Exploratory cyclic and dynamic numerical investigation for the assessment of the seismic vulnerability of Blockhaus shear walls under in-plane lateral loads

The paper investigates the seismic response of Blockhaus shear walls under in-plane lateral loads. As known, the typical Blockhaus systems consists in a series of timber structural elements stacked horizontally once upon each other and interacting by means of traditional timber joints based on the effectiveness of carvings and contacts of multiple surfaces. Native of forested areas, Blockhaus systems are widely used in daily practice for the construction of wooden houses also in earthquake-prone regions. However, the seismic characterization of this construction system currently requires further investigations and studies. In order to assess the vulnerability of the examined structural typology, Finite-Element numerical investigation on log-haus timber walls subjected to in-plane lateral loads are performed by means of a computationally effective FE-model derived from earlier research contributions. In it, non-linear hysteretic springs implemented in ABAQUS/Standard and validated to cyclic experiments of single joints are used to describe the joint behaviour. Parametric cyclic investigations are first presented, in order to highlight the effects of multiple geometrical and mechanical aspects on the in-plane cyclic response of single log-walls. Refined non-linear dynamic analyses are then proposed for a significant set of configurations characterized by different geometrical properties and applied vertical loads, and preliminary estimations for the q-behaviour factor are presented.