Expansion and tensioning of WTC foundations

Due to the expansion and heightening of the WTC at the Zuidas in Amsterdam, the existing foundation had to be expanded. In addition to the existing pile foundation piles, new steel tubular piles were installed. From the parking garage on -2, all the pile foundation piles were excavated one by one. This brought the existing piles into view. Heavy steel beams, which were specially designed and assembled for this application, were installed under the existing foundations and laid on the new tubular piles. By tensioning flat jacks on the steel structure, the load from the existing concrete structure was partly transferred to the new foundations. Partly due to the combination with Rijnstaal, we carried out the UO engineering of the jack steel, the production and assembly of the steel and jack work as a complete package. The internal height of the parking garage on -2 and the phasing in the groundwork made for a challenging assembly.