A high degree of transparency: Fully glazed gridshell with innovative node solution

An atrium roof with patented node solution for a research building suffused with light in Basel – planned by formTL Ingenieure and realised by RUCH Metallbau

In the immediate vicinity of the University Hospital of Basel, a new laboratory and research building has been completed for ETH Zurich on its Schällimätteli campus. The D-BSSE (Department for Biosystems Science and Engineering) atrium building is characterised by a formal clarity and spatial permeability – for Nickl & Partner Architekten also wished to mirror the interdisciplinary academic exchange in the architectural design. A high degree of transparency marks its appearance from the outside.

At the centre of this fully glazed five-storey building, the architects also placed a light-suffused atrium intended to encourage communication between the teams of researchers with its great welcoming quality. The inner courtyard’s floor plan forms an irregular triangular shape above which it is spanned by a glazed, graphic-like gridshell. It protects the atrium against wind and weather while giving the space an atmospheric ambience. The workshop design of this innovative meshed support structure was undertaken by formTL’s engineers– in close collaboration with the executing metal construction company RUCH Metallbau AG from Altdorf.

The vaulted, unsupported glass roof structure consists of a single-layer dome shell which is approximately 20 metres in width and 35 metres in length. Its glazing bars made of hollow steel sections intersect in such a way that triangular lattice meshes are created. This structural principle gives the glazed roof covering its characteristic look. The base of the glass roof is formed by a border beam made from steel tubes which follows a free form in the planview. The individual prefabricated components of the grid structure are assembled and welded onto this.

The core of the gridshell is a particular node developed by formTL and RUCH Metallbau specifically for the project. This patented front surface node construction made it possible to optimize the entire manufacturing and assembly process and for the atrium roof, to be built without any secondary structure for the glazing. Proof of the residual load capacity of the broken glass of 60 hours was demonstrated with a mock-up at a scale of 1:1.

formTL took charge of the 3D-model and geometry for the atrium roof covering, workshop and assembly drawings as well as the static verification. This ensured that the data flow was continuously from the draft to the CNC plant in the workshop. Thanks to the optimally coordinated work processes, the new atrium roof for the Basel research building could be planned precisely and realised in high quality in teamwork between formTL and RUCH Metallbau.

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Article courtesy of formTL