HDD drilling through a gravel layer
The "Hemelbeekduiker" is a culvert which crosses the Julianakanaal in Limburg, The Netherlands. This culvert required replacement and therefore the pipelines, a 10" and a 4" pipeline, which were installed in the culvert also required to be replaced. Our client, PPS-Pipelines, chose to install these 2 pipelines as a bundle by means of an HDD.
The project had several challenges, one of which was that the pipelines had to cross the “Hemelbeek”, where the existence of a thick gravel layer could cause problems for the HDD. Without suitable measures, a stable borehole within a thick gravel is not possible. We stabilised the gravel layer with of jet grouting after which the HDD was executed with a 250t rig through the cemented gravel layer.
Some other specifications of the project:
• The work areas to the west of the canal are located in the basin of the Maas River. In the event of (extreme) high water, there could have been a delay during the execution.
• The pipelines are assembled on a site in the floodplains of the Maas.
• For the pull in operation, the pipelines were to be transported over a temporary bridge we had built and positioned correctly before we could start the pull in operation.
• On the other side, east of the canal, in the parking lot in front of Castle Elsloo, a smaller 45t HDD rig was used to pull in the pipes due to the limited available space.
• During the installation, the free space around the pipes was filled with drilling fluid to prevent water seepage along the drilled line in the event of high water.
• The entire project had to be completed by the end of June 2018 which provided a tight deadline during the execution.
Several disciplines within Visser & Smit Hanab (engineering department, pipeline department and drilling department) were involved during this project and the project was executed in close cooperation with the client.
Visser & Smit Hanab successfully executed the project within the limited time available.
Due to the challenging and complex nature of the project Visser & Smit Hanab is one of the nominees for the NSTT No Dig Award 2018.