“Experimental and numerical investigation of “Blockhaus” shear walls under in-plane cyclic loads.”

Blockhaus systems represent a traditional construction technology where structural resistance is obtained by direct contact between multiple timber surfaces obtained via carvings, notches, and ancient joints. Native of forested areas, this technology is currently used for the construction of log buildings also in earthquake-prone areas. Their seismic structural behaviour hence represents an interesting and not well-known research topic. In the paper, experimental results obtained by cyclic and monotonic tests recently performed on three different typologies of Blockhaus shear walls are presented and discussed. At the same time, sophisticated finite-element numerical models able to take into account the complex structural behaviour of log-walls subjected to in-plane seismic forces are described. Performed numerical simulations highlighted that in general multiple factors affect the global structural response of Blockhaus shear walls, including the presence of imperfections (small gaps) in the used timber joints, the contribution of friction phenomena, the mechanical properties of timber and the interaction between in-plane seismic forces and vertical permanent loads.