Blockhaus structural systems are commonly obtained by assembling multiple timber logs, which are stacked horizontally on the top of one another. Although based on simple resisting mechanisms, the structural behaviour of Blockhaus systems is rather complex to predict, and few design recommendations are available in current standards for timber structures. In this context, the paper focuses on the assessment of the typical buckling behaviour of vertically compressed timber log-walls. The effects of various mechanical and geometrical variables such as possible load eccentricities and/or initial curvatures, openings (e.g. doors or windows), fully flexible or in-plane rigid inter-storey floors are investigated by means of detailed finite-element (FE) numerical models validated on buckling test results available in literature (Heimeshoff and Kneidl 1992; Bedon et al. 2015). By taking into account a wide set of geometrical configurations of practical interest, the effects of the main input parameters on the observed compressive buckling responses are first highlighted. In order to provide buckling design recommendations of practical use, normalized design curves derived from standards (e.g. the buckling design approach provided in the Eurocode 5 for timber members in compression) are calibrated and validated for log-wall assemblies.
