The large Groningen Ring tunnel is already waiting for September traffic, but it cannot enter yet

Since Monday, road users have been driving happily across the Julianaplein in Groningen from Assen (A28) to Drachten (A7/N7), through the first new connecting tunnel at the junction.

The ring road is now closed on the east side of Julianaplein until September 2. Yet in some places you can see that the northern track of the large tunnel on that side of the road, the Deepened Location, is already ready. Why can’t we get through that until September?

Spokesman Bert Kramer of ring road builder Combinatie Herepoort quickly has the answer: the tunnel is not yet finished. In fact: You can’t even enter that north lane. “On both sides of the tunnel we still have to connect the asphalt to the adjacent road sections: Europaplein and Julianaplein. In addition, the tunnel can only open when all systems are complete and working properly. We will be busy with that in the coming period.”

It’s done, it’s done

Under the motto It’s done, it’s done Herepoort has already completed the first part of the tunnel, the north track. Road users will soon drive there on the A7/N7 from east to west: from the Euvelgunne and Europapark junctions to Julianaplein and further towards Drachten or Assen (A28).

Fences stop work traffic, the top layer is in place and the four lanes have clear lines. Those who are lucky and can go on an excursion will bounce along on the soft top layer of very open asphalt concrete that also lies on the floor of this tunnel.

The lighting is on (many lights where you enter the three tunnels, fewer near the exit), there are green emergency doors between the north and west lanes and the emergency stairs are accessible.

Polder construction protects tunnel against water

“We are further completing the polder constructions around both entrances. These ensure that no groundwater can flow into the tunnel,” Kramer explains.

This is quite a job, especially on the east side, near Europaplein, because the temporary ring road, which traffic has used in recent years, was located in the middle of the polder area.

“Before we can install the last part of the sheet pile wall of the Deepened Location, the temporary road must be moved aside. Fortunately, we were able to start doing this during the May holidays when traffic in one direction was blocked,” says Kramer.

Because of this temporary road, the constructed access road to the tunnel does not yet have the full width. Kramer: “As soon as the final sheet pile wall is in the ground, we can dig and add a final strip to the concrete floor. We then hoist concrete walls into place, which, due to the speed, have already been partly pre-built and finished with brick strips. We will build the rest of the walls against that.”

Enter the tunnel

Once the walls have been poured and the ‘foil polder’ on the east side is ready, groundwater can no longer flow into the tunnel and Herepoort can extend the ring road from the viaduct above the Europaweg. “We are also moving the driveway from Europaweg. You always went up there to Julianaplein. Soon you will dive into the tunnel.”

On the west side of the Verdieping Ligging, at De Papiermolen, the ‘polder’ is technically somewhat easier to build. A sheet pile wall will also be installed at the final location, but no concrete work is required at this location.

In the meantime, ring road builders are completing the other southern ‘tunnel tube’. This will also be used in the near future by the many trucks carrying demolition material from the temporary ring road. The sand goes to the Sugar Side.

Temporary road disappears this summer

Kramer: “We will basically completely demolish the temporary road this year. Most of it will be gone by September. Part of the viaduct above the Hereweg will remain in place until the 4Mijl (October 13). We will then remove that too and the Hereweg will be overhauled until the end of December. When this redesign is complete, the Máximaweg, the new connecting road between Hereweg and Brailleweg, will also open.”

Before removing the viaduct above the track, Herepoort must wait for the train-free period from August 3 to 12. There will be no trains running between Main Station and Groningen Europapark. The ring road builders are conjuring up an important cycling part of the Ring South Approach: the Esperanto tunnel.

The part of the bicycle tunnel under the railway has been there for years, but the bicycle (supply) paths have not yet been constructed because the temporary ring road was at that location. After the summer, Herepoort will start these cycle routes to the tunnel on both sides of the railway. This ‘cycling valley’ will be ready in May 2025.

Herepoort does not yet have the demolition of a small section of the original ring road viaduct at the Meeuwerderweg on the agenda, Kramer confirms. It would remain on the ring road as a reminder of the project Memory Pavilion . Local residents protested at the municipality. Kramer: “If it has to go, we will hear about it.”

Lots of testing before opening

Even once both tunnel tubes have been set up, a lot still needs to be done, says Kramer. “There is a lot of technology in and around the Verdieping Ligging. For example, there is no emergency lane, but a detection system that ‘sees’, for example, when a car is stationary. It will automatically ‘cross’ lanes and allow the Rijkswaterstaat traffic control center in Wolfheze (Gelderland, ed.) to monitor to determine what else needs to be done,” says Kramer.

In the event of a serious incident, a tunnel tube closes. Occupants can then exit via the stairwells or emergency doors to the other tunnel tube. From there, emergency services can reach the incident. There will be an emergency passage on either side of the tunnel for emergency services and traffic that may have to turn around.

Kramer: “There is a dry fire extinguishing water pipe in the tunnel for the fire brigade. There is normally no water in there. They can quickly pump it in from 2 filling points. Before the tunnel opens and has been thoroughly tested, the fire brigade, ambulance service, Rijkswaterstaat and police will also practice so that everyone knows what the tunnel looks like and knows the safety procedures.”

Approach Ring South calls the tunnel a Sunken Location because the three covered road sections are shorter than 250 meters. As a result, they are not legally tunnels and the Sunken Location does not have to meet the requirements of tunnel legislation. As a result, for example, there are no fans and there is no central escape tunnel.