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Last week, the first 2 foundation tiles were placed on the bottom of the Scheur in the Port of Rotterdam. The foundation tiles form the temporary foundation for the Maasdeltatunnel, part of the A24 Blankenburg connection. Strukton Immersion Projects (SImP) is placing the foundation tiles on behalf of BAAK (a consortium of Ballast Nedam, DEME Group and Macquire).
As many as 12 foundation tiles will be installed for the two tunnel elements, which will be immersed in spring 2023. The foundation tiles weigh about 95 tonnes each and 4 foundation tiles have a size of 7 x 7 metres and 8 foundation tiles have a size of 6 x 6 metres. For placing the concrete foundation tiles, DEME and W. Smit BV, among others, are cooperating. After the foundation tiles are placed, divers will disconnect the lifting equipment at a depth of about 30 metres and then prepare to place the next foundation tile.
Tides and currents at this location make placing the foundation tiles extra challenging, but still manage to place the foundation tiles on the bottom within a few centimetres tolerance. GEOCON is used to determine the position of the tile. For this purpose, the system is duplicated. Both GPS and measuring prisms are used to determine the location and orientation.
SImP has extensive experience in placing the foundation tiles on the ground. Foundation tiles were previously placed by Strukton for the Limerick Tunnel and the North/South Line IJ Tunnel, for example. The gigantic concrete foundation tiles are laid with the accuracy of a few centimetres.
There is no subtitute for experience
Placing the foundation tiles on the bottom is one of many preparations for sinking the two tunnel elements of the Maasdeltatunnel. The two tunnel elements will be immersed in spring 2023. The Blankenburg connection will make it possible to drive from the A20 near Vlaardingen directly to the A15 in the Botlek.
The new North/South Metro line in Amsterdam is in operation since July 2017. The 9 km line runs from the northern ring road to the southern ring road and passes the historic and very vulnerable city centre. For the part in the city centre special tunnel techniques were applied to limit the impact on both the historic buildings and the disruption of city life.
One special technique that was used is the immersed tunnel technique. This technique has been used for the crossing of the IJ-river under very soft soil conditions and for the crossing of the historic Amsterdam Central Railway Station. The application of the immersed tunnel technique underneath a historic building has never been applied in the world and was a true challenge considering the special immersion trench that had to be created underneath the building. The tunnel was successfully immersed under the Central Station in the summer of 2011. This paper will focus on the technical challenges of the complicated underpass of the historic Central Railway Station and the IJ-river crossing.
The Busan Geoje Fixed Link project is one of the landmark projects in South Korea, providing a road connection between Gaduk and Geoje Island near to the city of Busan at the Southern tip of the Korean peninsula. The project consists of two Cable Stayed Bridges, an Immersed Tunnel, rock tunnels and it has a total length is over 8 km.
This paper will focus on the immersed tunnel part of the link and the particular challenges that the project faced in designing and constructing the tunnel, these challenges required a significant evaluation in immersed tunnel technology. The tunnel consists of 18 tunnel elements and has a total length of 3.6 km. The tunnel location was characterised by the following conditions:
Strukton Immersion Projects is participating in the international tunnel congress, the World Tunnel Congress 2022 in Copenhagen. From 2 to 8 September 2022, Strukton Immersion Projects can be found at stand E-49.
Strukton Immersion Projects has taken the initiative from the Working Group 11 (Immersed and Floating Tunnels) of the International Tunneling and Underground Space Association (ITA) to develop a stand together with partners for this exhibition that promotes the immersion of tunnels and caissons. We will be on this stand together with fellow companies that are also closely involved in the Working Group 11.
Strukton Immersion Projects recently floated out the tunnel elements of the Blankenburgverbinding and towed them out of the Keppel/Verolme construction dock. Strukton Immersion Projects will immerse these tunnel elements in March/April 2023. Strukton Immersion Projects is also working on the highway tunnel under the Schelde for the Oosterweelverbinding in Antwerp. This concerns the transport and immersion of 8 tunnel elements.
The new suspension bridge over the Çanakkale Strait (Dardanelles), a strait in north-western Türkiye, is an important part of the highway that will connect the cities of Çanakkale and Malkara (near the Greek border). The Turkish companies Limak and Yapi Merkezi, with SK E&C and Daelim from South Korea, are the Joint Venture responsible for it. The DSLY JV in turn commissioned specialists Strukton Immersion Projects to float out, transport and install the foundation structure: two gigantic caissons measuring 74m by 83m and 45m high. The installation of the caissons was successfully completed in May 2019.
The magazine E-mosty published an article about the work carried out by Strukton Immersion Projects. The complete five-page article can be found here.
The Rotterdam region is of great economic importance. Rijkswaterstaat has noticed that this region is coming under pressure from overcrowded roads. To guarantee accessibility, quality of life and economic activity in the future, a new connection is needed. The Blankenburgverbinding is a new freeway (A24) that will connect the A20 at Vlaardingen with the A15 at Rozenburg from 2024 onwards. Construction consortium BAAK (a combination of Ballast Nedam and DEME Infra) is constructing the Blankenburgverbinding on the constructions of Rijkswaterstaat. The contract includes the design, construction, 20 years of maintenance and the entire financing of approximately 1 billion Euros. With two junctions, a land tunnel and an immersed tunnel, the accessibility of the Rotterdam region will be improved, and a contribution will be made to the growth of the economy.
The Maasdeltatunnel forms the link between the north and south banks of the Blankenburgverbinding. Two tunnel elements will be immersed in the river Het Scheur at a depth of 28 meters below sea level. A tunnel with a story, a construction of Dutch Craftsmanship.
The biggest challenge within this project is the immersion of the two tunnel elements, which together form the Maasdeltatunnel.
In a dry dock, a stone’s throw from the construction site in Rozenburg, BAAK built two tunnel elements of approximately 200 meters long, 42 meters wide and 8 meters high. In order to make the tunnel elements watertight, Strukton Immersion Projects provided the four tunnel bulkheads. The modular steel bulkhead panels were placed in the openings with great precision. This precision is crucial because the smallest imperfections can lead to leaks.
After installing all mooring wires and winches, everything was carefully and extensively checked against checklists. A GO during the Go/No Go meeting was the signal to fill the construction dock with water. During the filling process, continuous checks were carried out in the tunnel elements and the tunnel elements were floated up in a controlled manner. With two tugboats the tunnel elements were transported to a temporary mooring location. The floating up and transport was carried out with precision and craftmanship by the team of specialists from Strukton Immersion Projects and DEME Infra.
The tunnel elements will remain at the temporary mooring location awaiting the immersion. In 2024 the final result will be a 924-meter tunnel for traffic between Rozenburg and Vlaardingen.
(Source: among others Rijkswaterstaat, Ballast Nedam, DEME Infra)