S21 – Foundation

The Stuttgart 21 railway project requires a large number of structural changes in the state capital Stuttgart. These include the construction of a new eight-track through station. This new underground station consists of an approx. 447 m long and 80 m wide hall.

Jointless Solid Construction with Sophisticated Settlement Behaviour

The construction consists of a trough made of normal concrete and a seamless shell roof made of white concrete. The entire structure is designed as a jointless solid construction. Space joints are only found at the transitions to the north and south heads. The requirements for the solid construction are very high due to the WU construction of the trough.

Base Gypsum as Separation Layer to the Mineral Water Horizon

The trough consists of a base slab, which varies in thickness between approx. 1 m and 2.5 m according to the platform and track area geometry, and the adjoining side walls. The trough structure is founded on driven in-situ concrete piles; only in the area of an existing suburban railway tunnel does it span this as a bridge structure. The driven piles usually end well above the base gypsum. This serves as a separating layer to the deeper mineral water horizon.