GNGTS 2013 - Atti del 32° Convegno Nazionale

buildings. Experimental results obtained by cyclic and monotonic full-scale tests performed on three different typologies of Blockhaus shear walls are discussed (Fig. 1b). When shear walls are subjected to in-plane lateral loads, the adopted timber-timber connections ensure significant flexibility of the structural system and enable the attainment of large displacements. At the same time, it is well-known that the shear strength of Blockhaus walls subjected to seismic events totally depends on the number of intersections between the main wall and perpendicular walls, as well as on the geometry, thus on the resisting surfaces, of the adopted timber-timber connection detail (Figs. 1c, 1d, 1e). Experimental and numerical results discussed in the following sections highlight in fact that several factors can affect the seismic behavior of Blockhaus structural systems (e.g. the presence of possible geometrical imperfections in the timber carpentry joints, the contribution of friction phenomena, the mechanical properties of timber and the interaction between seismic lateral forces and vertical permanent loads). In any case, large flexibility and high seismic strength is generally found. Moreover, if appropriately calibrated, sophisticated numerical models are able to realistically reproduce the seismic response of Blockhaus systems under in-plane lateral loads. Full-scale seismic experiments. Firstly, six full-scale cyclic and monotonic seismic tests have been performed on three different typologies of Blockhaus shear walls, in order to assess their structural response under the effects of in-plane seismic loads. The typical specimen (Fig. 1b), currently produced by Rubner Haus (www.haus.rubner.com ), consists of a 2.95 m (height) 2.95 m (width) ‘Tirol’ wall made up of 18 basic components, that is 90 mm wide and 160 mm deep timber beams obtained by gluing together two 45 mm thick lamellas of C24 spruce (UNI EN338:2004). The transversal cross section of a ‘Tirol’ log is typically characterized by the presence of two 0.01 0.01 m notches, able to improve interlock and friction properties between top and bottom contact surfaces between overlapping logs. The main difference between the examined specimens is given by the joints adopted to constrain the main shear wall at its ends, consisting respectively in ‘Standard’ halved joints (S01, Fig. 1c), double ‘Rounded Dovetail’ hard wood shaped joints (S02, Fig. 1d) and ‘Tirolerschloss’ joints (S03, Fig. 1d). Fig. 1 – a) ‘Blockhaus’ building; b) typical ‘Blockhaus’ shear wall (measures in mm); c) ‘Standard’ carpentry joints; d) ‘Rounded Dovetail’ carpentry joints; e) ‘Tirolerschloss’ carpentry joints. 23 GNGTS 2013 S essione 2.1