r+k Consulting Engineers

HDD using joined cast-iron pipe segments

A potable-water pipeline has to cross a waterway. This is done by using horizontal directional drilling (HDD) of a nodular cast iron pipeline, using 59 pipes, each with a length of 6 meter and connected with tensile resistant socket-spigot connections.

Key features of this project are:

  • Method of installation: HDD with a length of 350 meter and maximum depth of 15.6 meter.
  • Pipe dimensions (D x t): 945 mm x 12.6 mm.
  • Pipe material: nodular cast iron.
  • Important loads: internal pressure: 6 barg, soil pressure, pulling forces.

A pipeline / soil model was made and calculations were done to see if the pipeline design is according to the Dutch NEN 3650 code. Another calculation was done to check if the pulling force wouldn’t exceed the maximum allowable force.

Cast iron HDD

HDD using cast iron pipes, locations of the joints are indicated

The results showed that the design criteria were met.

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