This paper presents the results of the LNEC-3D shaking table tests on two mock-ups, Brick House and Stone House, carried out in the scope of the workshop "Methods and challenges on the out-ofplane assessment of existing masonry buildings". The mock-ups have a U shape with one façade wall and two orthogonal sidewalls. The façade has a central opening and a gable on top, whereas the two sidewalls, acting as abutments, are either blind or have a window. A unidirectional seismic action, in the perpendicular direction to main wall, was applied. Out-of-plane behaviour of the façade was found, even if the response was clearly influenced by the presence of the window in one of the sidewalls, which led to significant torsion of the structure. The detailed description of the two tests and the conclusions are presented. The response of the mock-ups was evaluated based on the displacements, damage and collapse mechanisms developed as function of an increasing intensity earthquake testing protocol, in which a pre-processed strong ground motion component of the Christchurch (New Zealand) earthquake (February 21 st , 2011) was used. IntroductionThis paper focuses on the experimental study of the out-of-plane behaviour of masonry structures under seismic loading and provides a ground for the validation of the different approaches currently available for assessment of existing structures. For that purpose, tests were carried out in the LNEC-3D shake table with two mock-ups: one built using regular clay brick masonry with English bond and the other built using multi-leave granite stone masonry. The mock-ups have a U shape with one façade wall and two orthogonal sidewalls. A unidirectional seismic action perpendicular to main wall was applied. Several experts were invited to predict the out-of-plane seismic capacity prior to the disclosure of the test results, in what is commonly known as a blind prediction test.The main goal of the exercise was to promote a debate about the challenges of existing methods for the out-of-plane assessment of existing masonry buildings, leading to the definition of research needs, rather than evaluating the quantitative differences between the numerical predictions and the experimental results. Each participant was allowed to define the main control outputs according to the structural analysis method adopted, such as the collapse peak ground acceleration, ultimate displacement or energy dissipation.A qualitative assessment was carried out with the purpose of identifying the trends in the predictions of the damage patterns and collapse mechanisms, which allow highlighting the pros and cons of the different methods, discussing their applicability for engineering assessment of existing buildings and comparing the different results with blind experimental tests. To this end, a reference response spectrum and some basic mechanical properties were supplied to the participants, while a clear indication of the performance levels reached and corresponding response spectrum scaling factors had to be indicated b...

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The Metropolitan Area of Lisbon (MAL) has the highest population and building density in Portugal, and is exposed to medium to high magnitude earthquakes due to its geographical location. Currently, the MAL housing stock is constituted by approximately 35% of masonry residential buildings with a large variability of materials and construction techniques, as a result of many centuries of history. Most of these buildings were built before the introduction of the first design code for building safety against earthquakes (RSSCS) in 1958 and therefore were only designed to support gravity loads. Given the presence of these buildings in areas of significant seismicity, a comprehensive research is needed to assess the seismic risk and define mitigation policies for this population of unreinforced masonry buildings. The main purpose of this work is thus to geometrically characterize these typologies, through an exhaustive survey of dozens of masonry buildings collected from original drawings and identify the most important aspects that can influence their seismic behavior. After a compressive historical background, the information collected is statistically analyzed and expressed through probability distributions that can be used for the development of numerical models and derive seismic vulnerability functions, fundamental to conduct seismic risk analyses.

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