Bologna new High Speed railway station extends underground along approximately 640m by a 56m width and a 25m depth.
The open-cut excavation to execute the underground station box was designed through an innovative structural system, which contemplates reinforced concrete diaphragm walls with unusual shape and static behaviour: the Vaults, diaphragm walls with an arched cross section absorbing thrust actions mainly by the compressive behaviour of the concrete, and the Buttresses, T-section diaphragm walls designed to react to actions transmitted by the Vaults by flexural behaviour. In order to ensure the stability of the excavation of such diaphragm elements, whose cross section area was about 10 square meters, a ground improvement around the perimeter of the excavation was provided through Cutter Soil Mixing technology.
An automatic geotechnical, structural and topographic monitoring system has allowed to detect the interaction between ground and structures during all construction phases and its impact on the adjacent urban context.
Subjects: Vault, Buttress, Cutter Soil Mixing
Author: Luca Utzeri, Stefano Ciufegni and Francesco Sacchi
Publisher: DFI, EFFC