Xavier Romão

• Associate Professor
• University of Porto

The seismic vulnerability assessment of the diverse categories of buildings found across building stocks requires specific methodologies that can capture the wide range of standards, regulations, construction practices, architectural layouts, earthquake design scenarios, and available knowledge. Previous vulnerability models have employed varying a...

The proposed research addresses the structural behavior of screwed connections in composite beams consisting of Cold-Formed Steel (CFS) profiles and timber boards. An experimental program consisting of 30 push-out tests involving six different models was conducted to evaluate the performance of different types of connection. The screw diameter and...

Mapping the structural responses based on main loads to characterize signature of complex structures with high-dimensional features is a determinant factor for structural health monitoring (SHM). Current technological advances contribute to the optimization of data analysis, aiming to make the process less demanding in terms of time and computation...

On April 3, 2024, a magnitude 7.4 earthquake, known as the 2024 Hualien Earthquake, struck offshore Hualien, Taiwan, at a depth of 15.5 km. Overall, the negative societal impacts were limited, despite varying levels of impact to the infrastructure, including power outages affecting over 308,000 households, landslides obstructing roads, bridge colla...

Flood risk is a pressing global concern, especially given its intensification by climate change. Likewise, events in the recent past have highlighted the need to implement adequate flood risk mitigation measures in cultural heritage. The effective mitigation of flood-related impacts to cultural heritage requires flood risk assessment to be based on...

This study explores potential differences in analytical fragility curves obtained when considering two alternative probabilistic demand models: one obtained using Multiple Stripe Analysis (MSA) and one obtained using Incremental Dynamic Analysis (IDA). When MSA is used, different groups of ground motions compatible with different Conditional Spectr...

The recent earthquake crisis in Turkey has brought forth crucial reflections that demand the attention of the scientific community. Within a day, two major earthquakes struck Turkey and Syria, with less than 10 hours between them, followed by numerous aftershocks. The events resulted in the collapse of numerous buildings during the initial earthqua...

Forecasting agricultural variables at national level is crucial for crafting policies aimed at ensuring food security and enhancing the stability of the entire agricultural food chain. However, this task is often daunting due to sparse data and the rarity of extensive records. This study seeks to assess the effectiveness of ten deep learning models...

The significance of dealing with multiple risks has become increasingly clear given the rising frequency of disasters caused by natural and man-made hazards impacting metropolitan areas. The current study focuses on an urban structural compound within the Lisbon Metropolitan Area (LMA) and the primary goal is to evaluate the vulnerability and risk...

Fragility curves are a fundamental component for developing risk and loss assessments of structures. This study explores potential differences found in analytical fragility curves obtained when considering two alternative analysis approaches: Multiple Stripe Analysis (MSA) and Incremental Dynamic Analysis (IDA), each associated with a different gro...

A new set of partial safety factors is proposed for the seismic safety assessment of existing reinforced concrete buildings. These safety factors are derived using a framework that focuses on the determination of the uncertainty in the limit state capacities. Existing seismic safety assessment standards, such as EN1998-3 or ASCE 41-17, follow a com...

On September 8, 2023, at 11:11 pm local time, a magnitude Mw 6.8 earthquake occurred in Morocco’s High Atlas mountain range, with a focal depth of 26 km. The earthquake was followed by several aftershocks, including a magnitude Mw 4.9 aftershock that occurred 19 minutes after the mainshock. The earthquake resulted in nearly 3,000 casualties and dam...

This study presents an overview of the design of reinforced concrete (RC) structures (moment frames, shear walls and large panels) for Romania and the impact on seismic exposure and vulnerability within the context of the recent European Seismic Risk Model 2020 (ESRM20). The overview is focused on the design of structural elements for bending momen...

A caducidade do modelo económico rural, o consequente abandono das atividades a ele associadas e a migração das correspondentes populações, levaram ao crescente acumular de carga combustível favorável ao desenvolvimento de incêndios rurais (IR). Adicionalmente, estudos recentes sobre as possíveis consequências das alterações climáticas mostram exis...

Current state-of-the-art analytical procedures for the seismic safety assessment of existing buildings account for various sources of uncertainty, of both deterministic and aleatory nature, with the most common being uncertainties related to the material properties, the building geometry, the detailing in RC elements, the input seismic action, etc....

This paper investigates the influence of manufacturing tolerances on the cyclic behavior of steel beams with European I‐shaped profiles. It also explores the applicability of machine learning methods in predicting this behavior. Previous research has focused on nominal sections, overlooking the effects of dimensional tolerances specified in the EN1...

The Sendai Framework for Disaster Risk Reduction (SFDRR) upholds the development and implementation of measures to reduce hazard exposure and vulnerability to disasters. Among other aspects, the SFDRR recognizes the importance of cultural heritage for society, thus emphasizing the need to assess the impact that potential hazards may have on the bui...

Flooding is among the natural hazards that cause the most significant damage to immovable and movable cultural heritage assets worldwide. Simplified flood vulnerability assessment methodologies are practical tools that can support decision-making strategies to address potential flood damage in cultural heritage assets. However, existing flood vulne...

“Twentieth-century building materials and construction techniques may often differ from traditional materials and methods of the past. There is a need to research and develop specific repair methods appropriate to unique types of construction.”Approaches for the Conservation of Twentieth-Century Architectural Heritage, Madrid Document 2011, ICOMOS....

This research focuses on the risk management of reinforced concrete heritage constructions in coastal environments, with an emphasis on preserving their cultural significance. It addresses a critical gap in existing risk-related research, since this type of heritage site is often overlooked in heritage conservation research. The proposed methodolog...

Monopiles are the Industry's first choice today to support an Offshore Wind Turbine (OWT) due to the complexities associated with fabrication, transportation, and installation of various foundation solutions. These are, however, considered suitable for water depths up to around 30 to 35 m, beyond which these become massive and complex to handle. In...

The Sendai Framework for Disaster Risk Reduction recognizes the importance of cultural heritage for society and emphasize the need to assess their vulnerability from multiple hazards. Developing adequate multi-hazard vulnerability assessment processes is fundamental to this end. Still, given the large number of cultural heritage assets that can be...

An Mw 7.8 earthquake occurred at a depth of 17.9 km and with epicenter coordinates 37.174°N 37.032°E near the city of Nurdağı in the Gaziantep province of Türkiye at about 4:17 AM local time on February 6, 2023. As a result of this sequence of earthquakes and aftershocks, around 28,500 buildings partially or completely collapsed, while another 66,0...

The presence of masonry infills is known to have a significant effect when assessing the seismic vulnerability of reinforced concrete (RC) structures, and including these elements in the numerical modelling has become imperative. In computationally-intense probabilistic analyses such as those integrated in performance-based earthquake engineering (...

The damage caused by seismic shaking and liquefaction-induced permanent ground deformation has conventionally been assessed as two separate problems often by different engineers. However, the two problems are inherently linked, since ground shaking causes lique-faction, and liquefaction-induced soil softening affects ground shaking. Modelling both...

Dam surveillance activities are based on observing the structural behaviour and interpreting the past behaviour supported by the knowledge of the main loads. For day-to-day activities, data-driven models are usually adopted. Most applications consider regression models for the analysis of horizontal displacements recorded in pendulums. Traditional...

The damage caused by seismic shaking and liquefaction-induced permanent ground deformation has conventionally been assessed as two separate problems often by different engineers. However, the two problems are inherently linked, since ground shaking causes liquefaction, and liquefaction-induced soil softening affects ground shaking.Modelling both pr...

The probabilistic seismic demand of selected engineering demand parameters obtained from three-dimensional analysis of RC buildings is analysed by examining their statistical distribution considering multiple angles of seismic incidence and various ground motion group sizes. Six probability distribution models are fitted to the engineering demand p...

A new European Seismic Risk Model (ESRM20) was recently released to the scientific community (http://risk.efehr.org). This model combines the European Seismic Hazard Model (ESHM20), a regional model of site response based on proxy data (topography and geology), an exposure model describing the distribution of building classes for 44 countries, and...

The buckling tendency of an offshore pipeline buried in a liquefiable soil aggravates under earthquake situations. Moreover, to understand the upheaval displacement behavior of an offshore pipeline under dynamic loading, it is crucial to understand the variation of liquefaction potential within the soil bed. Thus, in the present study, the variatio...

The article proposes a framework establishing a disaster resilience index applicable worldwide that accounts for differences between countries in terms of development and in terms of the relevance of several resilience dimensions. To achieve this index, countries were clustered using an indicator that reflected their performance according to the Su...

Seismic risk mitigation policies are a crucial step in the risk management of countries, such as those located in southern Europe. For this reason, the risk reduction measures associated to structural strengthening and retrofitting should be based on cost-benefit analysis of regional building stocks. This requires a full characterization of the sei...

Smart technologies such as artificial intelligence, the Internet of Things, and other cyber-physical systems are often associated to Industry 4.0 given their potential for transforming current manufacturing and industrial practices. In particular, the significant potential of these technologies for increasing automation, improving communication and...

The proposed study develops fragility functions for non-seismically designed reinforced concrete structures considering different pounding configurations. The study addresses an existing research gap, since large-scale seismic risk assessment studies involving the seismic performance assessment of building portfolios usually do not involve fragilit...

The proposed study examines the propagation of uncertainty associated with the angle of seismic incidence of a group of ground motions, as well as to that of the ground motion group size, to the expected seismic loss estimates of reinforced concrete buildings. Six buildings with infilled frame systems are studied, representative of non-seismically...

In real practice, to assess concrete strength in structures, engineers usually use non-destructive tests (NDT) (e.g. rebound hammer or ultrasonic pulse velocity) in addition to destructive tests (DT) that are carried out on cores extracted from the structure. The results of these tests (NDT and DT) are used to identify a relationship (a conversion...

This article introduces the Special Issue on Risk Protection for Cultural Heritage and Historic Centres. The article starts by reviewing the gaps in knowledge and practice related to disaster risk management of cultural heritage. It then reviews the contributions to the Special Issue, focussing on their multi-disciplinary findings that address some...

Extensive damage of the existing building stock and subsequent economical losses due to past earthquakes have urged researchers to focus their studies on the vulnerability quantification of the existing building stock as well as on ways to mitigate the expected losses in future seismic events. Among the loss assessment methodologies that have been...

In a changing world where the frequency of natural hazards is increasing, the consequences of disasters on cultural heritage assets are still not well understood. This can be attributed to shortcomings in existing risk management practices and to the fact that disaster consequences in the cultural sector are seldom recorded in a structured manner....

A magnitude 7.2 earthquake with epicenter coordinates 18.408°N 73.475°W and a depth of 10 km struck 13 km SSE of Petit Trou de Nippes in Haiti at approximately 8:29 am local time, affecting a wide swath of the Tiburon Peninsula, including the Departments of Nippes, Sud, and Grand’Anse. This earthquake resulted from an oblique reverse motion along t...

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 t...

Flooding is among the most common and damaging natural hazards at the global level, which has prompted governments and international institutions to adopt measures towards the reduction of flood risk. Among them is the development of flood risk assessments and flood risk management plans with a particular emphasis on cultural heritage, not only due...

This chapter provides additional information about the “identification of conversion model” step and the “strength estimation” step as defined in the flowchart summarizing the RILEM recommendation. The advantages and limits of the various options are illustrated by analyzing the results of synthetic simulations. Based on the developed synthetic dat...

Guidelines describe the general process of in-situ compressive strength assessment. This process is divided into three main steps, data collection (using nondestructive testing and destructive testing), model identification and strength assessment. Three estimation quality levels (EQL) are defined depending on the targeted accuracy of strength asse...

This chapter illustrates first how the recommendations proposed by RILEM TC 249-ISC can be applied in practice. All the steps of the investigation process described in the recommendations are followed and the obtained results are discussed. The second objective is to demonstrate the practical interest of some of the options promoted or recommended...

The concrete strength assessment process is influenced by uncertainties at many levels, including random measurement errors, sampling uncertainty and identification of the conversion model parameters. Therefore, instead of estimating the true value of the concrete strength, it is preferable to say that the objective of the assessment process is to...

This chapter aims to apply the recommendations of RILEM TC 249-ISC on a real structure, a four-level reinforced concrete framed structure. The flow chart describing the methodology proposed in the recommendations is applied and each stage is detailed. The proposed procedure is compared to the usual practices. The application of the new procedure pr...

This benchmark aims to assess mean compressive strength at several scales and to identify the location and characteristics of possible weak areas in the structure. It concerns synthetic data simulated on a group of four concrete cylindrical structures of identical dimensions with different kinds of strength distribution, based on a real case study....

Further analyses and results are presented and discussed in order to provide additional information and justifications regarding the efficiency of the investigation strategy proposed by the Recommendations and these guidelines. These additional results are obtained from an extensive simulation study based on the case study described in Chap. 8 that...

The main objective of test region (TR) identification is to define an efficient conversion model. The first part of the chapter aims a difficult question, the identification of test regions (TR) because each structure is specific and so it is impossible to give a unique methodology. Here, three different possibilities are proposed. The first one is...

When analyzing real data sets, observations different from the majority of the data are sometimes found. These observations are usually called outliers and can be defined as individual data values that are numerically distant from the rest of the sample, thus masking its probability distribution. Outliers require special attention because they can...

Indicator-based methods are able to provide a simple and reliable way to assess the level of fire risk of existing constructions. While many of these methods were not developed for cultural heritage assets, those that were often involve indicators connected to provisions defined by standards that are only valid in certain countries. As such, a meth...

The concrete strength assessment process is influenced by uncertainties at many levels, including random measurement errors, sampling uncertainty and identification of the conversion model parameters. Therefore, instead of estimating the true value of the concrete strength, it is preferable to say that the objective of the assessment process is to...

This benchmark aims to assess mean compressive strength at several scales and to identify the location and characteristics of possible weak areas in the structure. It concerns synthetic data simulated on a group of four concrete cylindrical structures of identical dimensions with different kinds of strength distribution, based on a real case study....

Guidelines describe the general process of in-situ compressive strength assessment. This process is divided into three main steps, data collection (using nondestructive testing and destructive testing), model identification and strength assessment. Three estimation quality levels (EQL) are defined depending on the targeted accuracy of strength asse...

The main objective of test region (TR) identification is to define an efficient conversion model. The first part of the chapter aims a difficult question, the identification of test regions (TR) because each structure is specific and so it is impossible to give a unique methodology. Here, three different possibilities are proposed. The first one is...

GIS is a powerful tool that can be used to achieve better management of fire risk prevention in built heritage. This research aimed to present a GIS-based workflow for the rapid and efficient identification of urban features and their processing for index-based fire risk evaluation in heritage buildings. The workflow shows the use and benefits of t...

Ao longo dos séculos, muitos foram os eventos destrutivos que assolaram a Região Autónoma da Madeira, destacando-se pelo impacto no território, as aluviões. Em consequência de uma intensa precipitação num curto espaço de tempo, cheias rápidas e deslizamentos em massas ocorreram um pouco por toda a Região, deixando, um elevado rastro de destruição....

The objectives of this PVRR are: 1) to provide details of the 30 October Mw 7.0 Aegean Sea earthquake, 2) to describe local codes and building practices, 3) to compare the recorded ground shaking with the values used for design, 4) to summarize the preliminary reports of damage to buildings and other infrastructure, including the disruption to the...

The proposed study analyses the performance of existing approaches to model the behaviour of partially infilled reinforced concrete (RC) frames for computationally-intense performance-based earthquake engineering applications. The study addresses the use of reduction factors that are applied to the strength and the stiffness of a fully infilled mas...

Estimating the extent of reinforced concrete (RC) frame components that may be damaged after an earthquake and the corresponding connection with the physical mechanisms that lead to damage accumulation is of the upmost importance when deciding retrofitting solutions, evaluating the potential repair cost or when selecting a nonlinear modelling techn...

In a global context of increasing flood risk, the development of risk assessments that can effectively support disaster risk management strategies and policies is crucial. This is particularly relevant in the case of cultural heritage, given its socioeconomic value. Although there is a substantial body of literature on the topics of cultural herita...

In-situ concrete strength assessment is commonly based on the implementation of Non-Destructive Tests (NDT) and coring of several specimens for Destructive Tests (DT). The most widely used non-destructive (ND) techniques are rebound hammer and ultrasonic pulse velocity. From the resulting data of NDT and compressive strength test results on specime...

The assessment of the vulnerability of buildings subjected to earthquake-induced liquefaction requires the definition of an integrated damage scale accounting both for ground motion damage and permanent ground movements. The latter can cause rigid-body settlements and tilt of the building, but also flexural demand on members due to the differential...

The accurate determination of demand during the seismic analysis of buildings requires that all factors having a significant contribution must be accounted for. The present study examines the effect of the angle of seismic incidence of earthquake ground motions on the inelastic demand of reinforced concrete buildings and defines its significance fo...

According to Eurocode 8, nonlinear time history analyses can be performed using a group of 7 ground motions, applied using only one angle of incidence (ASI). Under these conditions, the mean value of the response under consideration can be used to represent seismic demand. Since it is known that, the smaller the group of ground motions, the larger...

When evaluating the probabilistic seismic performance of a structure in the context of Performance-Based Earthquake Engineering (PBEE) applications, only estimates of the true response are obtained due to the finite size of the group of records selected to represent the seismic scenario. The proposed study examines the variability of these estimate...

Η παρούσα εργασία διερευνά την επιρροή της γωνίας πρόσπτωσης της σεισμικής δράσης κατά την αποτίμηση κτιρίων οπλισμένου σκυροδέματος και προτείνει τρόπους για την συνεκτίμησή της. Πιο συγκεκριμένα, επιλέγονται έξι κτίρια, τα οποία αναλύονται για σεισμική δράση εφαρμόζοντας τη μεθοδολογία που παρέχεται από το Pacific Earthquake Engineering Research...

The Sendai Framework for Disaster Risk Reduction (SFDRR) upholds the development and implementation of measures to reduce hazard exposure and vulnerability to disasters. Among other aspects, the SFDRR recognizes the importance of cultural heritage and its irreplaceable value for society, thus emphasizing the need to assess the impact that potential...

Despite the undeniable influence of the angle of seismic incidence on seismic demand, limited research has been performed to determine its effect when assessing the probabilistic seismic performance of a structure. Since the ground motion group size has a well‐known significant effect on the variability of collapse risk, the joint effect of both th...

This study describes the development of the various components of the European Seismic Risk Model 2020 (ESRM2020) which will be able to generate, using open-source software developed by the GEM Foundation (the

Recent events have demonstrated that earthquake-induced liquefaction can result in significant structural damage and human casualties. The consideration of soil liquefaction has primarily been the domain of geotechnical engineering; however, recent studies have shown a strong interaction between liquefaction-development and the superstructure loads...

The paper discusses the overall effect of the angle of seismic incidence during the seismic safety assessment of reinforced concrete buildings employing state-of-the-art methods of analysis, and provides proposals on how to account for this effect. Particularly, the Performance Based Earthquake Engineering (PBEE) methodology developed by the Pacifi...

A intervenção em património cultural reveste-se de particular responsabilidade pois está-se perante uma herança cultural que se pretende passar às gerações vindouras mantendo os critérios de integridade e autenticidade. Em ações de requalificação ou de reabilitação é possível a manutenção das estruturas portantes existentes como paredes, pavimentos...

This article presents a methodology to assess the reliability of dynamic scour protections used to protect offshore wind turbine foundations. The computed probabilities of failure are based on a dataset of 124 months of hindcast data from the Horns Rev 3 offshore wind farm. Copula-based models are used to obtain the joint distribution function of t...

Masonry-infilled reinforced concrete (RC) frames are a widely adopted building system. Although usually disregarded in design, masonry infills are known to affect the behavior of structures under earthquake loading. Adequate numerical models are therefore required to perform realistic analyses of their behavior under earthquakes. In this context, m...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance tes...

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = .05 to .005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance tes...

Probabilistic analysis allows taking into account uncertainties that deterministic approaches usually don't permit. In this context, the uncertainty of the angle of seismic incidence is addressed and its effect on the seismic demand of buildings is examined in a probabilistic framework. Buildings comprising different configurations in-plan and in-e...