Brief characteristics of laying pipes using of narrow-trench methods

Brief characteristics of laying pipes using of narrow-trench methods

Brief characteristics of laying RC MULTIsafe® and RC MAXIprotect® PP/PE pipes using of narrow-trench methods.

Ploughing
Briefly, that method consists in lying of the pipe section on the bottom of the furrow made with use of the ploughing machine. In the beginning and end of each section the narrow excavations are made. After positioning the ploughing machine above the excavation the pipe and the warning tape, are pulled through the separated channels (tape at the specify high above the pipe) in the box connected with the plough share. After lowering the plough share to required depth the beginning of pipe and tape is anchored in the ground. Therefore during the ploughing machine movement the successive metres of pipe and tape are pulled from the ground level into the entry of the box connected with the plough share and then exit in the bottom of the furrow, where they are covered with soil spread with the plough share.

That method allows for:

  • pulling the pipes directly into the ground,
  • installation on depth up to 2 m,
  • high stability of pipe installation direction and depth thanks to plough height adjustment,
  • simultaneous installation of pipe and warning tape above it,
  • installation of pipes in the inclined areas, as well as in soils with high ground water level
  • low costs and high speed of pipeline installation.

Milling
That method consists in making a trench of width slightly bigger than the diameter of installed pipe using the milling excavator. The individual pipe lengths are welded on the surface and lowered as a whole to the excavation directly after the milling element, just like after the plough share in the ploughing method. Then the pipeline is covered with disintegrated native soil.

Requirements for pipes installation in native soil without sand bed and pack:

  • The native material from excavation of unspecified graining may be used again.
  • The soil used for pipe pack should not cause hollow spaces or holes. The material from the excavation should assure obtaining the required standard of compaction (Proctor factor), depending on designed load.
  • Pay attention that there are not stones in the soil used for filling which may cause pipeline damage (it is assumed that the maximum size is approx. 60 mm of diameter).
  • The excavation bottom should assure uniform support on the whole length, allowing for correct installation and obtaining the appropriate inclination.
  • Do not use waste material (e.g. rubble, scrap metal, etc.). In case of installing pipes made of PE100 RC during winter weather the pipeline should be covered with not frozen soil.