Robustness of timber buildings

Abstract

Robustness can be defined as the insensitivity of a structure to initial damage, or its ability to avoid disproportionate consequences in adverse loading events. It can be thought of as the last line of defense of a structure against a disproportionate collapse. Current design standards and guidelines are commonly based on a semi-probabilistic safety format using partial factors to account for known uncertainties of the materials and common loading scenarios. Certain accidental loading, such as human error, malicious actions, degradation, and more are not accounted for in the calibration of the partial safety factors. To prevent disproportionate consequences in the case of accidental loading scenarios, robustness strategies are often used to limit damage in structures of high consequence classes.

With the increase in the volume and complexity of current timber structures, it is becoming increasingly important to ensure a minimum degree of robustness. Existing robustness provisions were developed for reinforced concrete and steel structures, which may be unsuitable or detrimental when directly applied to timber structures. As such, research on the robustness of timber structures and knowledge transfer to practicing engineers are essential to ensure a minimum degree of robustness of timber structures.

At ETH Zurich, various aspects on the robustness of timber buildings are being researched in collaboration with multiple industry and academic partner institutions. This includes
• quasi-static and dynamic experiments on single components and structural sub-assemblies,
• advanced numerical and analytical modelling of mechanisms involved in progressive collapse,
• quantification of robustness,
• investigation of design strategies,
• reliability analysis,
• and risk analysis.

Support

The work is kindly supported by:
1. SNSF Grant Nr. 219965 Preventing disproportionate collapse in tall timber buildings
2. SNSF Grant Nr. 220112 RelyConnect – Reliable and high-performance modern timber structures with modern connections
3. SNSF Grant Nr. 213364 Robustness of timber structures – Experimental characterization of progres-sive collapse scenarios
4. MainWood, a Joint Initiative co-financed by the ETH Board
5. Albert Lück-Stiftung grant Zuverlässigkeit und Robustheit von Holztragwerken