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Traditional houses represent landmarks of local cultures all over the world. In seismically prone countries, the traditional timber frames with different types of infills have shown quite good earthquake resilience, an essential feature considering their large number, their simplicity and their reduced cost, owing to the use of local materials and workmanship. In fact, their seismic behavior fostered the interest in further scientific research, including that addressing engineering aspects. Because of their diversity in layout and detailing, noticeable even among houses in the same area, developing general methods to preserve and strengthen such buildings is still a difficult task. This paper presents an overview of the traditional building construction techniques in Romania, focusing on the structural configuration and detailing of the so-called paiantă houses. Largely used all over the country, these houses have shown that they can generally withstand earthquakes at least without collapsing and, most frequently, with minor or repairable damage. Their preservation is nowadays a major challenge, as they are being gradually either demolished and replaced, or retrofitted by using invasive techniques. Their cultural and heritage value is undeniable, and there are still many things to be learned from the past craftsmanship and re-valuated in the future. Three case studies of rural buildings located in different areas of the country were chosen among the most widespread paiantă versions, and comprehensive engineering assessments were conducted to identify their detailing and degradations. Based on the most common degradations, the conclusions drawn from this study can be used to substantiate further research aimed at selecting the most appropriate construction and strengthening techniques.

The newly proposed structural system (TRAROM), made of timber posts, beams, internal diagonals and planks laid on orthogonal directions on both sides of the wall, is influenced by the architecture ...

This paper is focused on the seismic risk assessment of Buzau County in Romania. This county overlays the most active seismic source in the region, namely, the Vrancea intermediate-depth se...

Traditional houses represent landmarks of local cultures all over the world. In seismically prone countries, the traditional timber frames with different types of infills have shown quite good earthquake resilience, an essential feature considering their large number, their simplicity and their reduced cost, owing to the use of local materials and workmanship. In fact, their seismic behavior fostered the interest in further scientific research, including that addressing engineering aspects. Because of their diversity in layout and detailing, noticeable even among houses in the same area, developing general methods to preserve and strengthen such buildings is still a difficult task. This paper presents an overview of the traditional building construction techniques in Romania, focusing on the structural configuration and detailing of the so-called paiantă houses. Largely used all over the country, these houses have shown that they can generally withstand earthquakes at least without collapsing and, most frequently, with minor or repairable damage. Their preservation is nowadays a major challenge, as they are being gradually either demolished and replaced, or retrofitted by using invasive techniques. Their cultural and heritage value is undeniable, and there are still many things to be learned from the past craftsmanship and re-valuated in the future. Three case studies of rural buildings located in different areas of the country were chosen among the most widespread paiantă versions, and comprehensive engineering assessments were conducted to identify their detailing and degradations. Based on the most common degradations, the conclusions drawn from this study can be used to substantiate further research aimed at selecting the most appropriate construction and strengthening techniques.

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.

Masonry-infilled timber frames are widely used for residential houses in underdeveloped rural and mountainous areas in southwestern China. As suggested by the identified dynamic properties of three typical timber houses of this type, the structure can be taken as a dual system in which the masonry infills provide the most lateral resistance, while the timber frame withstands the vertical loads. The seismic damage to the houses, either of masonry or of masonry-infilled timber structures, in a small town near the epicenter of the 2013 M7.0 Lushan earthquake in southwestern China was inspected and compared, in order to show that the masonry-infilled timber houses exhibited much better seismic performance than the unreinforced masonry ones during the earthquake.

Europe is a continent that is subject to significant seismic activity. Thus, the buildings’ seismic behaviour must be analysed, including not only the new structures, designed under more rigorous codes, but also older ones. This article examines a traditional type of building that uses timber frame/masonry, which is found in Portugal, Turkey, France, England, Greece, Romania, Italy, Spain, Germany and Scandinavia. Although the structures differ in terms of construction details, their structural system is basically the same: the wooden structural system bears mainly the horizontal loads while the masonry supports the gravity loads. The study includes a brief report on the seismicity of each country where this traditional type of building made of timbered framed masonry is found, together with the description of these buildings’ constructive systems., Europa es un continente que está sujeto a una significativa actividad sísmica. Por esta razón, se debe analizar el comportamiento sísmico, no sólo de las nuevas estructuras, diseñadas sobre la base de códigos más exigentes, sino también de los diversos tipos de estructuras antiguas. En este artículo se analizan las estructuras constituidas por mampostería y madera, que se pueden encontrar en Portugal, Turquía, Francia, Inglaterra, Grecia, Rumania, Italia, España, Alemania y Escandinavia. Aunque estas estructuras presentan diferencias en cuanto a detalles constructivos, su sistema estructural es idéntico: el sistema estructural de madera absorbe principalmente las cargas horizontales, mientras que la mampostería garantiza la resistencia a la acción de la gravedad. El estudio presentado incluye un breve informe acerca de la sismicidad de los países en que existe el tipo de construcción mencionado, conjuntamente con la descripción de los sistemas constructivos específicos de cada país.

Although the timber framed masonry structures are considered earthquake resistant, for many of them the construction details are poor. Connections are the weakest parts of the system, especially the bottom ones, at every floor level or at the connection with foundation. Also, in past earthquakes out-of-plane collapse was observed usually for the upper masonry panels, though without causing a general collapse of the building. Since for some countries (Portugal, Italy, Greece, Haiti, etc.) the system can be found in heritage buildings, a retrofitting solution was studied in order to improve the behavior of timber framed masonry structures. Thus, AFRP sheets (uni-directional and bi- directional) were applied on a full scale timber framed masonry wall part and in-plane static cyclic tests were conducted. The retrofit solution, all layouts, proved to be efficient, with a 70% increase in strength for two of the specimens and 26% for the third, respectively. Based on the test results a simplified strength evaluation was calibrated for the contribution of the AFRP sheets.

A recent study in Bucharest emphasised the need to rehabilitate 392 vulnerable buildings, but when investing in seismic strengthening, the authorities are facing both financial and technical obstacles. For this reason the present paper is studying the possibility to use the incremental seismic rehabilitation (ISR) method to Romanian damaged and/or vulnerable buildings that present a higher risk of collapse in case of a major earthquake. Also, it proposes a tool having as base the critical path method to help the implementation of ISR methodology.

Traditional architecture with timber-framed masonry (TFM) system was used in many countries prone to seismic events due to its earthquake-resistant performance. In this context, Romanian TFM buildings were constructed by local builders applying non-engineered measures to reduce seismic vulnerability. However, the seismic safety assessment of these buildings still presents open issues due to material modeling, and in simulating the complex interaction between structural elements. Although the seismic response at building scale depends on a combination of factors such as geometry, boundary conditions, quality of construction, structural connections and interactions, it is significantly influenced by the in-plane behavior of TFM walls. The present paper aims to investigate the seismic performance of Romanian TFM walls by using a simplified equivalent frame model, in OpenSEES software, with linear elastic elements and nonlinear behavior lumped at the connections. Indeed each joint is modeled with nonlinear springs, one per degree of freedom, for which the parameters were initially calibrated based on representative experimental tests in literature. After this calibration, the resulting parameters were updated to approach the local and global responses from the experimental campaign performed at the Technical University of Civil Engineering of Bucharest in terms of initial stiffness, maximum base shear, and total dissipated energy. The simplified modeling strategy requires limited computational efforts and provides information about the role of each connection., The work was partly financed by the scholarship of the SAHC Consortium.