The lecture will give a concise overview of development of the disciplines of engineering seismology (and to a lesser extent, also earthquake engineering) in Croatia from a perspective of a seismologist. A significant part of the talk is dedicated to the role that Andrija Mohorovičić played in establishing the framework of research related to the seismic safety of buildings, not just in...
A ShakeOut exercise was planned to help understand potential impacts and prepare for a large earthquake in the Quebec City region, Canada. Scientific and technical knowledge was provided as the basis for a simple “drop, cover, hold on” procedure at home, school or workplace. More elaborated table top emergency exercises will also be developed for decision making by government departments and...
The continuous expansion of seismic catalogs is increasingly challenging the validity of existing ground motion prediction equations. For such real-time data, the transition of ground motion modeling toward automation became eminent. This article put forth a dynamic intelligent ground motion prediction system, automated through a novel hybridization of neural networks with a multi-objective...
The Joint Research Centre (JRC) of the European Commission is engaged in activities supporting the implementation, further development and promotion of European policies and standards for sustainable construction. Such activities include the Eurocodes (EN 1990 – EN 1999), the European Standards providing common rules for the design of buildings and other construction works to check their...
In autumn 2019 North-Western Albania was struck by series of earthquakes: the first major occurred on September 22nd (M5.6) and the second on November 26th (M6.4). After the second earthquake with more than 50 fatalities the EU Civil Protection Mechanism was activated at the request of the Albanian authorities. Immediately after mobilizing urban search and rescue teams (USAR) an EU Civil...
A vast majority of buildings built in Croatia are masonry buildings. A fair amount of these buildings was built before the development of seismic codes. Also, most of the structures that are considered to have great historical and cultural value are in fact built in masonry. If all the above is taken into account with the Zagreb earthquake being just the most recent reminder of the seismic...
Tie rods are typically used to transfer axial forces and prevent unwanted displacement on vaults, walls, arches, and buttresses in historical buildings. In order to verify their load-bearing capacity and to identify potential structural damage risks, it is very important to determine the forces transferred by tie rods and the corresponding stresses. Due to the often lack of project...
As the development of the codes of practice converges towards limiting displacements rather than forces, it is of utmost importance to be able to design the structures for predefined performance criteria. Following the objective-based design, one can accurately predict the structural displacements during realistic earthquake loading and evaluate the response of the structural elements. The...
The custom of laying out the foundation stone is a remnant of an ancient knowledge of importance of an auspicious beginning of the construction. Today, many key knowledges about building that brings a good luck to the occupants has been lost. Failure to build in proper way causes many troubles to the inhabitants.
Here we are presenting the basic knowledge of a restored science of the...
Many European cities are facing problems of decline in parts of the urban fabric due to socio-economic changes. Urban space is a ‘living tissue’ that is constantly changing due to numerous factors such as technological progress, demographic change, the need for housing and business space, etc. Just like any living organism, urban space experiences its ‘birth’, growth and decay. Urban decay is...
The 2020 Zagreb earthquake occurred on Sunday 22 March 2020. This earthquake was the first that happened during the lockdown imposed by governments to stop spreading the COVID-19. This fact makes the event interesting as a multi-hazard phenomenon. The lockdown made it not possible to deploy an earthquake reconnaissance mission. Therefore, it was necessary to undertake a remote mission...
The seismic performance assessment of an urban system can help raise awareness and improve a community’s preparedness for extreme earthquake events. Addressing this issue, the authors’ first attempt at a quantitative evaluation of a city’s performance in the event of an earthquake is presented in this paper. The assumed city model comprised of four main urban components (buildings,...
Currently, the assessment of existing structures focuses mainly on identifying, localizing, and evaluating deterioration and damage. The diagnoses are based on the design procedures of new structures and the planning of interventions often suggests reinforcement. The current practice of the assessment of existing structures might not be considered suitable to facilitate confident decisions...
After the damage of a building due to an earthquake, several steps must be followed to decide in what way to proceed. Technical evaluation of the building needs to be carried out to assess the scale of damage. Technical assessment includes considerations related to structural stability and load-carrying capacity, as well as any damage that might have occurred in non-load bearing elements (e.g....
With the increase of the population in densely populated areas, the lack of living space leads to an increase of need for upgrades to existing buildings. The problem related to upgrades is of greater importance in seismically active areas, especially in older buildings designed according to old codes. Depending on the type of upgrade, it may affect the existing structure differently, but on...
The earthquake in Zagreb on March 22, 2020 damaged many buildings, most of which were masonry and constructed before the use of earthquake-resistant construction regulations. That quake indicated the need for strengthening masonry buildings for seismic action. Seismic forces are mostly carried by the in-plane shear walls. Therefore, the main problem is proper calculation of the required...
In this paper, we will present the equipment and method by which we assess the natural frequencies on site. The data motivated us to start estimating the eigenfrequencies of structures and apply the results to calibrate FEM models. Several case studies will be presented in which the calibration method of FEM models via structural natural frequencies identified onsite were applied. The...
The paper presents a case-study of a typical residential building in the district Lower town in Zagreb historical center. The building is the representative example of unreinforced masonry buildings that were built at the end of nineteenth and at the beginning of twentieth century. Many buildings of this typology, as well as the case-study building, suffered moderate to severe damage due to...
Out-of-plane wall failures was recognized as the most common form of earthquake damage to buildings that occurred during ML 5.5 earthquake that hit the City of Zagreb on Sunday, 22nd March 2020. In this paper, a typical residential building in city centre known as Lower Town is studied. Post-earthquake building survey showed that one gable wall partially failed, while damage on several other...
The large number of catastrophic earthquakes that have occurred worldwide and their consequences point out the fact that the seismo-geological structure of the terrain represents an amplitude-frequency modifier of the seismic effect. The unconsolidated sediments lying upon the bedrock as well as the variations of the bedrock topography may increase the amplification potential of the seismic...
Earthquake resistance of structures is guaranteed through their proper design according to the seismic codes in power. In the Republic of North Macedonia, since 1981, the regulative for construction of high-rise buildings in seismic locations together with the regulative for concrete and reinforced concrete (1987) are applied, herein called Macedonian Codes. On the other hand, for seismic...
Every man-made structure induce more or less seismic energy through it’s foundations, but the most of the human casualties happens in residential buildings. Unfortunately, although most of the old houses and buildings are seismically vulnerable by default, many of the new design structures also represent threat during seismic event to their residents. Conventional aseismic standards imply the...
The latest middle and high intensity seismic events have demonstrated that the potential seismic risk of nonstructural elements compromises a building's overall seismic performance, affecting especially the building operability. Additionally, nonstructural elements account for a considerably large fraction of the total earthquake economic losses and total building costs. Several international...
This paper summarizes the experimental campaign carried out for the development of a new steel energy dissipative device named Slit Dampers (SDs) designed for earthquake protection of structures. SDs consist in shear steel plates with appropriately shaped cut-out portions of material for allowing the maximum spread of plastic deformation along the device and then maximizing the hysteretic...
The management of emergency situations generated by natural or man-made disasters is a worldwide critical task for both public and private entities. In Romania, seismic hazard represents one of the most dangerous threats, in terms of potential physical and socio-economic losses. In recent years, taking advantage of the new technology developments and increase of the computational power,...
Over the past decade, the market for cold-formed steel (CFS) systems has significantly expanded, especially for the construction of low to mid-rise buildings. CFS moment-resisting frame systems have become popular even in seismic-prone regions, mainly for single-storey portal-framed buildings of industrial use. However, their application in multi-storey structures is still limited by the...
To assess the consequences of an earthquake on building stock, it is essential to know the predominant building types, their distribution, prevalent local construction practices, and their performance in past earthquakes. The rapid assessment takes place within the first days after the occurrence of the major earthquake. It aims at fast identification of safe usage of buildings after an...
Bosnia and Herzegovina is located in the center of the Western Balkans, occupying an area of 51,197 km². This area represents one of the active seismic zones in this region which is a part of the Trans-Mediterranean-Asian Seismic belt. Looking at the Euro Mediterranean Seismic Hazard Map, Bosnia and Herzegovina falls in the Moderate Seismic Hazard having the PGA in the range of 0.08 to 0.24g,...
Seismic hazard assessment requires seismic source models representative for time spans greater than the period of earthquake catalogue completeness. In order to include seismic deformation in a several hundreds to thousands of year time interval, we need to rely on long-term geologic input in the form of fault seismogenic sources. This is particularly valid for low to moderate seismic...
The buildings with a soft storey represent a great danger for the safety of the tenants in seismically active areas. Because of the improper distribution of stiffness in height of the building, the seismic effect results in a failure in the most unfavourable way, that is, an unannounced collapse through a soft storey, whereby plastic joints are formed first in the columns, without dissipation...
Earthquake is one of those disasters which have a direct and acquit effect on human lives and settlement. At any disaster event, the importance of hospitals is out of question. Functional hospitals are a cornerstone in a coordinated national disaster response and without it the health consequence could be disastrous. Vulnerability assessment for non-structural elements of a hospital is very...
Earthquakes are rather rare in Croatia. Therefore, citizens of Croatia are less motivated in understanding the earthquakes than the citizens of e.g. California or Japan. Unfortunately, this results in difficulties which civil engineers have in fulfilling the requirements of clients and even architects. Additionally, in education and lifestyle, Croatia is traditionally oriented towards Austria...
Reinforced Concrete (RC) frame structures are designed and constructed in the major parts of Afghanistan. Meanwhile, the brick masonry wall is one of the most common material that is used as internal and external walls inside the reinforced concrete frame for the building construction. The brick masonry infill wall is defined as a non-structural element for the common structural design...
Modelling of the collapse of engineering structures due to hazardous loading conditions such as intensive seismic excitation represents a great challenge for researchers. Apart from knowing the value of the collapse load, it is very important to know the behaviour of the structure up to collapse, especially with respect to crack initiation and plastification of particular zones, behaviour of...
Bangladesh is one of the most earthquake vulnerable countries in the world. As Bangladesh is located near to the boundary of two active plates (Indian plate in the west and Eurasian plate in the east and north) the country has invariably been under threat of an earthquake that may be so harmful that may kill people to less than a moment. With the frequency of earthquakes on the increase, it is...
As natural or artificial earthen structures that provides flood protection adjacent to rivers or coastal areas, levees should be verified for several relevant design situations. For this verification, Eurocode 7 adopts semi-probabilistic approach, which utilizes statistical methods to select characteristic values of geotechnical parameters, thus neglecting spatial correlation between the same...
The common corrosion problem in conventional steel reinforcement induces a significant deterioration of the bridge pier’s yielding displacement and ductility. Superelastic shape memory alloy (SE-SMA) possesses a high corrosion resistance and retrievers its original shape upon load removal. The unique material properties attract the attention for structural design use. However, the yielding...
The proper seismic design of bridge structural bearings and expansion joints enables avoiding high repair costs after earthquakes. The paper discusses some experiences of the authors in design of bridge bearings and expansion joints according to Eurocodes. Within the scope of the detailed design of several new road overpasses, railway underpasses and railway bridges in the Republic of...
In this paper a nonlinear finite element analysis of reinforced concrete frame elements exposed to monotonic and cyclic loading is presented. The analysis was executed using 3D solid elements in DIANA FEA and frame elements with localized nonlinearities in SAP 2000. The results were verified against the experimental testing conducted at the Institute for Materials and Structures of the Faculty...
Reinforced-concrete walls have been frequently used as a bearing system for seismic loads in the last half of the century. They partially replaced the traditional European way of building with brick walls, and they are most often used for the construction of residential and business buildings of medium height. The aim of this study is to numerically examine the influence of different...
The article presents the results of the research work "Certification of real estate objects of the city of Almaty for the purpose of their survey for earthquake resistance" carried out in 2017-2018 in the Republic of Kazakhstan. Almaty is located in the zone of high seismic risk. The main purpose of the work is to obtain up-to-date data on the seismic vulnerability of buildings and structures...
In this paper, the seismic response of a 5 story reinforced concrete (RC) frame system building is analysed through the fragility analysis. The construction is designed in accordance with structural Eurocodes: EN1990; EN1991; EN1992; EN1998, as a ductility class high (DCH) system. For the analysis of the response of structural system to the earthquake actions, the methods of nonlinear static...
OGS (National Institute of Oceanography and Applied Geophysics) manages a dense earthquake monitoring network in northeastern Italy created after the 1976 Friuli earthquake that caused nearly 1000 victims. Nowadays, the network (called SMINO - Sistema di Monitoraggio terrestre dell’Italia Nord Orientale) is constituted by 43 broad-band, short and mean period seismic stations, 83 strong motion...
Due to the necessity to strengthen existing reinforced concrete structures, innovative materials such as Fiber Reinforced Polymers (FRP’s) may be used to comply with increasing loads and modern regulations. Externally bonded FRP overlays have been used to increase the flexural, shear and compressive capacity of concrete. The use of externally bonded FRP’s to confine circular concrete...
Fiber Reinforced Polymers (FRP’s) are widely used as composite materials in Civil Engineering applications in order to rehabilitate or strengthen existing structural elements. FRP’s have been used as flexural and shear reinforcement and also as a confining material mostly for concrete columns. Several studies have identified a large increase in terms of strength and axial deformation for...
This work will present a project proposal that represents the national complement of NATO-Science and Technology Organization activity SET-279 "Satellite sensor with synthetic aperture and big data technology in support of NATO operations". There is a possibility to use the acquired knowledge and experience in automatic processing of Synthetic Aperture Radar (SAR) images for civilian support...
Definition of seismo-geological characteristics of a terrain is of a great importance when it comes to selection of strong-motion station sites. Local site conditions can modify the amplitude-frequency content of the seismic motion during an earthquake. Therefore, site characterization is very significant for correct analysis and use of earthquake records.
Geophysical surveys using surface...
Urban historic centers, represented by unreinforced stone and brick masonry structures constructed before the introduction of a more demanding seismic design code, are important part of the cultural heritage. Beside their cultural-historic value, they usually represent important economic and touristic centers. Encouraged by a substantial increase in tourism, the authorities have often carried...
The behaviour of structures subjected to earthquake excitation is mostly defined by their dynamic properties. Also, they indicate the potential structural response to any unwanted dynamic excitations which may lead to uncomfortable feeling of the occupants. One of the factors that influences the structure’s dynamic properties of cast-in-place concrete systems is the construction technology....
The fundamental purpose of successful disaster risk reduction is the integration of risk aware decision making in every phase of disaster risk management and in all national development programmes. Croatian disaster risk governance is fragmented between sectors and local and national government. Risk governance and emergency management are wrongly viewed as one and the same – emergency...
A new simplified structural model, which is termed as the improved fish-bone model (IFB), is presented in the paper's first part. The model is an extension of the conventional fish-bone model. It can be used for seismic analysis of older and contemporary predominantly plan-symmetric reinforced concrete frame buildings. The IFB model approximately accounts for the importance of structural...
The importance of SSI is observed when a high rise building rests on soft subsoil where there is a need to estimate deformations caused by application of high loads from earthquake time histories. In simulation of SSI problems it is of great importance to select the most reliable time histories which would reliably adhere effects in the simulation problems.
Within this paper a ten storey...
In-plane lateral tests of timber based shear walls (e.g. light-frame or cross laminated timber walls) are the basis for the derivation of mechanical parameters required for the seismic and wind design (lateral load-bearing and displacement capacity, stiffness, ductility, etc.). The currently available testing standards, such as ISO 21581, do not provide explicit criteria for some testing...
This paper presents experimental and analytical investigation of the fastening system typically used for horizontal cladding panels in RC precast industrial buildings in Central Europe. The considered system consists of two main parts: a pair of top bolted connections, which provide the horizontal stability of the panel, and a pair of bottom cantilever connections, which support the weight of...
Railway traffic-induced vibrations are becoming one of the major environmental concerns in urban areas. Such vibrations may affect the quality of life of people settled in the vicinity of railway lines with frequent traffic. This paper contains the results from the research conducted by in-situ measurements and numerical modelling of railway traffic-induced vibrations. First, the transducers...
Zagreb 2020 earthquake severely damaged the historic centre of the City. Most of the damage occurred on historic masonry residential buildings of which many are situated in very close vicinity to the tram track. Vibrations generated by traffic can be harmful to buildings if they have been damaged by a previous earthquake. Vibrations could attribute to propagation of existing cracks. The effect...
Despite the extensive use of modern construction materials, old masonry buildings, characterized by high consumption of energy and a high risk of partial or complete destruction during earthquakes, still represent a great majority of both residential and public building stock in many earthquake‐prone countries, such as the countries in the Balkan region. Improvement of seismic resistance and...
Potresi 2020. godine bolna su trauma za sve stanovnike Zagreba, Siska, Petrinje i okruženja. Ukazali su na seizmičku neotpornost građevne supstance na koje su stručnjaci godinama upozoravali, a nitko ih nije slušao. Povijesne građevine i jezgre gradova građene prije aseizmičkog dimenzioniranja, oslabljene su dodatno uslijed neodržavanja i provizornih intervencija. Suburbana i ruralna supstanca...
In order to study local site effect on the modification of strong ground motions and dynamic response of structural systems a three-dimensional strong motion instrumentation array at Ohrid Lake basin is developed in the 80’s. This 3d strong motion array is consisted of three free field sites with one surface and three downhole instruments each, up to 125 meters to the bedrock; one nine story...
During the past earthquakes, we have witnessed extensive structural damage on modern high-rise buildings. The use of flat-slab or partially flat-slab system, inadequate seismic dilatation joints, occurrence of plastic hinges in columns, short columns mechanism, building additional storeys on already designed/constructed structures, inadequate transverse reinforcement in columns and beams and...
Presently, there is a diverse list of existing code references which could be interpreted to require seismic upgrades of existing structures, but without a clear path toward addressing the hazards, evaluation and retrofitting of existing buildings. When this comes to existing historic buildings and monuments, the topic becomes much more complex and challenging.
The problem of earthquake...
The unexpected misbehavior of buildings during the recent frequent earthquakes in Mediterranean region resulted in significant loss of human lives, injuries and economic losses due to the poor capacity of their structural systems and built-in materials to sustain seismic load. Among the lessons learned from recent earthquake in southeastern Europe is that identifying existing buildings’...
CROPOS (Croatian Positioning System) is a Croatian permanent GNSS (Global Navigation Satellite System) network featuring 33 stations distributed over the national territory at an average distance of 70 km between stations. The system was established in 2008, in the meantime enlarged and improved, and eventually, in summer 2019 it was upgraded to support observations of the European Galileo...
Lateral behaviour of RC Buildings is a great importance when it is in question the earthquake happening, so in this paper are presented the differences between buildings which have slabs without beams compared with those that in their slabs have included beams. Analysis is done for low and middle rise building, because these buildings are predominant in Kosovo and our region. The reason why we...
Infill walls significantly affect the resistance of structure. However, in the design it is generally neglected which leads to erroneous assessment of stiffness, load bearing capacity and serviceability. Seismic response of reinforced concrete frames with masonry infill can be analysed employing models of different complexity: micro-, meso- and macromodels. Macromodelling strategy, where...
Aseismic design of structures in seismic prone regions is a complex process consisting of structural system definition, selection of foundation depth and type, definition of external impacts – both, gravitational and seismic, proper detailing and definition of stability and vulnerability level. Stability of a structure is controlled by the structural dynamic response under real seismic...
Reuse of waste tyre rubber particles as a sustainable replacement for mineral aggregates in concrete has been an object of research for several years. The severe impact of rubber particles in concrete’s mechanical performance (substantial reduction of its compressive strength), has led researchers in examining the confinement via externally bonded composites as a possible solution to mitigate...
The modal pushover analysis (MPA) is an improvement of the standard nonlinear performance-based seismic evaluation of structures, based on the first mode constant force distribution over the height. The MPA is based on the theory of dynamics of structures, it retains conceptual simplicity and the computational attractiveness of a standard pushover analysis (SPA). MPA considers higher vibration...
Mass timber products are increasingly used in mid-rise to high-rise buildings. Cross-laminated timber (CLT), in particular, is highly used and plays a major role in timber construction. Balloon-type construction appears to be a particularly advantageous system when using CLT panels –it enables to avoid the compression perpendicular-to-grain in floor diaphragms and the disruption of load...
The paper shows aspects of damping modelling in nonlinear static pushover analysis (NSPA) of structures through systematization of damping types and formed flow diagram, depending on the type of applied target displacement analysis. By applying the developed flow diagram, in the process of creating and analysing numerical models of structures, it is possible to very efficiently consider which...
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 interlocking stones or a dry joint. When compared to the...
The paper will present in more detail the experiences gained and lessons learned in using aerial imagery and satellite systems after earthquakes, which have proven practical in a pandemic working conditions, given that a remote sensing is remote by default. Also, the possibility of monitoring the development of the situation, obtaining a large amount of data in a wide area of interest in a...
High frequency motion is typically observed in experimental works on seismic soil behaviour in centrifuge and in 1-g laboratory tests even if single harmonic sinusoidal input motions are imposed at base. Often these high frequencies are associated with the imperfections of the experimental setups, such as imprecise actuating systems or interaction between specimen and soil containers. On the...
Due to the rapid expansion of urban areas around the world and the ever-increasing number of reinforced concrete (RC) structures serving a variety of functional purposes, their behaviour in case of major seismic events has become of great interest to researchers and decision makers alike. Although initially designed to ensure certain levels of safety in case of earthquakes, the damage...
An assessment study of the seismic behavior of steel buildings, including their foundation system, designed according to Eurocode 8 provisions is presented. This assessment study is performed for two types of seismic motions that are not explicitly addressed in the context of Eurocode 8, i.e., the near-fault and the long duration seismic motions. In particular, by means of non-linear...
In this paper a fully automated optimization procedure of reinforced concrete structures exposed to earthquakes by using genetic algorithm-GA optimization method is implemented. Given the highly stochastic nature of the earthquake, its extreme effects and possible catastrophic consequences, special attention must be paid to solving this problem. The behaviour of structural systems was assessed...
The majority of multi-storey buildings worldwide are constructed as reinforced concrete frame structures with masonry infill walls. Whereas frames, unlike infill walls are considered load-bearing. Yet, infill walls contribute to the structure’s overall behaviour during seismic activity. Also, infill walls can impose hazard and safety issues due to Out-of-Plane instability. Consequently, this...
Dubrovnik (Croatia) and Hilo (Hawaii, USA) are two urban centers that frequently face the challenges inherent in cataclysmic tsunamis. This paper will demonstrate better practices for incorporating dynamic aquatic forces in urban planning and project-specific landscape design for metropolitan waterfronts, drawing on the specific tsunami history of Dubrovnik and Hilo; it will also identify...
Natural disasters (including earthquakes) negatively impact the physical environment and human being in many ways. Among them, post disaster housing needs have triggered multidisciplinary approaches to better address and resolve this problem. The urgent need for shelter is very high, especially after a devastating earthquake. In seismically vulnerable areas, post-disaster housing is one of the...
Paleoseismological techniques have been developed to investigate past seismic activity on faults and provide valuable data for estimating the seismic hazard of an area, especially when the historical earthquake record is much shorter than the average earthquake cycle. Paleoseismic evidence can include joints, discrete faults, folds, soft-sediment deformation and liquefaction, depending on the...
High-rise buildings in the regions with multi-hazard (MH) events, such as wind and earthquake, are exposed to more than one type of lateral excitations which act in consecutive manner. Conventionally, in such regions, the maximum of each MH event is used separately to evaluate the performance of buildings while the contribution of preceding event is neglected. When using vibration control...
Effective and efficient modeling of soil media is of importance in geotechnical earthquake engineering especially when pore pressure development is considered. Concerning the formulation of the coupled approach, a soil element is presented as a mixture of three constituents – soil grains, water and air in the pores. For the mathematical description of the coupled approach mixture theory is...
Paper summarises post disaster recovery practice in Serbia in the last decade. In the last few years (2015 - 2020) in the Republic of Serbia, several important documents (laws, bylaw, official instructions and risk assessment reports) have been adopted, which represent the basis for future methodology for assessing damage from natural and other disasters. Assessment of the building structures...
Following the M=6.4 earthquake that hit Durres in Albania on 26.11.2019, at the request of the Government of the Republic of Albania to the Government of R.N. Macedonia, in coordination with the deputy Prime Minister of the Government of R. N. Macedonia and the Director of the Bureau for Forensic Expertise of the R. N. Macedonia as operational coordinator, teams of experts were established for...
The article describes history, approaches and well-tested technologies, which have developed and have successfully applied for preventive reinforcement of insufficiently earthquake-resistant buildings of Petropavlovsk-Kamchatsky. This was required due to the short-term forecast of earthquake with M ~ 7.5 and in the corresponding of order of Russia Council of Ministers on upgrading the seismic...
Earthquake swarms are catastrophic events that affect the global strength, stiffness and ductility of existing reinforced concrete (RC) structures due to the effects of damage accumulation. Such multiple excitations can be more critical if RC buildings are exposed to highly aggressive environments. In this study, the seismic performance of a four-story RC framed structure exposed to corrosion...
The assessment of the seismic performance of historical buildings faces numerous challenges, mostly related to the diversity of the building stock and the uncertainties associated with the characterisation of the structural and construction systems. However, such assessment is essential, not only considering the human and material losses that can stem from the poor seismic performance of these...
The main objective of this paper is to present the efficiency of an innovative seismic protection of masonry infills in RC frame structures, based on polyurethane flexible joints (PUFJ). The proposed repair and strengthening method was assessed and validated through forced vibration testing of a full-scale building. The test specimen examined dynamically in the Dynamic Testing Laboratory of...
Post-earthquake assessment can be defined as a procedure to define the given structure's safety and usability after an earthquake. The seismic behaviour of buildings depends on numerous parameters such as the construction, building material, the geometry of the structure, stiffness properties and non-linear aspects, conceptual design, etc.
Brief facts about the Zagreb earthquake, the...
We present research that uses a deep convolutional neural network (CNN) based technique to predict intensity measurements (IMs) of earthquake ground shaking. The input data to the CNN model consists of multistation (39 stations), 3C acceleration waveforms recorded during the 2016 Central Italy earthquake sequence for 915 M ≥ 3.0 events. Using a 10 s window starting at the earthquake origin...
Seismic vulnerability estimation of existing structures is unquestionably interesting topic of high priority, particularly after earthquake events. Having in mind the vast number of old masonry buildings in North Macedonia serving as public institutions, it is evident that the structural assessment of these buildings is an issue of great importance.
In this paper, a comprehensive methodology...
Due to the earthquake on 22 March 2020 serious damage to thousands of buildings occurred above all in the historic centre of Zagreb. People were injured and escape routes were blocked by falling facades or parts of buildings.
Significantly mainly older and badly preserved buildings were damaged, whereas buildings built after 1964, which had to meet the requirements of the regulations for...
The reconstruction project of an existing masonry building will be presented in this paper. The building was erected in 1911. It has a ground floor and three floors. Its façade is protected as cultural heritage. We will show that the applied solutions meet the basic conservation - restoration requirements: less is more, reversibility and compatibility; and the structural designers:...
Nowadays, many Codes develop a force-based design approach, which accounts for the inelastic capacity of structures by means of a reduction coefficient, i.e. behaviour factor. At the same time, in earthquake engineering there is an ever-increasing interest on the evaluation of structural safety, through the so-called reliability analysis. Consequently, some studies analysed failure probability...
During earthquakes soil deposits are exposed to all kinds of seismic waves and are consequently subjected to three-directional cyclic loading and straining. In the geotechnical earthquake engineering practice, however, the analyses of such complex response of the deposits to seismic forces, the site response analyses, are typically reduced to the analyses of the effects of the vertically...
In the countries of the former Yugoslavia, the first regulations for the design of seismically resistant structures date back to 1964, and the reason for their adoption was the Skopje earthquake in 1963. The next, much more advanced structural code dates from 1981 with a few additions. Many RC multi-storey buildings were designed and built according to the mentioned code for high-rise...
Zagreb Cathedral was seriously damaged in the earthquake that hit Zagreb in March, 2020. The top of the southern tower broke and crashed down, while the northern tower was badly damaged. Because of high risk of collapsing and causing even greater damage to the Cathedral and surrounding buildings, it was necessary to remove the damaged part. Important and demanding phase of the removal has been...
In seismic European countries, most of the residential building stock is earthquake-prone and highly energy-intensive because it was built before the enforcement of the recent seismic and energy codes. Furthermore, this stock often shows a low architectural quality due to poor maintenance and/or construction and design deficiencies. For all these reasons, it needs deep renovation. The use of...
The area of the City of Zagreb is relatively large (~ 640 km2) and urbanized (> 800,000 residents). The general geomorphological setting of the City is on the alluvial plane of the Sava River, on the southern slopes of Medvenica Mountain and on the northern slopes of Vukomeričke Gorice, i.e. hilly area. Within this area geohazard events occur, for example: numerous landslides during last...
Recent events in Croatia revealed the high vulnerability of traditional unreinforced masonry chimney systems even in the case of moderate earthquakes. Chimney systems are non-structural elements and thus there is a lack of knowledge and research in this field. This topic has been in the focus of our research group through a recently finished two-stage research project oriented towards the...
Available evidence classifies traditional earth architecture as Croatia’s treasure as they embody authenticity and uniqueness. Thereunto, Baranja’s earth houses are presented as the best realizations of traditional Croatian rural architecture. Although present in Croatia, earth houses are often relinquished, damaged, or in an adverse state. The Act on Protection and Preservation of Cultural...
The paper deals with the structural integrity integrity of the diesel generator set (genset) foundation system aimed for the emergency power supply plant in a Nuclear
Power Plant. The genset consists of the diesel engine, the generator, and the
common base frame on elastic spring-damper elements clamped to foundations. The genset is simultaneously
exposed to the seismic load, the short...
Over the last 20 years, beside their primary educational activities, members of the Bridge Chair of the Zagreb Faculty of Civil Engineering Structural Department also worked professionally on main and execution designs of many bridges. Most of them are mid-span to large span bridges, requiring detailed seismic design, especially since their locations are predominantly in highly seismic active...
Presented is an energy dissipation analysis based design and assessment approach for earthquake soil structure interacting systems. Energy dissipation calculations are based on proper thermodynamics considerations and are developed and implemented for all components of the soil-structure system. An example is used to describe use of energy dissipation calculations for analyzing alternative...
This work presents a systematic and comprehensive review of all up-to-date official seismic hazard zonation maps and design codes for the Former Yugoslav (FY) counties. Discussed are different methodologies for calculating seismic design forces related to the different design codes and presented are the methodological and outcome differences. Official seismic zoning maps are recompiled in a...
Rapid economic and population growth in high-seismic regions and increased vulnerability of aging infrastructure has raised seismic risk around the globe. Recently, functional recovery paradigm has been introduced as a holistic approach to include not only conventional safety criteria but also novel resilience measures in seismic performance assessment and design of buildings. This paper...
The abstract In the past thirty years, significant efforts have been made toward establishment of uniform criteria for empirical performance evaluation based on earthquake damage classification and seismic evaluation of buildings. Developed empirical performance criteria have been used in many countries for estimation of physical, functional and economic losses, planning for reconstruction of...
The seismic performance of a structure is determined by a series of factors that are related with the earthquake source characteristics, site effects and structural capacity, among others. The state of the art of seismic vulnerability assessment methods, using probabilistic approach, are capable of incorporate the effect of some of these factors. Within the epistemic uncertainties, the soil...
Croatian bridges have been built in different times, always in step with or even ahead of the world's achievements.
In seismically active areas it is of paramount importance to design bridges with ductile behavior. Many bridges built before the modern Eurocodes came into force were designed to standards which did not offer provisions for structural detailing allowing for their ductile...
Unreinforced masonry building (URM) are rather vulnerable to the influence of stronger earthquake motions. This was confirmed during recent earthquake which hit the capital of Croatia Zagreb on 22nd of March 2020, as well. The most damages were registered on older masonry structures. During great rebuild after the World War II large stock of multi-storey residential buildings, mostly 3 to 6...
Application of modern seismic design codes in everyday practice imposes a need for the seismic retrofit of existing structures, which represents a challenging task when it comes to old masonry buildings. Many of such buildings were built long before design codes, not just seismic ones, and in many cases their structural performances do not conform with the current design criteria. Seismic...
The wider area around the city of Zagreb is one of the seismically most active regions in Croatia where many strong events have been reported in the past. Due to the large population and socio-economic importance of this region, advanced seismic hazard and risk assessment for this area is of high importance. While seismic hazard gives probability that an earthquake will occur and outlines...
The physics-based assessment of seismic risk and its unbiased perception in the community is necessary to enhance community seismic resilience. As a step towards this objective, a seismic stress test of building stock in Slovenia was performed last year. The stress test outcome was negative, which was communicated to the Ministry by means of a preliminary seismic performance certificate of...
The lack of interest in replacing or strengthening unsafe buildings is primarily due to limited personal experience with the damage caused by major earthquakes. However, while strong earthquakes are rare, the seismic risk can be significant due to their potentially catastrophic consequences. To help establish an unbiased perception of seismic risk in society, we conducted a seismic stress test...
A significant number of masonry buildings, built prior to existing seismic codes, nowadays are used and serve a function as public institutions, namely schools, administration offices, courts, museums, theatres, etc. The necessity for evaluation of the seismic risk of these existing buildings is of high priority. In the framework of the research project SeismoWall, sixteen representative...
Most unreinforced masonry structures are vulnerable to seismic actions. Due to the poor shear and bending resistance of masonry walls, seismic actions can sometimes produce mechanisms that may lead to the collapse of the building. This paper presents the results of a shaking table test performed on a 1:2 scale unreinforced masonry building. The results consist of a map of cracks that appeared...
The paper presents the results regarding the behaviour of a structural model made of Glass Fibre Reinforced Mineral Matrix Composite tested to various seismic actions on the shaking table. The model dimensions are 3.40 m x 3.40 m x 3.00 m meaning width x length x height. The structure was made of multiple prefabricated panels pre-assembled directly on the shaking table. The final shape of the...
With the development of the new technologies and the modern residential and industrial buildings typology the non-structural components and systems become major part of the total value in building construction. This damage may result in loss of functionality, economic loss due to damage and even life safety hazards. Since they are not amenable to traditional structural analysis, full-scale...
The continuous increase in population coupled with migration towards urban areas put pressure on the building stock and increased the demand for housing and office buildings. Some of the most densely populated regions are located in areas prone to natural disasters out of which earthquakes are of particular interest for designers and researchers in the field of civil engineering because of...
Since numerical modelling of soil properties in seismic design of buildings is usually a complex and demanding task, practicing engineers and researchers aim to keep numerical models as simple as possible. Therefore, the goal of this research is to verify soil-structure interaction (SSI) modelling parameters for buildings founded on compliant soils. For this purpose, the results of a...
Potresi, poplave, požari, klizišta i ratna razaranja, sve se to dešavalo u Republici Hrvatskoj u relativno novijoj povijesti. Počevši od obnove nakon snažnog potresa u Dubrovniku i Stonu te velikoj poslijeratnoj obnovi, domaća i strana iskustva su se akumulirala kroz godine.
Potres jačine 5,5 prema Richteru koji se desio 22. ožujka 2020. u Zagrebu i niz slabijih potresa koji su uslijedili...
In the morning of 22 March 2020 at 5:24 (UTC) a damaging earthquake struck Zagreb, the capital of Croatia. This shallow local magnitude 5,5 earthquake was the strongest instrumentally recorded earthquake in the NW part of Croatia since 1908 when the first seismological station was installed in Zagreb. The strongest aftershock of local magnitude 4,9 happened at 6:01 (UTC) on the same day. Both...
Generation of Fragility Curves (FCs) forms the primary basis for seismic vulnerability assessment of structures within a probabilistic framework, which can effectively aid in seismic damage mitigation. This paper presents the system-level FCs generated for a class of reinforced concrete integral abutment bridges, in succession to the component-level FCs developed for the damageable components...
Externally bonded Fiber Reinforced Polymers (FRP’s) are frequently used in civil engineering applications in order to rehabilitate or strengthen existing structural elements. FRPs have been successfully used as flexural or shear reinforcement. However, they exhibit some significant drawbacks such as impermeability, loss of strength at elevated temperatures, and combustibility during a fire....
The research that gave rise to the following text is part of the institutional research project at Zagreb’s Faculty of Architecture entitled “Rebuilding Zagreb after 2020 Earthquake” with the sub-topic: „Earthquake (non)resistance and housing estate in Zagreb“. One of the aims of this research is to analyse the resymbolization of Zagreb that took place after the earthquake. Images of sheer...
Proximity of the active faults in Croatia is being studied for evidence of past earthquakes by archaeoseismology. Excavations of the Roman city of Siscia (Sisak, Croatia) yielded large chunks of thick brick walls (considered to be the city wall), collapsed in the adjacent ditch in their entirety. The wall is made of brick masonry on both sides and a thick concrete infill between them. Much of...
The Mw = 6.4 November 26, 2019 02:54 UTC earthquake struck near the city of Durrës, Thumanë. The earthquake struck on 26 November, resulting in 51 deaths and up to 750 people injured. Many buildings in Durrës and Thumanë were collapsed and many others were seriously damaged. The inspection of the damaged buildings and declared uninhabitable, revealed many problems related to their design....
On November 26th 2019 the Mw=6.4 earthquake struck the north-central Albania causing casualties and severe damage (IEMS = VIII) to the built environment, and in particular to the city of Durrës. This earthquake occurred not long after the Mw=5.6 earthquake on September 21st 2019. In January 2020 the American Concrete Institute (ACI) Technical Committee 133 Disaster Reconnaissance task group...
Cultural heritage, both tangible and intangible, is a unique expression of human achievement in the past and provides invaluable insights into our evolution and identities. The meaning and the treatment of cultural heritage through the history has been constantly exposed to changes but in the last century it finally takes the rightful place.
Historical buildings, monuments and archeological...
On March 21, the Croatian Government (following a suggestion of the Civil Protection Coordination Center) introduced a “stay at home” order for the whole country due to the pandemic, and the very next day a magnitude 5.5 quake shook the northern part of Croatia, mostly damaging the capital city of Zagreb and its nearest urban satellites, affecting almost 1 million people in total.
Natural...
Nowadays, underground structures play a crucial role in transportation and utility networks in urban areas. Their static design has achieved a high level of accuracy. Instead, tunnels' efficient seismic design is not yet completely gotten, even due to the complex soil-tunnel interaction phenomena that occur during an earthquake. So, the few code regulations and guidelines about the seismic...
The paper explains in more detail the fifteen-year agreement of the Sendai Framework for Risk Reduction through seven global goals and four priority actions.
Relevant are the experiences of earthquakes in Skopje, Dubrovnik and the Montenegrin coast, which resulted in stricter regulations for securing buildings from seismic destruction in the SFRY regulations. In the case of Skopje in 1963, a...
Extensive experimental and analytical research have been performed, led by the third author during three and a half years, in the Institute of Earthquake Engineering and Engineering Seismology (IZIIS), Ss. Cyril and Methodius University in Skopje, in the frame of the innovative NATO Science for Peace Project “Seismic Upgrading of Bridges in South-East Europe by Innovative Technologies (SFP:...
In the Institute of Earthquake Engineering and Engineering Seismology (IZIIS), Ss. Cyril and Methodius University in Skopje, extensive experimental and analytical research have been performed led by the third author, in the frame of the innovative NATO Science for Peace Project “Seismic Upgrading of Bridges in South-East Europe by Innovative Technologies (SFP: 983828)”. The specific project...
2020 Zagreb earthquake and 2020 Petrinja earthquake raised the topic of urban renewal process and possible renewal models for damaged buildings. The paper presents the author's research from the first semester of the Postgraduate doctoral scientific study programme Architecture and Urban Planning at the Faculty of Architecture in Zagreb.
The main goal of urban renewal is the process of...
Earthquakes can lead to widespread damage to the built environment, affecting many residential buildings and expose their residents to potentially severe and long-lasting physical and financial stress. While emergency response actions are still ongoing in the aftermath of such an event, public officials already have to take first decisions that will shape the reconstruction process and affect...
During a catastrophic event, the ability of the personnel responsible for responding to such an event is due not only to a pre-existing knowledge or ability, but also to the degree of familiarity with the scenario that must be faced. Especially in the case of high-impact but potentially unlikely events, an appropriate response is based on the fact that staff are able to perform their assigned...
Wall Index (WI), also known as “wall density”, is a ratio of the total cross-sectional area for all structural walls aligned in one direction of the building’s floor plan and the gross floor plan area. Reconnaissance studies after past earthquakes in countries like Chile, Mexico, and China, confirmed that WI is one of the key parameters related to seismic performance of loadbearing masonry...
Following the damaging 2020 earthquake of 22 March 2020 (Mw 5.3), a question was raised if this was the largest event after the Great Zagreb earthquake of 1880 (Imax = VIII MSK). The counter-candidates are the events of 17 December 1905 and 2 January 1906. Relevant earthquake catalogues largely disagree when the magnitudes of the Zagreb earthquakes of 1905 and 1906 are concerned. The reported...
