Multiple materials and mixed installation method
To cross an existing highway, two parallel horizontal directional drillings (HDD’s) will be made, using polyethylene pipes. Beside the highway, these pipes will be connected to a nodular cast iron pipe. The two separate pipelines will join, using a Y-joint.
Key features of this project are:
- Method of installation: Partially conventional trench, plus two seperately drilled HDD’s with a length of 235 meter and maximum depth of 23 meter.
- Pipe dimensions (D x t): 842 mm x 11.7 mm, 1048 mm x 13.5 mm and 800 mm x 72.7 mm
- Pipe material: nodular cast iron and PE100 polyethylene.
- Important loads: internal pressure: 5 barg, soil subsidence: 58 mm, soil pressure, pulling forces and traffic loads.
Analyses were done to ensure all parts of the pipeline were meeting the Dutch pipeline code NEN 3650-2:2012 requirements.