Olga Markogiannaki

University of Western Macedonia | UOWM · Department of Mechanical Engineering/ Department of Envronmental Engineering

As urbanization continues to accelerate, the concept of smart buildings has transitioned from a futuristic vision to an integral component of modern cities. These buildings, often seen as the building blocks of smart cities, are increasingly relying on cutting-edge technologies like 5G and cloud computing to reach unprecedented levels of energy eff...

The reliable assessment of bridge capacity is necessary in order to ensure the functionality of the roadway network under normal, or emergency operating conditions. Damage due to the interaction with the environment (e.g., corrosion of coastal reinforcement) has been observed in many cases, even in newly built interurban road networks. Therefore, t...

Bridges are in direct interaction with the environment and thus are exposed to various natural hazards such as earthquakes and floods, that may result in severe damage and substantial direct and indirect losses. The multiple hazard events may be subsequent single events (e.g., a flood event followed by an earthquake) or combined multi‐hazard events...

The acquisition of data regarding the performance of buildings and the use of metrics to understand their performance level are critical for efficient building management. Performance indicators are key elements in this process. They shall be clearly defined and provide the means for easily measuring building performance. These performance indicato...

Research Project INFRARES - Newsletter #12 / September 2023

Ensuring the structural integrity of bridges is crucial for maintaining road safety and minimizing traffic disruptions, as well as avoiding substantial direct and indirect economic losses. This study proposes a methodology for damage identification in R/C bridge systems by utilizing measured vibrational data from both the initial and damaged respon...

Due to climate change and the increasing CO2 emissions within the years, the European Union has set up ambitious targets for the decrease of the energy consumption until 2030, promoting funding programs for interventions that increase the energy class of the buildings. In addition, the damage level and the losses after recent earthquake events high...

Highway transportation networks play a vital role in today's economic and societal life and affect growth and employment. Hence, their undisrupted functionality and their quick recovery even after extreme natural hazard events are critical. To this end, resilience assessment of transportation networks against natural hazards is needed for decision-...

This paper presents an overview of an ongoing project that aims to develop a low-cost system and software platform for real-time identification and evaluation of the damage state of reinforced concrete bridges, with a focus on extreme events such as earthquakes. The project includes the design and manufacturing of a portable, battery-powered, wirel...

As bridge damage poses risks to both road safety and traffic flow, it can result in significant economic losses, both direct and indirect. Therefore, there is a pressing need to create and implement systems capable of evaluating the structural state of bridges. The present study puts forth a methodology that employs measured vibration data from a m...

In the current manuscript, a novel software application for Rapid Damage Assessment of RC buildings subjected to earthquake excitation is presented based on Artificial Neural Networks. The software integrates the use of a novel deep learning methodology for Rapid Damage Assessment into modern software development platforms, while the developed grap...

In the current manuscript, a novel software application for Rapid Damage Assessment of RC buildings subjected to earthquake excitation is presented based on Artificial Neural Networks. The software integrates the use of a novel deep learning methodology for Rapid Damage Assessment into modern software development platforms, while the developed grap...

Research Project INFRARES - Newsletter #8 / January 2023

Research Project INFRARES - Newsletter #7 / November 2022

The reliable assessment of the expected seismic risk (losses of all nature), at urban, regional and national level, is extremely important for the State and the society and contributes to the proper management of the pre-earthquake crisis (interventions, strengthening of buildings and infrastructures), during the earthquake, but also post-seismic....

One major issue when considering the effects of climate change is to understand, qualify and quantify how the changing climate will likely impact infrastructure assets and services as it strongly depends on current and future climate variability, location, asset design life, function and condition. Expected changes to local climatic conditions may...

The changing climate with resulting more extreme weather events will likely impact infrastructure assets and services. This phenomenon can present direct threats to the assets as well as significant indirect effects for those relying on the services those assets deliver. Such threats are path-dependent and place-specific, as they strongly depend on...

Research Project INFRARES - Newsletter #6 / July 2022

Tunnels and underground structures are constructed at an increasing rate in seismic prone areas to facilitate expanding transportation needs. The importance of these types of structures in modern societies, as well as the significant downtimes associated with seismically induced damage on them, led to an increasing interest of the scientific commun...

The use of structural health monitoring (SHM) systems on a regular basis is critical to achieve early damage detection, avoid unpredicted failures, and perform cost-effective maintenance planning. The main objective of this work is to present a model-based Damage Detection Framework for truss structural systems that uses output-only vibration measu...

Research Project INFRARES - Newsletter #5 / May 2022

Research Project INFRARES - Newsletter #4 / February 2022

Underground structures are being constructed at an increasing rate in seismic prone areas, to facilitate the expanding needs of societies. Considering the vital role of this infrastructure in densely populated urban areas and interurban transportation networks, as well as the significant losses associated with potential seismically induced damage,...

The complexity of fiber patterns within the layers of a Carbon Fiber Reinforced Polymer (CFRP) composite made with the filament winding technique has an active effect on the mechanical properties of the layer and respectively of the whole structure. While the approximation of mechanical properties in classic laminated composites is a relatively wel...

On the morning of Tuesday, November 26, 2019, at 3:54 local time, an MW 6.4 earthquake struck 16 km north of Durrës, a port city on the Adriatic coast and the second largest city in Albania. The epicenter was 33 km northwest of Tirana, the largest city and capital of Albania. Deaths and injuries were concentrated in Durrës and the village of Thuman...

Infrastructure monitoring can facilitate the evaluation of capacity and functionality loss and therefore provide valuable data and evidence for reliable, lifetime and automated risk assessments. Terrestrial monitoring systems can provide information about assets and their condition. Yet, they fall short of engineering requirements related to the hi...

Recent hazardous events in Greece, for instance, the 2021 Thessaly earthquake and floods, as well as the heavy 2019 rainfall in Crete, resulted in severe physical damage and important economic and societal losses, demonstrating the vulnerability of Greek roadway networks to natural hazards. Severe damage on bridges and tunnels of roadway networks i...

p>One major issue when considering the effects of climate change is to understand, qualify and quantify how natural hazards and the changing climate will likely impact infrastructure assets and services as it strongly depends on current and future climate variability, location, asset design life, function and condition. So far, there is no well-def...

Technical report of the Hellenic Association for Earthquake Engineering on the structural and geotechnical aspects of the 26/11/2019 Albania earthquake

Despite substantial increases in our understanding of geophysical hazards, the rates of loss from them have increased over time, largely because of increased societal exposure. Specifically, earthquake risk is increasing globally more or less in direct proportion to exposure in terms of the population and the human built environment. Although some...

Structural Health Monitoring (SHM) Techniques have recently started to draw significant attention in engineering applications due to the need of maintenance cost reductions and catastrophic failures prevention. Most of the current research on SHM focuses on developing either purely experimental models or stays on purely numerical data without real...

The current study analyzes how a geospatial intelligence application can turn into a useful operational tool in the immediate post-earthquake phase of infrastructure inspection that may have been affected by the co-seismic ground deformation due to very strong earthquake event. As a case study, the Durres (Central Albania) earthquake on November 26...

Identifying damage through Structural Health Monitoring (SHM) methods is increasingly attracting attention due to multiple maintenance and failure prevention applications. In order to create reliable SHM systems for structural damage identification (DI) tasks, access to large amounts of data containing measured structural responses is usually neces...

Large-scale civil engineering projects such as bridges, roads and dams, are critical infrastructure projects and their loss translates to a loss of movement and transportation, trade and commerce, among others. The use of remote sensing technologies (non-invasive) is an efficient solution to enhancing the condition assessment of bridges supporting...

Cable-stayed bridges have been used widely in the last 60 years in bridge construction practice and are key components of transportation networks. Therefore, the potential damages and losses, either in terms of economic cost or fatalities due to natural or man-made threats could become considerably large. Several researchers have identified the sig...

diaNEOsis report concerning the significance of bridges, the safety of the traveling public and the guidelines for the reduction of structurally deficient bridges in Greece -bridges that require significant maintenance, rehabilitation, or replacement. The number of structurally deficient bridges is increasing, and the average age of Greek bridges k...

The aim of the present study is the reduction of construction time and cost of a monolithical bridge with tall piers. The optimum combination of the criteria of safety, economy, construction speed, serviceability, durability, aesthetics and environmental harmonization is difficult to be achieved in such bridges, since factors like local geomorpholo...

The present paper attempts to demonstrate the great importance of innovative interventions οn the structural system of earthquake-resistant bridges. Τhe type of structural system affects also the construction method which will be chosen. The problem of selecting the most appropriate among the five current bridge construction methods (Cast-in-place,...

Reliable damage detection is critical for decision making on optimum design solutions and maintenance actions of structural systems. Therefore, there is the need to develop efficient methodologies for damage identification and prognosis of damage accumulation. The present study focuses on the implementation of a methodology that combines analysis w...

A vibration based computational framework for damage identification of composite cylindrical parts, produced on a spinning axis by winded carbon fibers, cascaded on specified number of plies, in various angles and directions, was presented in this work. First, a discrete FE model of the examined structure is developed, by consecutive shell and soli...

Electricity infrastructure is critical to economic growth and social development. Interruptions in the energy powersupply can have severe consequences, such as breakdowns of communication, transportation, utility systems andindustrial production processes that threaten the stability and economy of entire regions. Electricity infrastructurefaces a w...

Natural disaster risk is a crucial factor in decision making for regional planning and design. It is also critical for insurance industry and investment returns. To get qualitative or quantitative indicators for disaster risk, previous catastrophes and their direct and indirect losses should be considered. Data and statistics are important in under...

Environmental Risk Communication is a two-way process and involves the exchange of views and opinions between experts and the public/stakeholders on a potential risk (as a result of RA process). RC must consider a number of sociological, anthropological, economic and other parameters in order to be interpreted correctly by public and policy makers....

The objective of the present study is the justified selection of the most suitable construction method in the preliminary design phase of a concrete highway bridge in seismic prone areas. Earthquake resistance in bridges, as well as in buildings, is in some cases very important compared to other compliance criteria that govern their design. This ca...

The most common form of irregularity occurs in the non-uniform height of bridge piers. When these bridges are subjected to earthquake motion the shorter piers receive the largest part of seismic shear forces, while the taller ones are partially inactive. In the last years, there have been some efforts to address bridge irregularity due to pier heig...

Expansion joints are often used in buildings to divide large floor plans to statically independent structures. This practice is used to lower the effect of contraction due to temperature and creep and shrinkage phenomena. When seismic hazard is considered the required joint widths in buildings become even larger which results in high construction a...

Bridge seismic retrofit methods may focus on increasing the structural components’ capacity so that the seismic demand is exceeded, direct-conventional approaches, or on adding new ones to reduce the seismic demand, indirect approaches. The present study investigates the effectiveness and reliability of an in-direct retrofit method. It includes the...

Vibration measurements have been increasingly used to detect changes in a mechanical system's behavior and to determine damage accumulation. The continuous tracking and processing of the vibration-induced response data for damage detection in structural systems, is known as structural health monitoring (SHM). SHM comprises on one-hand methods relyi...

During the last decades, numerous research studies recognize the complex seismic behavior of bridges when soil–structure interaction (SSI) is accounted for, proposing the consideration of SSI in the estimation of bridge fragility. Furthermore, bridge damage due to recent earthquakes worldwide and the relevant direct and indirect losses, highlight t...

In current practice, large floor plans are treated with intermediate joints to create statically independent structures with layout dimensions lower than 35m. This scheme is used to minimize and-ignore‖ the effect of in-service restraints in building design. Moreover, in aseismic buildings the required joint widths are further increased due to seis...

A computational framework for dynamic analysis and fatigue damage identification of linear and nonlinear structural systems, applying a fatigue damage accumulation methodology is proposed in this work. The methodology is applied on composite cylindrical parts, produced on a spinning axis by winded carbon fibers, cascaded on specified number of plie...

The present paper focuses on the retrofit of multi-span I – Girder bridges to improve their response against earthquake events. It is widely accepted that unseating is a key seismic response issue that has led to disastrous effects in bridges not seismically designed during former earthquakes. Herein, a proposal to upgrade the performance of such b...

A computational framework for dynamic analysis and fatigue damage identification of linear and nonlinear structural systems, applying a fatigue damage accumulation methodology is proposed in this work. The methodology is applied on composite cylindrical parts, produced on a spinning axis by winded carbon fibers, cascaded on specified number of plie...

The key objective of the present paper is to present the experimental results of the mechanical response of steel bar bundles inside plastic ducts under compression. The steel bundles are part of a restraining system that has been proposed by the authors for the seismic protection of bridges against longitudinal earthquake movements.

The main goal of the present paper is to demonstrate an innovative method of indirect seismic retrofit of bridges for both horizontal seismic directions. Longitudinally a restraining system of struts-ties is applied, while transversely a ties-only. Time history analyses on R/C bridge case studies indicated remarkable improvement in the response for...

The present paper focuses on studying the use of fiber reinforced polymers (FRP) materials for limiting longitudinal displacements of concrete bridges under lateral earthquake loading. The targeted reduction of longitudinal seismic movements is achieved by applying FRP's sheets that can resist earthquake loading when activated in tension. The FRP r...

Bridges with tall piers suffer from the increase of the influence of P-δ effects and large longitudinal movements. The key objective of the paper is to suggest and investigate the performance of a longitudinal restraining system for bridge movements that accommodate P-δ effects. A possible solution for addressing large longitudinal displacements is...

The key objective of the paper is the seismic retrofit of bridges that were designed according to former design practices which were applied in bridge construction until the late 1980's in Greece. These design practices involved multi-span simply supported bridges with intermediate joints at the top of each pier. A simply supported bridge is used a...

This study proposes a new configuration for the longitudinal direction of precast I-beam bridges aimed at the improvement of their earthquake resistance. The longitudinal response of the new bridge system is different from the response of the usual "floating deck" bridge configuration, the main characteristic of which is the different seismic movem...

A smart mechanism for restraining seismic loads is presented. The mechanism retrofits the structural system and decreases the loads to the level of its capability. It consists of steel bars that behave as struts-ties. Their one edge is anchored on the bridge deck, resulting in minor works. The other edge is anchored behind the abutments' wing walls...

This paper focuses on increasing the seismic resistance of bridges by introducing a method that uses steel bars, as a struts-ties system, to restrain the seismic displacements. Reduction of the longitudinal seismic displacements is achieved by using steel bars that act under tension and compression loading, too. The conventional steel bars are appl...