I can find https://www.berlin.de/en/news/8097068-5559700-stabilization-work-u2-tunnel-alex-friday.en.html https://www.berlin.de/en/news/8097068-5559700-stabiliz

I can find https://www.berlin.de/en/news/8097068-5559700-stabilization-work-u2-tunnel-alex-friday.en.html https://www.berlin.de/en/news/8097068-5559700-stabilization-... Which states that due to sandy soil concrete was injected with lances. It was done by a French company. Might be the same tunnel?