Robustness of Multi-Storey Timber Buildings

This paper investigates the probability of disproportionate collapse for a nine-storey mass-timber building designed for gravity and lateral loads. This is a static analysis which accounts for both geometric and material nonlinearities. Considering 32 different scenarios, the proposed building is subjected to removal of ground floor columns, one or two at a time, to compute the reliability index. As limit state functions, the results take into account the residual capacity of the building, in terms of bending moment resistance and shear stress within Cross-laminated timber panels, as well as the resulting deformations. Results indicate that failure is dictated by the imposed deflections rather than the capacity of the timber elements. The investigation shows that the proposed building does not have sufficient robustness to redistribute the load to the undamaged part of the building after the considered removal scenarios.