Amstel Stream bridge will be an ecological masterpiece

It can safely be called a special design. The bridge that the City of Amsterdam is having realized over the Duivendrecht canal will contribute to the city's ecological network. The design comes from Mobilis B.V. and VenhoevenCS Architecture & Urbanism, with ecological input from consultancy firm Smartland.

GWW is in conversation with project managers Arno Bolder (Mobilis) and Edwin Abbink (municipality of Amsterdam) about the green design and the role the bridge will play in connecting Amstelkwartier with Joan Muyskenweg, for pedestrians, cyclists and vehicular traffic.

One step beyond the requirements

"In the call for tenders, there were requirements for design, maintainability and ecology," Edwin opens the conversation. "The bridge had to provide not only an infrastructural connection, but also an ecological connection to the environment and contribute to biodiversity." Mobilis and VenhoevenCS Architecture & Urbanism won the tender. Arno explains, "We went a step further than the municipality asked. That also suits Mobilis; we have years of experience with ecoducts and fauna passages. We simply understood the tender well, which was a matter of 'coming home' for us. By involving ecological consultancy Smartland in the design, we were able to respond very accurately to local ecology. Mobilis B.V. is realizing the project together with regular partner Van Gelder B.V."

The result will be a bridge that contributes to the ecological network, with a flower-filled median strip, with nest boxes for house and barn swallows in the bridge beams, with maternity chambers for bats in the center piers and nests for kingfishers and bank swallows in the side piers. "Extraordinary to be able to contribute to biodiversity in urban areas like this," Edwin suggests. "There will also be facilities in the bridge for plants and animals that have become relatively rare in the inner city, in the form of shelter, nesting and sleeping facilities for bats, birds, fish, bees and bumblebees. In that respect, Mobilis and VenhoevenCS Architecture & Urbanism have gone beyond the call for tenders."

A world unto itself

Ecologically, the bridge over the Duivendrechtsevaart will be a world unto itself, considering all the facilities for promoting and maintaining biodiversity. "There is also a lot of consideration for greenery," Arno continues. "The green median strip of Amstelstroomlaan will be extended across the bridge, including its own water buffer. Openings in the bridge deck provide daylighting under the bridge deck."

Durable design

Concrete was specifically chosen by TBI company Mobilis for the construction of the bridge. Arno explains: "That means less maintenance is needed, no painting, for example. In the design, the water piers have been placed in such a way that there is no need for bracing. That also makes a huge difference in maintenance costs." Edwin responds, "In that respect, too, the offer from Mobilis and VenhoevenCS Architecture & Urbanism was distinctive. Furthermore, the combination took into account possible changes in the future. Above the quays, the central reservation is open, but in such a way that a third lane can be realized later, if necessary. All in all, the tender, based on D&C, was quite abstract and quite special for the municipality."

The digital construction shop

At the time of the interview, the combination is working on the foundation for the water piers and the pile foundation for the abutment on the east side and setting up the construction site. "You know what's special?" asks Arno. "We had our 7th construction meeting yesterday, online of course. I've never physically spoken to the client team members before. We are literally sitting together in a digital construction shack..." Edwin adds in conclusion, "What's even more special? That even though we miss the live contacts, there is still a very close and pleasant collaboration. Quite unique, I think both teams are strong in their communication."