Buckling of Blockhaus walls under in-plane vertical loads

Blockhaus structural systems are commonly obtained by assembling together multiple timber logs. Although based on simple mechanisms of ancient origins, the structural behavior of Blockhaus systems under well-defined loading and boundary conditions is complex to predict. The paper focuses on the assessment of the typical buckling behavior and resistance of vertically compressed timber-log walls. The effects of various mechanical and geometrical variables such as possible geometrical imperfections, openings (e.g. doors or windows), fully flexible or in-plane rigid inter-storey floors are investigated by means of advanced finite-element numerical models able to properly describe the effective interaction between multiple overlapping timber logs. Comparisons with analytical solutions are also presented and critically discussed, in order to assess the applicability of existing formulations to Blockhaus structural systems.