Arc Hex Head Joint Bolt

                                                                       Metro Bolt for Segment Tunnel

What is Metro Bolt for Segment Tunnel？

Metro bolts used to repair the cement structure of the subway are called subway bolts. They are widely used in mining and subway engineering. There are two types of metro bolts: longitudinal straight bolts and circumferential arc bolts. In some projects, the specifications of 2 types of bolts are the same, while in others, they have different specifications and strength grades. Metro bolts also have another name. They are called segment tunnel bolts. There are various designs and types of segment bolts based on the diameter of the shield.

Arc-shaped segment tunnel bolt

Arc-shaped segment tunnel bolts are used to connect and fasten segments. These segments are assembled into a circular cylindrical pipeline, where the segments form the cylindrical walls. During excavation, arc-shaped segment bolts effectively control ground settlement, reduce the impact on above-ground structures, and ensure that underwater excavation does not affect surface traffic. Each segment is combined to form a pipeline, designed as straight or arc-shaped fastening connectors, which are called arc-shaped segment tunnel bolts.

Metro Segment Bolts Classification

Metro segment connection bolts have a wide range of applications, including building segment connections, shallow-buried longitudinal segment bolts, subway shield construction, subway segment connections, tunnel segment connections, and other projects requiring connection and fastening. Generally, segment connection bolts can be classified into 6 types: hexagonal head arc-shaped segment bolts, non-standard segment bolts, double-ended straight segment bolts, double-ended arc-shaped segment bolts, hexagonal flange face arc thread segment bolts, and hexagonal head arc thread segment bolts. Additionally, segment connection bolts can be classified based on the applied forces, typically categorized into three levels: 5.8 grade (material using Q235), 6.8 grade (material using 45#), and 8.8 grade (material using 40Cr). Zinc plating is commonly used for surface treatment.