The reception building (Aufnahmegebäude, AG) was built in 1913 and represents the station building of the St. Gallen railroad station. In the course of time, the building was repurposed several times.
The floor plan of the building has dimensions of 123 x 22 m and is divided into a west and an east wing. The east wing has a basement, a 9.6 m high ground floor of the station hall, 3 upper floors and a roof structure with another 3 upper floors. The west wing has a basement, a ground floor with gallery and mezzanine, 2 upper floors and 2 more floors in the roof structure. The entire basement was built in unreinforced rammed concrete. From the ground floor onwards, the walls are constructed in masonry made of bricks as well as sandstones along the facade. The existing columns are assumed to be rammed concrete throughout the whole building. The ceilings are ribbed ceilings of reinforced concrete with joists. The roof construction was designed entirely as wood structure with board floors. Round spruce piles were used for the foundation of the reception building.
As part of the redesign of the St. Gallen train station and station square, the basement and ground floor were converted. This required many complex interception structures for new or larger breakthroughs. Furthermore, a new gallery floor was built in the east wing in timber construction and accessed with a steel staircase. To transfer higher loads or new point loads, the ribbed ceiling had to be reinforced in many places.
To ensure earthquake resistance, six new reinforced concrete walls, which are founded with micropiles, were installed in the building during operation. Due to the drop in the groundwater table since the building was constructed, not all of the timber pile areas are permanently below the water table, raising questions about their durability. Due to this, a material-technological condition survey and assessment of the timber pile foundation including the establishment of a monitoring concept was carried out.
In the case of the service building (Dienstgebäude, DG), which was built in 1956/57 and topped up by two floors around 1996/97, only minor interventions were carried out for earthquake retrofitting and the conversion of the ground floor. For the conversion of the ground floor area, mainly the eastern entrance area was structurally adapted. An existing ramp was replaced by a completely new ramp and staircase and the canopy above was reinforced.