A diaphragm wall is a reinforced concrete wall constructed in the ground using underslurry techniques.  Walls with widths of between 300mm and 1500mm can be formed in this way to depths in excess of 60 metres.

Positive Features

  • Walls can be installed to considerable depths
  • Walls with substantial thickness can be formed
  • The system is flexible in plan layout
  • The wall can easily be incorporated into the permanent works
  • The wall, or certain sections, can be designed to carry vertical load
  • Basement construction time can be reduced
  • Economical, positive solution for large, deep basements in saturated and unstable soil profiles
  • Noise levels limited to engine noise only
  • No vibration during installation

Under certain conditions diaphragm walls may be used as cantilever, braced or tie-back walls.  Diaphragm walls are necessary:

  • in very unstable soil profiles below the water-table where continuous support and watertight conditions are required to prevent mud flows, piping and erosion of the soils;
  • where construction time is important and the use of a diaphragm wall can shorten the programme;
  • in conditions where deeper than normal cantilever support may be required. These conditions could occur where the wall is to act only as a cantilever, or where a very deep initial excavation is required before the first braced or tie-back supports can be installed.