Finite element assessment of the seismic performance of three dimensional Blockhaus buildings

The paper investigates the structural response and vulnerability of Blockhaus buildings under seismic loads. The typical Blockhaus systems consists of a series of linear timber members stacked horizontally one upon another 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 or commercial buildings also in earthquake-prone regions. However, no design provisions are given in the Eurocode 8. In this work, a Finite-Element (FE) numerical investigation is performed on full three-dimensional Blockhaus timber buildings subjected to seismic loads. A computationally effective FE-model developed in a previous research is implemented in ABAQUS. In this model, a key role is played by nonlinear hysteretic springs used to schematize the cyclic behaviour of the joints between perpendicular linear members and validated on cyclic experiments of single joints. Nonlinear dynamic analyses are carried out for some building configurations of technical interest. Preliminary estimations of the corresponding q-behaviour factor are also presented.