Spear Bolts and Sockets for Segment Tunnel Construction

We produce spear bolts and sockets used in segment tunnel construction. We also make heavy duty bolts and studs for structural steel field and steel construction buildings. In particular our production portfolio is formed of M24 bolts,M25bolts,M28 bolts at DIN 6914, 7990, 931, 933 norms and studs at ASTM norms (such as ASTM A 193 Gr B7 / B8).

Foundation Bolt ( J Bolt ) used in concrete foundations of  buildings, Stud Bolt, Barrage Cover Bolts, DIN 912 imbues, tailor-made,  special type, welded and  sleeved anchorages are available as well in our plant.

Functions

Spear bolts are a type of high-strength fastener used in tunnel construction to temporarily fix precast concrete segments together during the assembly of the tunnel ring and before the annulus grout hardens. Their primary functions include: 

• Delimiting Misalignments: The pointed or tapered end of the spear bolt helps to quickly and precisely align the initial longitudinal joints of the tunnel segments during the ring building process.

• Securing Ring Geometry: They help maintain the circular shape and overall geometry of the concrete ring until the grout injected into the gap between the ground and the tunnel lining sets and provides permanent structural support.

• Assisting in Segment Handling: They help hold segments of partially built rings together and support segment weight as the tunnel boring machine (TBM) advances.

• Ensuring Gasket Compression (Temporary): While not always effective at holding the joints closed under full, long-term gasket loads, they temporarily preserve the compression of the joint gaskets to ensure a waterproof seal during the initial construction phase. 

Key Characteristics

• Design: Spear bolts and their corresponding sockets are designed for quick and efficient single installation. They use a fast-thread design which allows them to be inserted much faster than traditional metric threads.

• Material and Finish: They are typically made from high-strength alloy steels (grades 5.8, 6.8, 8.8) and are often finished with galvanization or sherardization for corrosion resistance.

• Usage: They are considered temporary components whose main role is during the construction phase. Once the annular grout has fully hardened, the surrounding ground and the grout provide the permanent structural integrity, and the bolts become less critical for load bearing. 

Basic Information of  Our Spear Bolts and Sockets

Our spear bolts can be made of Q235, 35#, 45#, 35CrMo, 42CrMo, 40cr. The grade available can be 4.6, 4.8, 6.8, 8.8, 10.9,ect.  Our sockets (also known as dowels,sleeves,inserts) are available in various grades of plastic: plastic; polyamide or polypropylene.

Manufacturer & Supplier Of Spear Bolts and Sockets

Kunshan Signum Machinery Technology Co.,Ltd is able to supply  spear bolts and sockets for tunnel construction according to customers' requirements or drawing with competitive price.

Contact Us

Direct Line:+86 512 50353196

Whatsapp:+86 158 6266 4803

Email: admin@rail-fastening.com

Web: www.rail-fastening.com

Address: 120 Tongjing Road, Lujia Town, Kunshan, Jiangsu 215331, China 

You might be fascinated by