STOCKHOLM BYPASS | PROJECT
Above: The large-scale tunnel excavations are mostly complete and the Bypass project will move to fit-out works important to the client to not have a visible presence
on the ground.” Challenges above ground as well as below. “That gave us some problems, as cut and cover was
ruled out,” Stille continues. “What we were able to do in some places was jet grouting: you inject the soil with grout under high pressure, using a rotational head, so that you break up the soil and it gets mixed with the cement slurry. “The muck was removed by conveyor, some to
barges, some to dumpers or lorries. What happened to it after that differed. The chemical composition of the rock mass was tested every hundred metres of tunnel. Depending on the result, some was used for landfill and some we could sell to a contractor who used it for roads and foundations.”
EXCAVATION NEARS COMPLETION Tunnelling excavation is mostly finished on Stockholm Bypass. In addition to his work in the design consultancy JV, Stille was also a Technical Director with Aecom Nordic AB. He finished his most active onsite engagement on the Bypass in 2022 but has remained engaged with the project as an adviser on some final aspects. His own consultancy (TriEng - short for Tunnel, Rock
and Infrastructure Engineering) also works on other projects. Projects glide into one another, he observes.
“I have been working on the new Stockholm
metro, and on a repository for low- to middle-grade radioactive material. We are excavating large caverns for them in the middle part of Sweden.” On Stockholm Bypass, the focus of work is turning to
fit-out. He says: “The installations and fitting out have still
to be done – that is everything from the water and sprinkler systems for fire protection, and ventilation, and electrics – there will be a lot of electrical signalling involved, traffic lights and so on. There are emergency cross-passage about every 100
metres along the tunnels, and these will have huge numbers of detectors in them, for smoke or water-leaks and so on. “We will put more inner linings in, not for stability but
for the sake of the drivers who use it,” he says, as 17km is a long way to drive. “It improves the experience and safety if you can orientate yourself with some kind of variety as you progress. So it will not all be naked rock or shotcrete. “For the same reason, the cross-passages are all
marked with names as well as numbers,” he says. “It will give you some idea of where you are in relation to the surface above you.” Stockholm Bypass is due to be fully operational in
2030. One part, the stretch between Häggvik-Hjulsta, could be open in 2026.
April 2025 | 21
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43
