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Abstract. On 6 April 2009 an earthquake of magnitude 6.3 occurred in L'Aquila city, Italy. In the city center and surrounding villages many masonry and reinforced concrete (RC) buildings were heavily damaged or collapsed. After the earthquake, the inspection carried out in the region provided relevant results concerning the quality of the materials, method of construction and the performance of the structures. The region was initially inhabited in the 13th century and has many historic structures. The main structural materials are unreinforced masonry (URM) composed of rubble stone, brick, and hollow clay tile. Masonry units suffered the worst damage. Wood flooring systems and corrugated steel roofs are common in URM buildings. Moreover, unconfined gable walls, excessive wall thicknesses without connection with each other are among the most common deficiencies of poorly constructed masonry structures. These walls caused an increase in earthquake loads. The quality of the materials and the construction were not in accordance with the standards. On the other hand, several modern, non-ductile concrete frame buildings have collapsed. Poor concrete quality and poor reinforcement detailing caused damage in reinforced concrete structures. Furthermore, many structural deficiencies such as non-ductile detailing, strong beams-weak columns and were commonly observed. In this paper, reasons why the buildings were damaged in the 6 April 2009 earthquake in L'Aquila, Italy are given. Some suggestions are made to prevent such disasters in the future.

As part of the development of a European Seismic Risk Model 2020 (ESRM20), the spatial and temporal evolution of seismic design across Europe has been studied in order to better classify reinforced concrete buildings (which represent more than 30% of the approximately 145 million residential, commercial and industrial buildings in Europe) and map them to vulnerability models based on simulated seismic design. This paper summarises the model that has been developed to assign the years when different seismic design levels (low code, moderate code and high code) were introduced in a number of European countries and the associated lateral forces that were specified spatially within each country for the low and moderate codes for typical reinforced concrete mid-rise buildings. This process has led to an improved understanding of how design regulations evolved across Europe and how this has impacted the vulnerability of the European residential building stock. The model estimates that ~60% of the reinforced concrete buildings in Europe have been seismically designed, and of those buildings ~60% have been designed to low code, ~25% to moderate code and 15% to high code. This seismic design model aims at being a dynamic source of information that will be continuously updated with additional feedback from local experts and datasets. To this end, all of the data has been made openly available as shapefiles on a GitLab repository.

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Cultural heritage is one of most significant concerns in modern societies carrying different social and historical values. Among the stock of cultural heritage, historical monuments are one of the greatest contributors to the values in many aspects. Due to several factors, such structures have gone through changes causing structural deficiencies. The aim of this study is to provide a clear insight of the cause and impacts of structural deficiencies through visual inspections and computational methods. As a representative model, Bajrakli Mosque located in western of Kosovo is selected as a case study. During visual inspections, some cracks are found along the structural elements of the mosque. A possible cause of the structural cracks may be the stress concentration through the regions of the structure. In order to provide a better understanding, two different loadings are considered to examine the structural behavior of the mosque. The first loading covers the analysis due to gravity loads, whereas the second one defines the dynamic loading due to ground shakings defined by the earthquake spectrum using finite element analysis in SAP2000. By means of these analyses, the performance of the building is examined. As a result, important data are obtained for identifying the critical regions of the structure. The maximum displacement of the structure is found to be 7.1 mm and 8.0 mm in combination of self-weight and earthquake load in X and Y direction, respectively. Moreover, the regions showing highest values of stress concentration are found through the small domes, through the openings of main dome and connections with arches, and around the openings of the walls.

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In this study a seismic performance assessment of school buildings, which have been built in accordance with template unreinforced masonry school projects in Turkey, has been conducted. For this purpose, the most widely used three template projects have been selected. The seismic performances of these buildings have been evaluated for various earthquake levels. This evaluation has been carried out in compliance with the Turkish earthquake code entered into force in 2007. The effects of material strength and plan features on the performance of masonry school structures have been investigated within the scope of this study. It has been concluded that school buildings with template design are far from satisfying the required performance criteria. For spectral acceleration of 0.80 g, which is expected in a 475 year period in the seismic Zone 1, the average exceedance ratio for life safety performance limit is more than 80% considering different material strengths. Upon evaluation of the results a building capacity index is proposed for rapid seismic assessment of masonry school buildings.