Collective construction control
On the occasion of our lunch colloquium today, we went on an excursion to our favourite area in Zurich. With the completed Guggachpark behind us, flanked by the construction site for the new housing development, we were explicitly interested in the new school building Guggach III. In the meantime, the shell of the building has grown out of the ground and the imposing supporting structure of the three-storey underground gymnasium has been completed.
The two engineers in charge of the project, Andrea Bassetti and Gabriel Belser, vividly explained the challenges and concepts of the excavation and structural design to the assembled office team.
The geometric situation required the realisation of vertical excavation pit closures for the construction of the approx. 10.7m deep excavation pit. For this, three-layer back-anchored retaining wall beams with a concrete infill were used.
With the composure of a retrospective, Andrea Bassetti also addressed the particular “sticking points” of the civil engineering planning: the superstructure of the railway tunnel that crosses the construction perimeter, dealing with the high groundwater level and the sometimes very cramped anchoring conditions.
Gabriel Belser then presented the supporting structure of the school building, which is characterised by a high proportion of prefabrication, and focused on the construction of the already completed gymnasium. Here, prefabricated prestressed concrete girders – laid in the transverse direction of the hall – with spans of 24m take the vertical loads of the light supporting structure of the three upper floors and transfer them to load-bearing walls. The maximum flexibility of the floor plan layout is ensured by using a minimum number of vertical load-bearing elements. The stability of the building against horizontal actions is mainly ensured by two eccentrically arranged stair and lift cores.
