Sea Outfall Saint-Jean-Cap-Ferrat realized under limited space conditions
Oct 18, 2007
The modernization of the sewage system of Saint-Jean-Cap-Ferrat (Côte d’Azur) in France included the installation of a 110m long Sea Outfall pipeline. The construction company RPS mastered the narrow access routes, limited space conditions and unstable geology using a mobile Herrenknecht Crawler Rig HK150C.
At the “Pointe de la Causinière“, the seafloor is covered with corals. For environmental reasons, the cuttings therefore could not be removed with bentonite. Instead, they were ejected with compressed air. The geology – first, brittle and porous folded rock consisting of clay and limestone, and then weathered rock and sand formations – represented a challenge for both the contractor RPS and the drilling technology. The first 10 meters of the bore were lined with concrete to avoid settlement and make cuttings removal with compressed air more efficient.
The planned pipeline alignment with a steep entry angle of 22 degrees could be handled without problems by the Herrenknecht rig and the jobsite installation that had been specially adapted. In HDD drilling, the drill bits are changed after pilot bore to expand the drill hole to its final diameter. A tricone drill bit (Ø 200 mm) was exchanged with a hole opener (Ø 864 mm), a hard rock drill bit, to expand the pilot hole at a depth of 36 meters below sea level. The disassembled drill bit then floated to the surface with an airlift bag. The hole opener was lowered into the sea in the same way, where divers connected it to the drill string. The Herrenknecht Crawler Rig HK150C with a thrust and pullback force of 150t then expanded the 110m long drill hole to its final diameter of 864mm. After pullback of the product pipe, the construction works were completed on July 4th, 2007. A challenging Sea Outfall project, characterized by limited space conditions, a steep entry angle, and unstable geology, was successfully completed by the construction team using the flexible and efficient Herrenknecht Crawler Rig.
Head of Corporate Communications
Phone: +49 (0) 7824 302-540
Fax: +49 (0) 7824 302-473
More News and Articles
Feb 19, 2024
Our panel of international experts examines how utilities can embrace a global outlook when it comes to security.
Feb 16, 2024
The Silver Creek Water Corporation in southern Indiana manages millions of gallons of water, over hilly terrain, for 20,000 people. Over several decades, the utility has deployed technology from Xylem’s Sensus brand to remotely manage meters, prevent water loss and …
Feb 14, 2024
As the underground grows more crowded, the industry is under pressure to deliver highly accurate installations through a web of existing infrastructure.
Feb 12, 2024
In a new study, scientists at Heriot-Watt University have discovered a sustainable method to produce green hydrogen, a type of renewable fuel, using wastewater from the distilling industry. This new approach not only addresses the global challenge of water scarcity …
Feb 09, 2024
The UK water sector should give more focus to the themes of delivering resilient infrastructure systems and protecting and enhancing natural systems, according to a survey about the UK 2050 Water Innovation Strategy.
Feb 07, 2024
Drinking water scarcity is a global issue, including in Sweden, where it’s also used for crop irrigation and various industrial operations. This practice is neither sustainable nor efficient. Hence, MDU has launched an innovative research project aimed at developing efficient …
Feb 05, 2024
Industrial companies and commercial building owners wanting to reduce waste to improve cost efficiency and save water, must become smarter in their operations, writes Paul Hartley, chief commercial officer, Ovarro
Feb 02, 2024
New online training course in the renovation section of the e-learning platform: Lining with Cured-In-Place Pipes (CIPP). The flexible remote seminar comprises units about basics, proceudures, installation of UV CIPP, final work, and spirally-wound lining. One section was developed with …
Feb 02, 2024
The Watercare network investigation team are currently assessing wastewater pipes in Auckland suburb Mangere East, New Zealand.
Jan 31, 2024
Tunnel boring machines Daphne and Beatrice are preparing to relaunch at the Sydney Metro West site at The Bays, New South Wales.
Jan 29, 2024
Groundwater is a keystone ecosystem. An international study proposes ways to improve its protection to preserve biodiversity and mitigate climate change.
Jan 25, 2024
Digital water technologies have the potential to create resilient water utilities capable of responding to unpredictable weather patterns, says Adam Wood, chief product officer, InfoTiles.