Embedded Cast-in Channels for Rail Transit Utility Tunnels

Embedded cast-in channels (Hafen Channels) for rail transit utility tunnels refer to steel channel connecting elements pre-embedded during the construction of rail transit integrated utility tunnels or subway station structures. These channels are used to fix pipelines, cable trays, equipment supports, or other ancillary facilities. They are widely used in the electromechanical installation and pipeline fixation of rail transit due to their high strength, adjustability, and ease of construction.
A cast-in channel is a C-shaped steel component with serrated grooves, usually made of hot-rolled or cold-rolled steel plate, with a hot-dip galvanized or stainless steel surface. It has built-in T-bolts or special anchor bars for secure connection to the concrete structure. The embedded cast-in channel is installed in the formwork before concrete pouring and integrated with the structure after pouring.
 

Structure and Materials of Cast-in Channels

• Structural Composition：
  • Channel Body：C-shaped steel channel, common specifications are 40×22mm, 50×30mm, etc., with inwardly turned edges or toothed design to enhance the biting force of the T-bolt.
  • Anchor Bars：Welded to the back of the channel body (usually L-shaped or wavy steel bars) to ensure anchoring force with the concrete. The anchor bar diameter is generally 8-12mm.
  • T-bolts：Matched with the channel body, the bolt head is embedded in the channel, and the nut fixes the external components, with specifications such as M12 and M16.
  • Filler：Foam strips or plastic caps are used to fill the channel before pouring to prevent concrete from seeping in.
• Material Requirements：
  • Channel Body：Q235 or Q355 steel, hot-dip galvanized surface (coating thickness ≥55μm) or stainless steel (304/316), conforming to the "Technical Specification for Corrosion Protection of Steel Structures" (GB/T 25119-2010).
  • Anchor Bars：HPB300 or HRB400 steel bars, welding conforming to the "Code for Welding of Steel Structures" (GB50661-2011).
  • Load-bearing Capacity：Select the appropriate channel type and bolts according to the design load (such as 5kN-50kN/meter).