Subway Steel Lattice Columns - Steel Structural Components

Subway steel lattice columns (steel lattice composite columns) are commonly used steel structural components in deep foundation pit support and reverse construction methods for subway stations. They are mainly used to support the foundation pit retaining structure or the main structure of the station, bear the upper load, and transfer it to the lower foundation (such as uplift piles). Steel lattice columns (or lattice composite columns) are usually composed of multiple angle steels, channel steels, or H-beams welded together with lacing bars, forming a spatial frame structure, with a common cross-section being square (e.g., 600×600mm). The lower part is usually connected to bored piles (uplift piles) to form a column-pile foundation.
 

• Structural Composition:
  • Main Materials: Commonly 4 L-shaped angle steels (e.g., L200×20) or H-beams, connected by welding lacing bars (steel plates) to form a lattice frame.
  • Foundation: The lower part is connected to bored piles (usually 800-1500mm in diameter), with the pile body extending deep into stable strata (such as silty clay or weathered rock).
  • Connection Method: Manual arc welding or gas shielded welding, and the weld must comply with standards such as the "Code for Welding of Steel Structures" (GB50661-2011).
• Material Requirements:
  • The steel must have sufficient strength and corrosion resistance, commonly Q235 or Q355 steel.
  • In environments with strong groundwater corrosivity, anti-corrosion treatment of the steel structure (such as coating or hot-dip galvanizing) needs to be considered.