New timber construction system using wood connections

The new Vidy theatre pavilion (Lausanne, Switzerland) is an architectural and engineering landmark that has sent the construction world dazzling at its marvel. Such awe can be attributed to the fact that it is the first structure to incorporate entirely the application of a full-scale double-layered timber folded-plate structure. This is an interesting implementation of knowledge gained from the laboratory research in creating eye-catching structures. Previously, it was deemed impossible to erect such a structure using the wood-wood connection. However, since the onset of this decade, researchers in the Laboratory for Timber Constructions (IBOIS) at the Swiss Federal Institute of Technology in Lausanne have persistently toiled and moiled in a bid to crack the precedent shortcomings that blockaded the application of such joints. Furthermore, it was necessary to unravel the mystery encapsulating the mechanical characterization of the Vidy pavilion connections in rotation for it to be a successful project.

Therefore, a team of researchers took on this challenge: Julien Gamerro, Christopher Robeller, and Professor Yves Weinand assessed the structural design of the innovative wood-wood connection designed for the full-scale double-layered timber folded-plate structure: the Vidy theatre pavilion. In addition, the purposed to help the Weinand Design Office to understand the rotational behavior of such connections for the real project. Their work is currently published in the research journal, Construction and Building Materials.

They commenced their study by analyzing the rotational behavior of the wood-wood connections in two parts: one focusing on single-layered joint and the other on the double-layered one. Next, they undertook a comparison of the differently engineered wood products. Lastly, the Single and double-layered connections are tested for a real project on whether they could adequately resist the maximum moment generated by the loadings within the structure.

The authors observed that the Cross-Laminated Timber panel with five layers of 9-mm thickness showed strong qualities for rotational applications even when other characteristics were taken into account. The three researchers also noted that the double-layered joint displayed high rigidity for the failure mode in bending in the reduced section. This was seen as a good compromise between the number of joints, the joint length, and the length of the reduced section in order to obtain a good structural integrity irrespective of the different stresses acting on the structure.

The study showed that Vidy theatre pavilion is the first large-scale double layered folded plate timber structure. This design has been implemented based on the results of the various researches performed at IBOIS Swiss Federal Institute of Technology in Lausanne. More so, the connections utilized here are an integral part of the structural timber panels, and this was made possible by the automatic generation of the building components. Altogether, the work has helped to comprehend and assist the structural design office for rotational solicitation of the real project by allying tests and calculation models.