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Serbian Association for Earthquake Engineering (SUZI-SAEE) is a national non-governmental (NGO) technical association with a mission to enhance awareness among professionals and general public related to the earthquakes and their consequences. SUZI-SAEE has several technical committees, including the Learning from Earthquakes (LFE) Committee, which is engaged in compiling and disseminating lessons from significant earthquakes in the country and the region. The activities include physical and/or virtual visits to earthquake-affected areas. The overarching goal is to reduce earthquake losses, increase community resilience and speed up post-earthquake recovery process in Serbia and other countries in the Balkans. The committee is also working on the development and application of advanced field reconnaissance tools, such as drone footage, data collections app, etc. In the last four years, SUZI-SAEE has dispatched expert teams to assess the impact of the November 26, 2019, Durres, Albania earthquake, the December 29, 2020, Petrinja, Croatia earthquake, and February 2023 Kahramanmaras, Turkey earthquake sequence. Several members were also involved in virtual reconnaissance visits after the 2021 Nippes, Haiti earthquake, the November 2022 Indonesia Earthquake, and November 2022 Duzce, Turkey Earthquake. Activities of the LFE committee are relevant for individuals and organizations responsible for education, seismic design, post-earthquake damage assessment, as well as for state authorities responsible for enacting laws and programs related to earthquake risk mitigation. The committee is making efforts to cooperate and share experience with similar committees around the world as well as jointly work on future reconnaissance missions, building on the past successfully accomplished collaborations.

During a one-year period, several moderate intensity earthquakes occurred in the Balkan Peninsula, including four significant earthquakes, two of which had the same magnitude of Mw 6.4. The first earthquake took place on November 26, 2019, in Albania, and the second occurred on December 29, 2020, in Petrinja, Croatia. Following both events, the Serbian Association for Earthquake Engineering (SUZI-SAEE) dispatched expert teams to assess the earthquake impact on the built environment and assist in damage evaluation. Both events had devastating effects on for the building stock in the epicentral area. However, notable differences were observed between these two events and they are presented in this paper. This paper provides an overview of the most common types of failure, highlighting structural deficiencies, as well as examples of good behaviour in each earthquake. Additionally, recovery aspects of the earthquakes are compared, and the aim is to summarize key findings that could serve as a basis for lessons to help communities in the Balkan region prepare for and respond effectively to future earthquakes.

The paper discusses consequences of the February 6, 2023 earthquake sequence (a M 7.7 earthquake with epicentre in Pazarcik, followed by a M 7.5 earthquake with epicentre in Elbistan) which affected south Türkiye and northwestern part of Syria. The earthquakes caused more than 56,000 fatalities. More than 230,000 buildings experienced severe damage or collapse, while additional 40,000 buildings experienced moderate damage. The focus of the paper is on the performance of reinforced concrete buildings, which are prevalent in the affected area. The causes of structural damage are discussed in the context of the local codes, and in design and construction practices. Extensive non-structural damage was observed in these buildings, and it was caused by flexible RC frame system and inadequate amount of RC walls. The topic is relevant for Serbia since reinforced concrete is prevalent technology for buildings in our country, and some similarities in construction practices exist in Serbia and Türkiye.

Developing a classification system (taxonomy) for buildings is a critical step for seismic risk assessment studies. Such a system can be used to characterize a building portfolio within urban/rural settlements or building stock for the entire country. Serbia is located in a region characterized by a moderate seismic hazard. In the last century, 10 earthquakes of magnitude 5.0 and higher occurred in Serbia, the strongest (M 6.0) in 1922. The strongest earthquake in the 21st century (Mw 5.5), with an epicenter close to Kraljevo, occurred in November 2010 and caused significant damage to residential buildings. In 2019, members of the Serbian Association for Earthquake Engineering (SUZI-SAEE) contributed to the SERA project and its goal to develop a seismic risk model for Europe. A taxonomy of residential buildings in Serbia was developed based on previous national and regional building stock studies. The proposed taxonomy includes the Lateral Load-Resisting System (LLRS) (e.g., wall, frame, dual wall-frame system) and material of the LLRS (e.g., masonry, concrete, wood) as the main attributes. The type of floor diaphragm (rigid or flexible) has been specified only for masonry typologies with unreinforced masonry walls, while building height and date of construction have been implicitly considered. According to the proposed taxonomy, there are 9 residential building typologies in Serbia; out of those, 5 typologies are related to masonry structures, 3 are related to RC structures, and one is related to wood structures. This paper describes the proposed taxonomy and outlines the characteristic features of different building typologies and their relevance for estimating seismic vulnerability and risk. A comparison of the proposed taxonomy for Serbia and published taxonomies for Croatia is also presented.

The paper describes a novel Adriseismic method for exp4editious assessment of seismic risk associated with unreinforced masonry buildings. The methodology was developed for the Adriseismic project of the Interreg ADRION programme, with the aim to develop and share tools for increasing cooperation and reducing seismic risk for six participating countries within the re-gion surrounding the Adriatic and the Ionian Seas. The method is applicable to unreinforced ma-sonry buildings characterised by three main seismic failure mechanisms, namely masonry disin-tegration, out-of-plane failure, and in-plane damage/failure. Depending on the input parameters for a specific structure, the assessment yields a qualitative output that consists of the masonry quality index, the index of structural response, the level of seismic risk, and the most probable collapse mechanism. Both input and output of the method are applied in the spreadsheet form. The method has so far been applied in urban areas of participating countries in the project, including Mirandola, Italy; Kaštela, Croatia; Belgrade, Serbia. In parallel, the methodology has been validated by performing a detailed seismic assessment of more than 25 buildings, and the results have been compared with the results of the proposed expeditious method. The results show a good correlation between the two methods, for example, the structural response index obtained from the expeditious method and the capacity/demand ratio obtained from the conventional assessment method.

Seismic safety of schools should be one of the highest priorities for each community. Besides being important to design the school buildings such as to avoid damage or collapse in earthquakes, they should also remain safe and functional as a shelter for evacuation after an earthquake. The aim of this paper is to raise awareness of the importance to study and assess the seismic risk of existing schools, as well as to emphasize a need for adequate seismic design of new school buildings. Examples of damage in school buildings due to recent earthquakes in the region were presented since they are relevant for Serbia. Observations from the survey of school buildings in Serbia have been used for a comparison with the representative examples of damaged school buildings in Croatia and Albania, thus deriving the conclusions of what could be expected in Serbia in a case of moderate earthquake.

In the period of one year, several moderate intensity earthquakes occurred in the Balkan Peninsula. It is interesting that among four significant earthquakes in this period of time, two with the same magnitude (Mw 6.4) occurred. The first was on November 26, 2019 in Albania and second one on December 29, 2020 Petrinja (Croatia). Both events were quite devastating for the building stock in the epicentral area. Since most of the buildings in Balkan Peninsula are masonry buildings (single or multi-family apartments), this paper focuses on the performance of these buildings during the mentioned earthquakes. Quickly after both events, Serbian Association for Earthquake Engineering (SUZI-SAEE) organized an expert teams to visit affected areas. The goal was to document the consequences of the earthquakes on the built environment, as well as to provide support in damage assessment. Data collected during the visits is usded investigate the performance of masonry buildings. Most common types of failure are presented, pointing out the deficiencies in the behaviour of masonry structures. However, examples of good behaviour (mostly related to the well-constructed confined masonry buildings) are also presented.

Past earthquakes have affected millions of people whose lives changed within a minute, and caused damage or collapse of thousands of buildings and infrastructure systems. In many cases, earthquakes have long-term consequences. Therefore, it is very important to study the effects of damaging earthquakes and share the lessons and field experience with technical professionals and general public. The authors are members of Serbian Association for Earthquake Engineering (SUZI-SAEE), which organized reconnaissance visits to the areas affected by the November 26, 2019 Durrës, Albania earthquake (Mw 6.4) and the December 29, 2020 Petrinja Croatia earthquake (Mw 6.4). This paper presents findings on the performance of reinforced concrete buildings in these two events. Characteristic damage patterns are presented in the paper, along with the explanation of the causes of damage and recommendations for future engineering practice in the affected countries and the region.

Masonry buildings constitute a major fraction of the building stock in Serbia and other countries in the region, and they are highly exposed to the earthquakes and affected due to their vulnerability to seismic effects. This paper presents observations related to the seismic behaviour of masonry structures during recent earthquakes in the region, and outlines the common damage patterns. This was used as a basis for understanding the seismic behaviour of masonry buildings and choice of the feasible seismic retrofitting techniques. Finally, an overview of seismic retrofitting techniques for masonry buildings is presented, along with the examples of field applications.

The collapse and damage of large number of buildings during the November 26, 2019 (Mw 6,4) Albania earthquake caused 51 fatalities and injuries to at least 910 people. Most of collapsed or heavily damaged buildings were RC frame buildings. Although RC frame system is considered as very ductile seismic force-resisting system, its behaviour during earthquake highly depends on: (1) regularity in plan and elevation, and (2) global and local ductility. Based on the authors’ visit to the earthquake-affected area on behalf of the Serbian Association of Earthquake Engineering and observations of collapsed and damaged buildings, it was concluded that among main reasons for underperformance of these flexible systems were inadequate analysis of interaction between infill walls and RC frames and reinforcement detailing of RC members

Recent earthquakes in Balkan, including the September 21 and November 26, 2020 Albania earthquakes, March 22, 2020 Zagreb earthquake, and the December 29, 2020 Petrinja, Croatia earthquakes had devastating consequences for the affected population of these countries. Besides substantial structural damage of RC buildings as well as loadbearing masonry buildings, these earthquakes caused significant damage of non-structural masonry elements. This paper presents examples of the damage for loadbearing and non-structural masonry walls (infills and partitions) due to out-of-plane seismic effects, as observed by the authors during the reconnaissance visits to the affected areas. This type of damage can prevent the evacuation of people from the buildings during the earthquake, as the falling masonry elements block the evacuation routes, and hinder the reoccupancy and functional recovery of affected buildings after an earthquake. The authors recognize that both loadbearing and non-structural walls (infills and partitions) experienced out-of-plane collapse due to lack of connection to the floor/frame. Using the examples of the damage or failure of masonry walls during the recent earthquakes, their failure mechanisms were explained and the lessons learned were summarized in the paper.