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Masonry infilled timber frames (TFM) are widely used for residential houses in many countries in the world. Last two decades’ seismic events showed that this typology is resilient for earthquakes, and even though it exhibits damages, it rarely collapses. For developing countries, TFM is a valid solution for life protection of the inhabitants. Interaction between timber and masonry is difficult to assess and although numerical models simulate roughly the seismic behavior of TFM, they need expensive resources (time and software) to reach acceptable accuracy level. For this reason, this study proposes a simplified seismic evaluation method for timber framed masonry walls, based on a shear spring model calibrated with experimental result. The resulting envelope curve simulates satisfactorily the initial stiffness and maximum strength.

The Romanian territory has an important seismic potential in Europe, with the Vrancea source. The most destructive seismic events that occurred in Romania in the 20th century (November 10, 1940 and March 4, 1977) have revealed a high level of seismic vulnerability of the built environment. An important part of this built environment is represented by historical buildings, including the traditional ones (timber frame and infills from various materials as brick, stone, adobe, etc.). The investigations after seismic events from November 10, 1940 and March 4, 1977, revealed that the traditional buildings did not suffer any or important damages, thus showed their particular seismic behavior. Both the experience after similar seismic events from other countries as Turkey, Haiti, China, Myanmar, etc. and research studies from countries like Portugal, France and Japan, revealed an unexpected good behavior of such of buildings. Therefore, in this paper the results of the static cyclic tests on walls are presented. The test specimens were built according to the findings of the field investigations done on traditional buildings from Romania which are briefly presented hereby. The typology on which this paper focuses is the one found as predominant in the investigated areas (around the Vrancea seismic source).

A lightweight structural timber system is proposed, inspired from traditional Romanian architecture, and adapted to the current needs (wider spaces and increased comfort) and to the local construction market (low skill workforce, poorly controlled material quality, diversity of materials). A good seismic behavior was, also, a target, because Romania is one of the most seismic prone countries in Europe. In order to satisfy these requirements, a team of researchers, an architect, and design and construction site engineers gathered and tested walls with a new structural system inspired from a certain traditional house type. The tests were conducted in-plane in static cyclic loading. Several parameters were tested on 8 distinct specimens: the layout of the timber elements and that of the screw nails. As a waypoint in the project, a layout that was deemed the most satisfying (by considering strength capacity and manufacture parameters), so three additional specimens were tested to check variation of the results on this layout. The paper presents the details of the proposed system and also the main seismic characterization parameters. The resulting best layout is to be proposed for a house, as an example project, in order to be used by the government for reconstruction in case of disaster recovery (earthquake, floods), but also for other interested parties.