GIONGO, IVAN1; DIZHUR, DMYTRO2; TOMASI, ROBERTO3; INGHAM, JASON4;

1) Research Fellow, University of Trento (Italy), Department of Civil, Environmental and Mechanical Engineering, ivan.giongo@ing.unitn.it

2) Research Fellow, University of Auckland (New Zealand), Department of Civil and Environmental Engineering, ddiz001@aucklanduni.ac.nz

3) Assistant Professor, University of Trento (Italy), Department of Civil, Environmental and Mechanical Engineering, roberto.tomasi@ing.unitn.it

4) Professor, University of Auckland (New Zealand), Department of Civil and Environmental Engineering, j.ingham@auckland.ac.nz

Adequate performance of the shear transferring connection system between horizontal diaphragms and vertical structural wall elements is fundamental to the seismic response of unreinforced masonry (URM) buildings. When these connections are adequate, the building exhibits a “box” like behaviour and loads from end walls are transmitted into the in-plane loaded walls.

A field experimental campaign was undertaken with the aim to study the effectiveness of adhesive connection anchors to transfer seismic shear action from the timber diaphragm to the resisting URM walls, with the results reported herein. A total of 22 cyclic shear tests with varying parameters were conducted. The studied parameters included: the anchor rod diameter, the embedment depth, the timber blocking thickness, the boundary conditions, the washer size and the axial pre-load of the anchor. Subsequently to the shear tests, direct tension pull-out tests were also performed on selective anchors in order to define a simplified failure surface and residual anchor pull-out capacity.

An analytical formulation that was based on the Johansen Theory was used to evaluate the shear strength of the connection and the failure mode. The preliminary stiffness characterisation of the wall-to-diaphragm shear transferring connection is also addressed.

Keywords: Timber diaphragms, wall-to-diaphragm connection, clay brick URM, shear transferring connections.