Aerated Concrete

Filling Pipe-in-Pipe system|Secondary lining method on shield tunnel and mountain tunnel

Shield Secondary Lining

In a shield tunnel or a mountain tunnel, secondary lining of newly-built pipes is executed using Aerated mortar to prevent ground settlement and deformation of buried pipes. Also, pipelines are filled with Aerated mortar in order to stabilize and protect pipes. Aerated mortar is adopted for various pipes installation due to its excellent features such as lightweight, fluidity, cost effect and long-distance pumping.

Features of Shield Secondary Lining
  • Lightweight feature and fluidity enable long-distance pumping.
  • High filling rate can meet wide range of clearance.
  • Shortened construction period because of its efficient work condition.
  • Economically efficient.
FRPM Pipe Method(shield second lining)
  • Filling of water supply and sewage pipes.
  • Filling of gas pipes.
  • Filling of pipes in a mountain tunnel.
  • Filling of FRPM pipe (FRPM Pipe Method).

FRPM Pipe Method(shield second lining)

FW pipe, which is the reinforced plastic composite pipe i.e. FRPM pipe utilized in sewer on sewerage secondary lining site, is carried and installed in the segment, and grouting agent (Aerated mortar) is injected into the gap between the pipe and the segment in the secondary lining. It is lightweight, is easy to handle, enables shorter work period, and has high durability. After the lining works, prevention works for water leakage and other maintenance works are not necessary. Inner surface of FRPM pipe is smooth having low roughness coefficient (concrete: 0.013, FRPM pipe: 0.01) that enables its inner diameter of 10% less than the secondary lining of concrete, it delivers an economical way and high level of safety.

Features of FRPM Pipe Method
  • Enhanced performance of inner/outer water pressure.
  • Enhanced antiseismic performance.
  • Higher chemical/acid resistance.
  • Reduction of drilled sectional area.
  • Shortened construction period.
  • Respond to multifunctional sectional area.
Application of FRPM Pipe Method
  • Shield secondary lining of sewerage works.
    Especially, under severe conditions such as limited routes or cross-section and a work needs corrosion resistance.

Example of Construction

Filling of pipes – Shield secodary lining (Water supply and sewage system)
Filling of pipes – Secondary lining method on mountain tunnel
Filling of pipes – Shield secodary lining (Gas pipe)
Filling of pipes – Shield secodary lining (FRPM pipe)

Major Achievements / Construction type and application ▶

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