Structural Vulnerability Research Articles

A Dual-Layer Complex Network-Based Quantitative Flood Vulnerability Assessment Method of Transportation Systems

Evaluating the vulnerability of urban transportation systems to flood disasters can provide scientific support for urban disaster prevention and mitigation. Current methods for assessing the flood vulnerability of urban roads often overlook the internal relationships within the complex spatial composition of road networks and surface structures. In this study, based on the theory of complex networks, a dual-layer network assessment model is established for evaluating the flood vulnerability of urban transportation systems by coupling basic geographic data with road network vector data. Unlike traditional methods, this model considers the complex relationship between road network structures and ground surfaces, uncovering a correlation between road network structure and road flood vulnerability. By utilizing this model, the flood vulnerability of road networks in Shenzhen, as well as the city’s spatial flood vulnerability, are quantitatively assessed. Based on the quantitative results, we create maps illustrating the distribution of road and spatial flood vulnerability in Shenzhen. The study results reflect that roads highly vulnerable to flooding are mainly located in the central urban area of the southwest, with the flood vulnerability spatially concentrated primarily in the northern and western regions. Using data from government reports, news stories, and other sources over the past five years, we compile recorded instances of urban waterlogging. The quantitative results of the model are consistent with the distribution trend in recorded waterlogging points, indicating that the model’s outcomes are authentic and reliable.

EFFECTIVE POSITION OF SHEAR WALL FOR HIGHER RISE FOR TIME HISTORY ANALYSIS

The abstract of the study that is titled "Effective Position of Shear Wall for Higher Rise for Time History Analysis" focuses on the investigation of the best placement of shear walls in tall buildings in order to improve the seismic performance of these buildings via the use of time history analysis. By doing this research, the researchers hope to find a solution to the essential problem of establishing the most effective location of shear walls in high-rise structures in order to reduce the effects of seismic forces. Evaluating the dynamic response of tall buildings under earthquake loading circumstances is the purpose of this work. This evaluation is accomplished through the utilisation of sophisticated numerical simulations and time history analytic methodologies. In order to conduct a full analysis of the structural behaviour, the investigation takes into account a number of parameters, including the height of the building, the configuration of the shear wall, and the seismic intensity. Additionally, the study analyses the influence of varied shear wall placements on key performance measures including base shear, story drift, and acceleration responses. The purpose of this research is to determine the ideal position and configuration of shear walls for higher buildings by means of systematic analysis and comparison of the results. This will help to reduce the structural vulnerability of the building and increase its seismic resilience. Those structural engineers and designers who are involved in the seismic design of high-rise structures will find the findings of this study to have significant implications. These findings provide valuable insights into effective strategies for improving the earthquake resistance of tall buildings through optimized shear wall placement. Keywords: Shear walls, High-rise buildings, Seismic analysis, Time history analysis, Structural optimization, Finite element analysis, Seismic performance, Building dynamics, Structural stability, Optimal placement.

Collapse analysis and robustness assessment of dropped-story steel frame structures based on structural vulnerability theory

ABSTRACT This paper proposes an improved analysis method based on the theory of structural vulnerability, which incorporates structural redundancy and comprehensively analyzes structural vulnerability and robustness by considering the changes in structural stiffness and redundancy after damage to structural members under conventional loading. The improved method takes into account the changes in the strain energy of the structure after the damage of the structural members, which can be more in line with the actual situation of continuity collapse, and solves the complex process of traditional structural vulnerability theory that requires clustering and unclustering, greatly reducing the workload as well as solving the problem of not being able to find the critical members of the structure. The improved method is used to analyze the vulnerability of a 5-story dropped-story steel frame structure, to find the critical members of the structure based on the test data simulated by ABAQUS, to evaluate the robustness, and to propose improvement measures. The results show that the improved vulnerability assessment method is more reasonable and effective and can be applied to different steel frame structures.

Exploring minimal indirect digital economy taxation as a post-COVID-19 economic recovery strategy for African revenue mobilisation

The COVID-19 pandemic and its aftermath continue to devastate most areas of society and continue to reveal inherent structural vulnerabilities in the economies, social, and health systems in countries. In addition, the Russia-Ukraine conflict of 2022 and the geopolitics of its resolution continue to create shocks across the globe- evidenced by rising inflation, increased sovereign debt level, recession, and reduced public expenditure among others. While many sectors of the economy were crippled by the back-to-back global economic shocks of the Covid-19 pandemic and the Russia-Ukraine conflict through reduced economic activities resulting in a global recession and reduced tax revenues for public expenditure, the digital economy has surprisingly boomed and continues to grow in this period of uncertainty. This has been directly attributed to the 'lure of the alternative', caused by the social and economic lockdowns imposed by countries, which pushed many persons and companies to explore the next available option- online platforms to conduct business. Although the rise in the use of digital platforms for business activities is commendable, this development has some implications for traditional business frameworks which in turn affects revenue mobilisation for funding public infrastructure projects and services. This is because, in Africa, the digital economy is not as well-regulated as the traditional economy. This creates an avenue for tax evasion and avoidance, arising from the dynamic and complex nature of digital transactions. This challenge requires that urgent solutions be found for the effective taxation of the digital economy. There will be a need to review/reform economic and fiscal policies and laws to ensure a faster recovery from the economic effects of the COVID-19 pandemic. There would also be a need to create digital tax policies that are equitable for source and market jurisdictions and, lastly, there will be a need for cooperation in tax law and policies across Africa that capture the reality of the growth and ubiquitous presence of digital multinationals in Africa.

Post Fire Assessment of RCC Buildings Through Rapid Visual Screening

The effectiveness of rapid visual screening (RVS) in determining the fire risk of reinforced concrete (RCC) buildings is examined in this review. RVS provides a quick and practical approach to evaluate fire risks, addressing the shortcomings of traditional methods. Through a comprehensive examination of methodology, advantages, limitations, and future directions, this study aims to enhance understanding and application of RVS in fire assessment. The study employs a systematic approach to evaluate the effectiveness of RVS, analyzing its application in assessing fire vulnerability in RCC structures. Key aspects of RVS methodology, including visual inspection, identification of structural vulnerabilities, and categorization of damage, scrutinized. A case study of the Chopasani Housing Boards building in Jodhpur provides empirical evidence of RVS's utility in identifying fire-related structural vulnerabilities. The concluded, the analysis reveals that RVS effectively categorizes fire-induced damage in RCC buildings, facilitating prioritization of mitigation efforts. Damage classifications, ranging from mild to extreme, are discerned through RVS, underscoring its ability to swiftly assess structural vulnerabilities. Additionally, RVS analysis elucidates the residual strength of RCC components post-incident, providing valuable insights for retrofitting and maintenance efforts. Overall, this study highlights the pivotal role of RVS in bolstering structural fire safety measures, emphasizing its practicality, cost-effectiveness, and accessibility. However, limitations such as subjectivity and inadequate assessment of complex structures necessitate ongoing refinement and integration with advanced technologies. The findings underscore the importance of RVS in enhancing fire safety assessment practices and mitigating fire risks in urban buildings, particularly in the context of reinforced concrete structures.

The Spatial Scale and Spread of Child Victimization.

Previous research shows that large, densely populated urban areas have higher rates of child victimization that have persisted over time. However, few investigations have inquired about the processes that produce and sustain hot and cold spots of child victimization. As a result, the mechanisms that produce the observed spatial clustering of child victimization, and hence "why" harms against children tend to cluster in space, remains unknown. Does the likelihood of being a victim of violence in one location depend on a similar event happening in a nearby location within a specified timeframe? Rather, are child victims of violence more likely to reside in suboptimal neighborhood conditions? This paper aims to present an analytical and theoretical framework for distinguishing between these locational (point) processes to determine whether the empirical spatial patterns undergirding child victimization are more reflective of the "spread" via contagion (i.e., dependency) or whether they are produced by neighborhood structural inequality resulting from spatial heterogeneity. To detect spatial dependence, we applied the inhomogeneous K-function to Los Angeles Medical Examiner data on child homicide victim locations while controlling for regional differences in victimization events (i.e., heterogeneity). Our analysis found strong evidence of spatial clustering in child victimization at small spatial scales but inhibition at larger scales. We further found limited support for the spatiotemporal clustering of child victimization indicative of a contagion effect. Overall, our results support the role of neighborhood structural vulnerability in the underlying mechanisms producing patterns of child victimization across Los Angeles County. We conclude by discussing the policy implications for understanding this spatial patterning in geographical context and for developing effective and targeted preventive interventions.

The embodiment of exclusionary displacement pressure: Intersections of housing insecurity and mental health in a Hispanic/Latinx immigrant neighborhood

Gentrification, growing income inequality, urban development, and the affordable housing crisis necessitate understanding the impact of the concern of displacement on health — prior to or even in the absence of a displacement event. In this paper, I use the term “exclusionary displacement pressure” to unify the literature on exclusionary displacement and displacement pressure, highlighting the disproportionate and inequitable impacts of displacement pressure among communities of color. Through following 35 residents over 2.5-years (2019–2022) in one predominantly low-income Hispanic/Latinx immigrant neighborhood in Denver, Colorado, I examine how exclusionary displacement pressure shapes their health and wellbeing over time. Through paying attention to how participants' lived experience is shaped by structural vulnerability (e.g. lack of documentation status, inadequate work, limited access to safety net systems), I identify how exclusionary displacement pressure is constantly internalized and responded to as a unique embodied health experience, wearing on individuals over time and reproducing population health inequities. The framework of embodied health experiences captures the wide range of health-related impacts, from diagnosable health conditions to idioms of distress, using participant's own language of suffering to express how they were feeling, battling, and enduring the pressure. Theorizing on structural vulnerability within specific subpopulations with intersecting identities, such as low-income immigrant Hispanic/Latinx communities, provides a bottom-up refinement to existing theories of embodied health. Understanding the place-health experiences of individuals in changing neighborhoods over time is also critically important to define time points at which context-specific supports and interventions are appropriate.

Natural fiber-based multifunctional aerogel with advanced oil absorption property and high thermal insulation performance

Designing an ultra-light and controllable structure for multifunctionality of low-cost aerogels is of great significance but remains a huge challenge because of the limitations of structural processability and mechanical vulnerability. Herein, we demonstrated a facile approach to synthesize a low-cost, ultralight, elastic, and highly recyclable superabsorbent from renewable fibers via environmentally friendly physical bonding and freeze-drying. Our approach introduces skin-core structure polyester (SPFs) into natural agriculture plant kapok, through which fibers entanglement and bonding to construct aerogel with adjustable hierarchical structure and desirable shapes. The resultant composite aerogel can be easily modified by organosilane, demonstrating durable superhydrophobicity (158.5°), advanced absorption capacity (128.4 g/g), good mechanical performance, self-cleaning, and thermal insulating (0.020 W/(m·K)). Therefore, the sustainable and multifunctional composite fibrous porous aerogels are potential materials for oil absorption applications and thermal management.

The impact of Covid‐19 on banking groups’ balance sheets in the euro area

AbstractMost studies have found that the Covid‐19 pandemic did not negatively impact the euro area banking industry's performance at an aggregate level. This study explores whether this finding still holds using the return on assets of 16 banking groups operating in the euro area and considering bank‐specific factors, idiosyncrasies related to different exposures of their portfolios to the business cycle and weaknesses stemming from underlying structural vulnerabilities. The banking groups are classified into clusters using unsupervised learning techniques. This research contributes to the empirical literature on the determinants of banks’ performance by highlighting the importance of banks’ heterogeneity, notably controlling for differential performance due to asset quality, solvency and business model. In addition, this paper shows that the magnitude of return on assets’ exposure to the business cycle varies across banks and that inflation in the euro area matters only for a subset of them. Importantly, the study sheds some light on the possible reasons for the mixed results in the literature regarding the role of non‐interest income, the T1 capital ratio and inflation. Finally, no significant effects of the Covid‐19 variables on banks’ return on assets are found during the first seven quarters of the pandemic.

Terrestrial Laser Scanning (TLS) Survey and Building Information Modeling (BIM) of The Edmund Pettus Bridge: A Case Study

Abstract. The comprehensive digital documentation of the Edmund Pettus Bridge, a symbol of the American Civil Rights Movement located in Selma, Alabama, serves as an example of integrating Terrestrial Laser Scanning (TLS) and Building Information Modeling (BIM) technologies for the conservation of heritage infrastructure. This study aimed to employ advanced TLS and other Reality Capture (RC) techniques to generate a high-resolution, three-dimensional representation of the bridge, thereby aiding in its structural assessment and preservation. Utilizing TLS alongside 360-degree photography and UAV surveys, the project achieved detailed coverage of the bridge's architectural and structural features. The data collected was processed into a BIM model using Autodesk Revit, offering comprehensive analysis and preservation planning. The findings from this research highlighted previously undetected areas of material degradation and structural vulnerabilities, emphasizing the value of TLS and BIM in revealing critical insights into the condition of heritage structures. This project preserved the digital memory of an iconic Civil Rights landmark and set a framework for applying digital documentation technologies in heritage infrastructure conservation. The success of this methodology offers a valuable precedent for future conservation efforts, showcasing how RC technologies can enhance the preservation of historical sites and ensure their legacy is maintained for future generations.

Affordable Sensors for Speditive and Accurate Documentation of Built Heritage: First Tests and Preliminary Results

Abstract. When facing unregulated human interventions, the tumultuous backdrop of wars, and the relentless impact of climate change, a significant effect is held on those structures that stand as custodians of our cultural identity and historical legacy. The need to document their status is an essential first step toward preservation and restoration. This contribution will analyze and compare diverse datasets acquired through three distinct methods: Terrestrial Laser Scanner, Apple’s iPhone 15 Pro with no additional tool, and iPhone 15 Pro using Pix4D viDoc RTK Rover to assess the quality and accuracy of point clouds, as well as to determine the feasibility of each technique for the expeditious documentation of endangered built heritage. The use of mass-distributed low-cost sensors provides a rapid and cost-effective means to capture detailed 3D models of built heritage while, at the same time, democratizing the process of documentation. Low-cost sensors not only facilitate documentation but also enhance the efficiency of conservation efforts. The precision of LiDAR sensors helps identify structural vulnerabilities, allowing conservationists to prioritize interventions and allocate resources wisely. Furthermore, detailed imagery will enable conservationists to monitor subtle structural changes over time, acting as an early warning system against potential threats. As an additional aid, the RTK Rover enables centimeter-level positioning accuracy while maintaining a compact and fast deployable design, and the direct measurement of Ground Control Points (GCPs) significantly streamlines the surveying process and equipment footprint.

Innovative control strategy for flood mitigation through a combination of barrage management on impounded rivers and polders

The partially catastrophic effects of large floods, such as the events of 2002 and 2013 in Germany and Austria for example, clearly show the vulnerability of settlement structures along large rivers. In the case of impounded rivers with run-of-river hydropower plants, the main question is whether a reduction of floods can be achieved with flood-adapted, intelligent control of barrages - to date, the operational objective has been the safe discharge of floodwater; targeted reduction is currently an unoccupied field due to its complexity. Specifically, the interaction with the operation of a polder for flood retention is of special interest, as polders are a much-discussed and effective element of flood protection, especially at higher discharges, that directly influences the hydrograph shape. Extensive analyses and sensitivity investigations of a multitude of parameters and measured values, using a complex model system, are needed in order to investigate the reduction potential of the named technical flood protection measures and the development of control strategies relevant to practice. It is essential to base the developed controlling strategies on operationally available data, as this is the only way to make the determined reductions relevant for practical operation.

Failure Behavior and Vulnerability of Containment Structures Subjected to Overpressure Loads Considering Different Failure Criteria

This paper investigates the failure behavior and vulnerability of the containment structure (CS) under internal pressure according to different functional and structural failure criteria. Through nonlinear numerical analysis, the deformation of the structure, degree of concrete cracking, and the distribution of stresses and strains in the prestressing tendons and steel liner under different failure criteria are compared. Combined with probabilistic analysis methods, the vulnerability curves, HCLPF capacities, and total failure probabilities of CS determined by different failure criteria are systematically discussed. Results show that there are some differences in the failure behavior and pressure capacity of CS under different failure criteria for both functional and structural failure modes. Under the same failure mode, the variability of the pressure capacities obtained using different criteria is relatively small. Generally, the total failure probabilities of CS subjected to overpressure loads determined by different failure criteria exhibit significant differences. If it is considered that all the investigated failure criteria have a certain ability to predict containment failure, the probabilistic assessment results derived from the functional failure criterion based on the fracture strain of steel liners and the structural failure criterion based on the global strain are deemed to be more reasonable.

Curved Polymeric Sandwich Composites Subjected to Air Shock: An Experimental Investigation

BackgroundThe vulnerability of polymeric composite sandwich structures in marine applications to air explosions highlights a significant gap in our understanding of the dynamic behavior of the curved sandwich structures, which is essential for design improvements.ObjectiveThis study aims to explore the dynamic response and failure mechanisms of curved sandwich composite panels subjected to air-blast loading, providing insights into their structural integrity under such conditions.MethodsExperiments were performed using laboratory-simulated air shocks generated by a shock tube, employing high-speed photography and digital image correlation to measure deflections on the back surface of the panels. The panels, made with PVC closed-cell foam cores of two densities (H45 and H130), were tested across three curved geometries (radii of 112 mm, 305 mm, and infinity) under various boundary conditions.ResultsFindings indicate an increase in deformation with a decreased radius of curvature under simple support conditions, a trend that reverses under arrested displacement conditions. Moreover, a reduced radius significantly enhances panel strength and resistance to interfacial damage, with the primary failure mode transitioning from core shear cracking to interfacial debonding as core density increases.ConclusionsThe study reveals that the radius of curvature, boundary conditions, and core density significantly affect curved sandwich panels’ dynamic response and performance. Panels with smaller radii and higher core densities exhibit increased strength, though boundary conditions introduce variable effects on deformation behavior.

IMPLEMENTATION OF THE PRISM SURVEY FORM TO CREATE SEISMIC RISK MAPS

This study details a seismic risk assessment of stone and adobe masonry structures in the Agios Dometios Municipality, Nicosia, Cyprus. The study integrates field inspections using the PRISM survey form, designed exclusively for masonry buildings, with advanced analytical procedures. The initial phase involves comprehensive field inspections to evaluate the structural condition and vulnerabilities of these historic masonry buildings. The data gathered from these inspections provide essential insights into potential seismic risks. This data, alongside fragility curves generated from 3D finite element (FE) models using nonlinear time-history analysis, informs the creation of seismic risk maps for Agios Dometios. These maps offer a comprehensive depiction of the area's seismic vulnerability, particularly concerning the masonry structures, serving as invaluable resources for local authorities and conservationists in strategizing preservation and reinforcement measures, and in formulating mitigation plans. This study's approach, blending field inspections with advanced computational analysis, provides a robust framework for assessing the seismic risks of masonry structures. It holds significant implications for preserving architectural heritage in seismically active regions, offering a model that can be replicated in similar urban contexts.

IMPLEMENTATION OF THE PRISM SURVEY FORM TO CREATE SEISMIC RISK MAPS

This study details a seismic risk assessment of stone and adobe masonry structures in the Agios Dometios Municipality, Nicosia, Cyprus. The study integrates field inspections using the PRISM survey form, designed exclusively for masonry buildings, with advanced analytical procedures. The initial phase involves comprehensive field inspections to evaluate the structural condition and vulnerabilities of these historic masonry buildings. The data gathered from these inspections provide essential insights into potential seismic risks. This data, alongside fragility curves generated from 3D finite element (FE) models using nonlinear time-history analysis, informs the creation of seismic risk maps for Agios Dometios. These maps offer a comprehensive depiction of the area's seismic vulnerability, particularly concerning the masonry structures, serving as invaluable resources for local authorities and conservationists in strategizing preservation and reinforcement measures, and in formulating mitigation plans. This study's approach, blending field inspections with advanced computational analysis, provides a robust framework for assessing the seismic risks of masonry structures. It holds significant implications for preserving architectural heritage in seismically active regions, offering a model that can be replicated in similar urban contexts.

Bringing the state back in: Ruling parties and regime collapse during the Arab Uprisings

Scholars have mostly investigated the fall of dictatorships during the Arab Uprisings through the lens of contentious politics, uncovering new information about the protest dynamics and how they spread both within countries and throughout the wider region. However, the longer structural vulnerabilities within regimes have received little attention; yet such factors internal to states and their regimes proved paramount to the social revolutions investigated by Theda Skocpol. Focusing on the case of Tunisia, the author shows how the economic downturn and a succession crisis contributed to the decay of the Zine el-Abidine Ben Ali regime starting in the 2000s. Importantly, they heightened internecine conflicts within the regime and, in particular, within the longtime ruling party, the Constitutional Democratic Rally. It is through this backdrop that the events of the 2010–2011 Tunisian revolution must be understood: far from supporting the regime in times of crisis, members of Ben Ali’s ruling party engaged in contentious activities against him, thus crucially weakening the regime from within.

Mapping the Flood Vulnerability of Residential Structures: Cases from The Netherlands, Puerto Rico, and the United States

Mapping the Flood Vulnerability of Residential Structures: Cases from The Netherlands, Puerto Rico, and the United States

'Everywhere I call, there's nothing available': Understanding the alcohol treatment landscape and needs among unstably housed people who use alcohol in Rhode Island.

Alcohol is a leading cause of morbidity and mortality in the United States and people who are unstably housed are disproportionately impacted by adverse alcohol-related health outcomes. Addressing the needs of unstably housed people with high-intensity alcohol use (i.e., heavy episodic use or binge drinking), including those whose goal is not abstinence, is critical to reducing harms among this population. This study explores the alcohol-related treatment and support needs among unstably housed people who use alcohol. Data collection included participant observation and semi-structured interviews (n = 25) with unstably housed people with high-intensity alcohol use. Data were analysed thematically, with attention to structural vulnerability and social-structural forces at shaping perceptions of and experiences with alcohol treatment. Participants underscored how housing instability was critical in precipitating and maintaining heavy alcohol use, with alcohol often used to manage the stress and anxiety related to housing instability. While participants regularly engaged with alcohol treatment programs, program design and barriers to access undermined the effectiveness of these services for participants. Participants described the need for a range of program and service options across a continuum of care to be implemented to support participants in meeting their diverse needs and identified goals regarding alcohol use. Alcohol treatment and supports need to be modified so that they include a range of harm reduction and abstinence-based models to better meet people's diverse needs. Furthermore, treatment must be paired with permanent and affordable housing to address underlying drivers of alcohol-related harm for unstably housed people.

Seismic performance assessment of a low-rise thin reinforced concrete wall building with unconnected fiber reinforced elastomeric isolators using real-time hybrid simulations

Thin reinforced concrete wall (TRCW) buildings have become one of the most cost-effective and fastest options for housing construction. However, the performance of the TRCW building under seismic loads has limited energy dissipation capacity and is characterized by brittle failures with dimensions below those limited in international standards, which classifies these walls as ultra-thin. By contrast, unconnected fiber-reinforced elastomeric isolator (U-FREI) devices are a type of seismic isolators with a high deformation capacity, low-cost development, and simplified manufacturing and installation process. To leverage the advantages of both mentioned systems in a combined manner and reduce the structural vulnerability of this type of buildings, this study presents an evaluation of the seismic performance of unconnected fiber-reinforced elastomeric isolator (U-FREI) devices as a base isolation system for low-rise thin reinforced concrete wall (TRCW) buildings using real-time hybrid simulations (RTHS) as an innovative testing technique. RTHS, as a novel physical cybernetic testing technique, allows a dynamic system of interest to be sub-structured into two components: numerical and experimental. The numerical substructure used in this study corresponds to a 24 degrees of freedom (DOF) model that represents the dynamic behavior of a reference low-rise TRCW building. Moreover, the experimental substructure consisted of scaled U-FREI devices that replicated the dynamic response of the base isolation system of the building. To develop an interface between the two substructures, a horizontal transfer system (HTS) was implemented and coupled with a vertical transfer system (VTS). Using RTHS, the performance of the isolated TRCW building was evaluated under four seismic events: El Centro, Kobe, Loma Prieta, and Morgan, at a maximum acceleration of 0.70 g (6.87 m∙s−2). The implementation of U-FREI devices as base isolation system in a low-rise TRCW building allowed a reduction of the maximum drift by over 54.80 % in comparison with the fixed structure. Finally, the U-FREI devices seismic performance is discussed.