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Tunnel Segment Bolts for Railway, Metro Tunnel Segment Bolts

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SKU
Tunnel Bolts
SKU#: Tunnel Bolts

A tunnel segment bolt is a kind of special fastener used to link and fasten segments of shield tunneling machines during tunnel excavation. Through this kind of bolt connection, severkal arched segments can be connected into a circle, thereby supporting the entire tunnel surface. During excavation, the ground settlement can be effectively controlled, the impact on the ground buildings can be reduced, and the construction underwater can be effectively controlled. When digging, it does not affect the characteristics of water surface traffic. This kind of fastened connection piece designed as a straight line or a certain arc is called a tunnel bolt or segment bolt.

  1. Overview of Tunnel Segment Bolts

A tunnel segment bolt is a kind of special fastener used to link and fasten segments of shield tunneling machines during tunnel excavation. Through this kind of bolt connection, severkal arched segments can be connected into a circle, thereby supporting the entire tunnel surface. During excavation, the ground settlement can be effectively controlled, the impact on the ground buildings can be reduced, and the construction underwater can be effectively controlled. When digging, it does not affect the characteristics of water surface traffic. This kind of fastened connection piece designed as a straight line or a certain arc is called a tunnel bolt or segment bolt.

  1. Tunnel Segment BoltsType

According to various factors such as the size of the segment, the diameter of the shield tunneling machine, and the location of the tunnel where the segment is located, the design of segment bolts is also diverse. At present, the main types of tunnel segment bolts are:

(1) Double-headed straight tunnel segment bolts
(2)  Double-ended arc-shaped tunnel segment bolts
(3) Hexagonal arc tunnel segment bolts
(4)  Hexagon head arc threaded tunnel segment bolts
(5)  Hexagonal flange surface arc threaded tunnel segment bolts
(6) Non-standardtunnel segment bolts

  1. Grade, Material and Surface Treatment of Tunnel Segment Bolts

Tunnel segment bolts, like other bolts and fasteners, are designed with different strength levels according to the application environment and different forces.

The commonly used grades are: 5.8, 6.8, and 8.8.

The corresponding production materials are: Q235, 45# steel, 40Cr and other materials.

Common surface treatments for tunnel segment bolts include hot-dip galvanizing (hot-dip galvanizing), Dacromet (commonly known as zinc-based Chromate), powder sherardizing, multiple composite powder sherardizing, etc. The quality of the surface treatment of the tunnel segment bolts is very important. Because the tunnel segment bolts are installed underground, they play a role in connecting the segments. The environment where it is located in humid, which can easily cause corrosion of bolts and cause rust. Therefore, if the surface treatment of the bolt fails to meet the design requirements, causing the bolt to rust during use, the corrosion to the inside of the bolt will affect the mechanical properties and tensile strength of the bolt. In relatively harsh environments, composite coatings, such as thermal spray zinc alloy or powder sherardizing + zinc-based chromate + alkali-resistant coating, can be used to enhance the corrosion resistance and alkali resistance of the product.

4. The characteristics of tunnel segment bolts

The main feature of double-headed arc-shaped tunnel segment bolts is: compared with straight bolts, its arc-shaped form adds a bending process, such as improper process of the processing factory or the operator who does not pay attention to the details of the processing. It is easy to happen that the bolt cannot pass through the tube during installation due to the improper machining of the bolt radian. All arc-shaped products of Anyang Railway Equipment Co., Ltd. use molds to control the arc of the bolts, and each one passes the mold for inspection to ensure that each tunnel segment bolt that leaves the factory can pass through the segment smoothly. At the same time, it prevents the construction unit from During the construction process, it was found that the bolts could not pass through the segments, which affected the construction speed and helped the construction company reduce costs.

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Is this product buy America compliant? Yes
Brand AT