Shake table testing of aggregate masonry buildings

Masonry building aggregates can be found throughout historical city centers of Europe. Adjacent buildings have often developed during the long densification process, without consistent planning or engineering. It is common for neighboring units to share a structural wall with the connection between the units ensured through interlocking stones or a dry joint. Another consequence of the gradual development through the years are the different material properties, distributions of openings, and different roof and floor heights of the neighboring units. The difference in properties and the uncertainty related to the connection between the units leads to difficulties when modelling the seismic response. For that reason, units of an aggregate are often modelled as separate or perfectly connected. Both simplifications can lead to an incorrect estimation of the aggregate response. One of the principal reasons impeding the advancements in this area is the lack of large-scale experimental campaigns, due to the size and the cost of such campaigns. For that reason, the project AIMS (Seismic Testing of Adjacent Interacting Masonry Structures), included in the H2020 project SERA has the objective to provide the experimental data on the behaviour of an aggregate of two stone masonry buildings under bi-directional horizontal acceleration. The test unit is constructed at half scale, with one storey building and a two-storey building. The buildings share one common wall and the façade walls are connected by dry joints. Units have different floor heights and floor beam orientations, leading to a complex dynamic response. The shake table test is conducted at the LNEC seismic testing facility. Extensive instrumentation, including an optical displacement measurement system, displacement transducers, and accelerometers are used to provide information on the force-displacement response. Special attention is devoted to the interface opening and the global behaviour in relation to the interface separation.

Blind predictions of shake table testing of aggregate masonry buildings

Katrin Beyer, Andrea Penna, Igor Tomic

In many historical centers in Europe, stone masonry is part of building aggregates, which developed when the layout of the city or village was densified. The analysis of such building aggregates is very challenging and modelling guidelines missing. Advances in the development of analysis methods have been impeded by the lack of experimental data on the seismic response of such aggregates. The SERA project AIMS (Seismic Testing of Adjacent Interacting Masonry Structures) provides such experimental data by testing an aggregate of two buildings under two horizontal components of dynamic excitation. With the aim to advance the modelling of unreinforced masonry aggregates, a blind prediction competition is organized before the experimental campaign. Each group has been provided a complete set of construction drawings, material properties, testing sequence and the list of measurements to be reported. The applied modelling approaches span from equivalent frame models to Finite Element models using shell elements and discrete element models with solid elements. This paper compares the first entries, regarding the modelling approaches, results in terms of base shear, roof displacements, interface openings, and the failure modes.

2021

Blind predictions of shake table testing of aggregate masonry buildings

Katrin Beyer, Andrea Penna, Igor Tomic

2020

Modelling historical masonry aggregates using the Equivalent Frame approach

Katrin Beyer, Igor Tomic, Francesco Vanin

Many historical centres in Europe, including the city centre of Zagreb, feature masonry building aggregates, which developed as the building layout of the city was densified. Adjacent buildings in aggregates often share a structural wall and the building that was constructed second connects to the wall of the first building through a dry joint. When compared to the response of single freestanding buildings, several factors make the seismic response of masonry building aggregates more complex: It is not unusual for adjacent units to have different material properties, area and distribution of openings, roof and floor heights and orientations, and construction details.

2021