Stress | Tensile Strength | Size | Remarks |
|---|---|---|---|---|---|---|
| (N／mm2) | (N／mm2) | |||||
| PC Steel Bars | Class A, No. 2 | SBPR 785/1030 |
785and above | 1030and above | Φ10～40 | |
| Class B, No. 1 | SBPR 930/1080 |
930and above | 1080and above | Φ10～40 | ||
| Class C, No. 1 | SBPR 1080/1230 |
1080and above | 1230and above | Φ10～40 |
