Complex foundation under inner-city expansion

Vibration-free screw injection piles through special casings

Aurora Amsterdam is located at a crossroads of city districts, has a monumental facade and an existing basement. The new extension required a completely vibration-free foundation, performed in an extremely limited workspace and right in the heart of the city. A job for Ras Heiwerken.

Aurora's construction site is located on what Klaas Ras calls a lifeline of Amsterdam. “This is one of the busiest traffic points in the city. You have to deal here with limited space, few storage facilities and continuous traffic around you.” That makes foundation work extra sensitive. Low-vibration piling with tubular steel piles was not an option. “Because you're really downtown, that's out of the question,” he said.”

Vibration-free with compact drilling racks

For Aurora, Ras Heiwerken chose screw injection piles, installed vibration-free with compact drilling rigs. “Because of the groundwater level, these types of piles are the best option for this job. They are also the most durable. You can apply them with small machines, which require little fuel and produce emissions, and still be heavy enough to get those heavy piles into the ground.”

New foundation in an existing basement

A special part of the project was that the expansion is being built on top of an existing basement. “We were on the ground floor, but most of the property already had a basement. We made and assembled casings for that and placed them in the basement. Then we installed piles from above through those casings.” That was necessary to prevent flooding. “If you drill a hole there without casing, the basement would flood.”

The casings were custom-made specifically for this project in Breed's own factory. “That's one of our specialties. We made them ourselves, installed them and took them down when we were finished.”

Preparation almost as important as execution

According to Ras, the biggest challenge was in those casings. “That required good preparation. That was almost as important here as the execution.” The coordination with Van Wijnen and the structural engineer played a major role in this. “We consulted well in advance and together figured out how to do this safely and accurately.”

Despite the complexity, Ras looks back on the work with pleasure. “It's projects like this that keep it fun. A little challenge, at a location like that, that's what makes it exciting. And building downtown in limited spaces, that's just what we like to do.”