Historical Structures Research Articles

The strengthening of the 130-year-old San Michele bridge in Paderno d’Adda, Italy – an experience between past and present

The San Michele Bridge in Paderno, Italy, is a prime example of the refurbishment of a historic structure. An architectural and historical landmark, it is the last of a remarkable group of trussed arch bridges built in the late XIX century to be fully operational, and serves the Seregno-Bergamo railway line and the provincial road SP54/166 connecting Paderno d‘Adda and Calusco. In 2014, after 130 years of service, the bridge was subjected to an extensive survey and inspection campaign to acquire a more profound knowledge of the structure and its reliability. Overall, the inspections revealed that the bridge was still in a decent state but needed refurbishment. This article will briefly present the challenges faced in the design and execution of the refurbishment works.

Preconditions influencing the development of post-secondary training programs in universities for individuals with intellectual disabilities

ABSTRACT Background Research on post-secondary training for individuals with intellectual disabilities has generally focused on programs, with little consideration of the structures and mechanisms that give rise to them. This article adopts a critical realist perspective to comparatively analyse and theorise about the contextual structures contributing to the introduction of post-secondary training programs in universities for individuals with intellectual disabilities. Method Six stages in critical realist explanatory research were followed. They include (1) description, (2) analytical resolution, (3) abduction/theoretical redescription, (4) retroduction, (5) comparison between different theories and abstractions, and (6) concretisation and contextualisation. Results Historical, socio-political, and educational policy structures and mechanisms, indicated three program typologies: program as niche, as a generalisable prototype, and as an evolutionary response to evolving conditions. Conclusions By developing explanations about preconditions, the study draws out nuanced sub-types occurring within a single university-based program, theorises on trajectories for success, and lays the groundwork for future empirical and conceptual development.

Solid Surf

Skateboarding is an important part of 21st century culture and has considerable cultural, financial and entertainment value, as indicated by its recent incorporation in the Tokyo Olympics. It is practiced on human-made surfaces such as pavements and roads as well as on wooden ramps and within asphalt and concrete skateparks. Hundreds of examples of the latter were built worldwide during the skateboarding’s ‘Second Wave’ in the late 1970s–early 1980s, but nearly all were subsequently closed, infilled or destroyed. Very few original concrete parks of this key period survive and many are currently threatened with destruction. The historic status recently ascribed to two well preserved examples in the UK and Australia underlines a need to assess the heritage value of the other remaining original skateparks, as well as to consider possible strategies for their protection and conservation. The present article tackles this topic using selected examples of these unconventional historic structures from around the world.

Behavior of grout injected solid stone masonry walls under in-plane loading

It is a shared duty of all humanity to ensure the preservation of historical structures for future generations. The discontinuities, cracks, and gaps in the masonry walls, especially in historical structures, prevent the building from working monolithically. For this reason, historical buildings need repair and strengthening efforts in time. Grouting is an effective technique for consolidating and strengthening masonry structures. This study aims to establish a general evaluation of the injection method used to repair damaged stone walls. For this purpose, solid stone masonry walls were constructed and tested under in-plane loading to simulate the actual conditions. The solid stone masonry walls are made of saw-cut travertine stones and plastered with English bond, a pattern formed by laying alternate courses of stretchers and headers. The mechanical behavior of the solid stone masonry walls, both in non-damaged condition and with grout injected into the cracks caused by the preloading, was monitored and demonstrated in terms of the load-displacement relationship. As a result of the wall tests, it was observed that there was an increase of up to 28% in the maximum lateral load that the walls can withstand without any crack formation after grout injection.

Long‐term patterns of fish community structure and decline in native species in a Colorado River reservoir, Arizona and Nevada

AbstractObjectiveThe Colorado River has undergone substantial anthropogenic modifications, and a suite of nonnative species have been introduced since the 1800s; consequently, native fish communities are severely imperiled. We examined temporal patterns in fish community structure in Lake Mohave (i.e., lower Colorado River basin) over 40 years from 1980 to 2020.MethodsWe examined long‐term abundance and richness trends and the trajectory of fish community structure in multivariate space to assess stability and turnover using results from biannual (spring and autumn) trammel‐net monitoring over 40 years from 1980 to 2020.ResultNonnative fishes were established prior to sampling, precluding the ability to determine historical fish community structure. Bonytail Gila elegans and Razorback Sucker Xyrauchen texanus were the only two remaining native fishes, and both declined precipitously in abundance through time. However, a repatriation program initiated in 1991 prevented Razorback Sucker from extirpation, while reintroduction efforts for Bonytail have failed. Both wild populations are gone. Total catch per unit effort showed a negative relationship from 1980 to 2020, whereas total species richness showed no relationship. Long‐term abundance trends at the species level indicated three nonnative species (i.e., Gizzard Shad Dorosoma cepedianum, Yellow Bullhead Ameiurus natalis, and Smallmouth Bass Micropterus dolomieu) increased, nine decreased, and three showed no relationship. Fish community composition exhibited low stability and moderate turnover and shifted directionally through time in multivariate space, with the formation of three clusters, possibly indicating alternative states.ConclusionThe contemporary fish community shows little resemblance to the endemic ichthyofauna that has historically occupied the Colorado River, and the Razorback Sucker is the only remaining native species due to recovery efforts. Continued adaptive management will be required to preserve the most genetically diverse Razorback Sucker population in the Colorado River system, especially while coexisting with an unstable nonnative fish community.

GREEN INFRASTRUCTURE FOR PROTECTING SHIRAZ'S HISTORIC URBAN FABRIC FROM FLOODING

Shiraz, a city known for its rich historical urban fabric, faces increasing challenges posed by climate change and extreme weather events, particularly floods. The rapid urbanization and limited stormwater management infrastructure have exacerbated the vulnerability of the city's historic areas to flooding. Due to the registration of 360 km of Shiraz historical fabric in the national register in 2023, the importance of planning to safeguard this precious heritage has become twice as crucial. This study explores the potential of urban green spaces as a sustainable approach to mitigate flood impacts on Shiraz's historic urban fabric. Through a comprehensive analysis of flood patterns, urban green spaces, and historic buildings, this research aims to identify the most flood-prone areas and assess the effectiveness of existing green spaces in minimizing flood risks. The study also evaluates the role of vegetation and permeable surfaces in stormwater management to reduce floodwater runoff and its impact on historical structures. The findings reveal that strategically designed and maintained urban green spaces can act as natural flood buffers, helping to regulate water flow, reduce surface runoff, and minimize flood-induced damage to historic buildings. By integrating green spaces into urban planning, policymakers can enhance the city's resilience to floods and preserve the unique character and heritage of Shiraz's historic urban fabric. This study advocates for incorporating green infrastructure and sustainable stormwater management practices as integral to urban planning strategies. By embracing nature-based solutions, Shiraz can safeguard its historical treasures and foster a more sustainable and resilient urban environment for current and future generations. This research aimed to assess the implications of reducing urban green spaces, particularly in the green belt surrounding Shiraz's historic urban fabric and Snag-e-Siah neighborhood, on the vulnerability of historical sites to flood damage and potential demolition. With the utilization of urban green spaces, flood damage to Shiraz's built heritage was investigated in this study using both quantitative and qualitative methods simultaneously. The study results showed that the reduction of urban green infrastructure significantly increased the damage caused by floods in the historical area of Shiraz.

Proof of Concept for Methodological Framework Including Point Clouds in the Non-Destructive Diagnosis of Historical Masonry Structures

ABSTRACT The diagnosis of cultural heritage structures is a challenging and delicate task. It involves the evaluation of potential pathological situations, the understanding of the origin of displacements and deformations, and the assessment of the state of conservation of building materials. Destructive and minor destructive techniques are mostly prevented from being used in the context of historical constructions and the complementary use of non-destructive techniques is often the only viable solution. This paper addresses the possibility of employing point clouds, widely used for representation aims, as a source of information to identify the deterioration patterns that can affect construction safety. The proposed methodology includes two approaches following a perspective based on simple and recurring elements that form the complex and unique shape of historical buildings. The geometry of structural elements guides the choice towards the computation either of the Z-coordinate of each point of the cloud or the Euclidean distance between the point cloud and an elementary non-deformed geometry fitted to it. By investigating several case studies and diverse deterioration patterns, the proposal establishes a framework to employ point clouds, together with other techniques, as an effective tool to support the diagnosis of heritage structures.

Acoustical characterization of historical performance structure of Taramati Baradari at Hyderabad, India

The Baradari, a square-shaped building with twelve open doors, was designed for entertainment purposes and featured outstanding acoustic qualities, making it ideal for music and dance performances by noble courtesans. This article focuses on the acoustic characterization of Taramati Baradari, a historical performance structure in Hyderabad, India, built during the 17th century by the Qutb Shahi (Golconda) dynasty. The research aimed to assess the space's acoustical behaviour through in-situ measurements in an unoccupied state. Virtual acoustical models were developed and validated using the in situ measurements in the same condition, later simulated and analysed for both occupied and unoccupied scenarios, revealing an average reverberation time (RT60) of 4.1 s at mid-frequencies for unoccupied conditions. After analysing various acoustical parameters, it became evident that Taramati Baradari's acoustics possessed a distinctive character, giving the structure a unique identity. Unfortunately, in the Indian context, conservation and restoration efforts have primarily focused on visual aspects, often neglecting considerations of the space's acoustics. Therefore, characterizing the acoustic nature of performance structures becomes vital to inform sustainable interventions for conservation architects.

Rapid changes in age structure, mortality, and escapement accompanied stock recovery of the estuarine Red Drum population of Texas

AbstractObjectiveWe analyzed a fishery‐independent catch time series in the context of predicted historical age structure of Red Drum Sciaenops ocellatus for the years 1980–2019. This time series roughly coincided with closure of the commercial fishery in Texas (in 1981) and federal waters (in 1987). Changes in size and age were used to estimate changes in mortality and offshore escapement.MethodsOtoliths collected from Red Drum between 1997 and 2015 in Texas were used to create seasonal length‐at‐age growth functions, which were then used to estimate ages (based on total length) of all Red Drum encountered in fishery‐independent gill‐net samples collected by the Texas Parks and Wildlife Department during 1980–2019 (total n = 311,150). Temporal changes in observed body size and overall catch were used to predict annualized changes in mean age, mortality, and offshore escapement of the estuarine population.ResultThe initial 14‐year period (1980–1993) was characterized by rapid increases in mean catch per hour and mean total length (mm) in fishery‐independent samples, followed by relative stability for the remainder of the time series. There was a 55% increase in estimated mean age of Red Drum when comparing 1980 (mean age = 0.84 year) to 2019 (1.30 years). There were also rapid and significant declines in total mortality (Z; estimated via catch curves) and increases in offshore escapement (estimated indirectly from mortality) in the initial recovery period.ConclusionThe current estuarine population of Red Drum in Texas is significantly larger and older than it was at the onset of fishery management measures, and offshore escapement is annually well above the current target level of 30% set by the federal fisheries management plan. These findings suggest that regulations put into effect starting in the 1980s have succeeded in recovering the estuarine Red Drum population in Texas.

Investigating the Stability of the Candi Kelir using DDA

Candi Kelir, which is a candi in Prambanan, is a historical masonry structures threatened by high potency of earthquake in Indonesia. Investigating the stability of Candi Prambanan is essential for determining the capability to withstand earthquake loads. Discontinuous Deformation Analysis (DDA) has been extensively applied in the disciplines of rock mechanics and rock engineering. Two-dimensional DDA is chosen to simulate the behaviour of Candi Kelir towards earthquake load. Geometry of each block of Candi Kelir is obtained by Close Range Photogrammetry (CRP) method. Simulation of Candi Kelir is conducted using the seismic excitation from the destructive 2006 Yogyakarta Earthquake. The result of the simulation shows the capability of DDA to simulate the behaviour of masonry structure which allows fully detachment of the blocks. During the earthquake, most of the top structures are failing, thus DDA can simulate and generate the result. Wider application of DDA into the historical masonry structure will be helpful to prevent more damage due to earthquakes.

Diaspora Modern

Abstract Diaspora is a defining condition of the history of the past century, a prehistory to our disastrous moment in time and also the foundation of our political landscape. Yet it is notably absent in much art-historical discussion of modernism, despite the fact that the experiences of diaspora and migration are often embedded in the lives of modernist artists and other actors; in the formations, networks, and dispersals of modernist institutions and group affiliations; and in the deployment of characteristically modernist artistic strategies (temporal fragmentation, collage, montage, and the readymade) that manifest a dialectical entanglement of self and other. This essay ponders the disconnect between the historical structures of modernism in art and its theorization, and considers the questions: Can diaspora and diasporic thinking help further our understanding of the twentieth century in art? Can it help us in reconsidering modernism from a diasporic perspective today? As prompts for further thought, the text considers four historical episodes in which ideas of diaspora, modernity, and modernism are entwined: W.E.B. Du Bois and the First Universal Races Congress in London 1911; Georg Simmel, Du Bois, and Alain Locke in Berlin and the emergence of a matrix of modern sociological thinking; Mikhail Bakhtin in exile in Kazakhstan and the formation of his dialogical philosophy of language; and Aaron Douglas and Meyer Shapiro at the First American Artists’ Congress in 1936 and in the pages of Art Front.

Lightweight mortars with chalcedonite – Towards functional and durable materials for repair of historical masonry

In the repair of historical masonry and listed buildings, the requirements for compatibility and preservation of the original appearance and cultural and historical value of the rehabilitated structure are often discussed. In particular, technical, technological and material compatibility is often addressed by engineers and conservation professionals and the resulting solution often involves finding a compromise between an ideal, technically functional solution and preserving the historic value of the building for future generations. The material solution of mortars for repair of historical structures is based on the application of a suitable binder and porous filler, which allows achieve their high porosity, water vapor permeability, sufficient strength and durability. Obviously, there is no single ideal material solution for these mortars and it is always necessary to take into account the current state of the reconstructed structure and the composition and properties of the original materials in their design and application. The aim of the research presented here was to design and experimentally assess rendering and plastering mortars based on lime hydrate and natural hydraulic lime partially lightened with chalcedonite as a porous aggregate. The results of the material tests were compared with criteria imposed in WTA recommendation 2-9-03.2020/E. Chalcedonite was used as an alternative filler to silica sand and its application enabled the required values of porosity, compressive strength, water absorption coefficient and water vapor diffusion resistance factor to be achieved. The lightened plasters also showed increased hygroscopicity, low thermal conductivity and increased resistance to salt crystallization. Depending on the binder used and the demanded mechanical strength, the examined mortars thus represent materials applicable in the repair of damp and saline masonry of historical buildings.

Durability of organic blended lime mortar and its shear bond strength in brick masonry

Durability of historical structures is one of the most significant parameters that is appreciable and is of utmost importance. From studies conducted earlier it has been witnessed that the lime mortar used in these structures is embedded with organic additives that has enhanced the different properties of the mortar. Therefore, understanding the behaviour of these additives and their impact on the durability of the mortar is of significance use. To witness the effect of an additives on the mortar, jaggery, egg, and jute are taken as organic additives in the present study. To determine the durability properties of these organic-based lime mortar, acid attack, alkali attack, and wetting and drying tests has been performed. Further, the bond strength of these organic lime mortar in brick masonry has been examined by performing a triplet test. According to the sulphuric acid attack test, the lime mortar with jute as an additive has shown the best results with only a 5% loss in strength which is 23 % in lime mortar without any additive. In the alkali resistance test also, jute has shown exceptional behaviour with a strength loss of 1.5% which is 22% in lime mortar without additive. In the triplet test, the shear bond strength of jaggery-based mortar is 27.77% higher than the mortar without additive, hence showing the best result in the shear bond test. These results can be used in the studies conducted to repair and reconstruction of our heritage structures that need to be revived.

Determination of the seismic performance of a historical masonry structure using the equivalent seismic load method

Mosques and masjids are the most important parts of Islamic culture in terms of their architectural and structural characteristics. These structures also provide an important insight into the construction techniques and historical process of the region in which they were built. Many of these structures are still in use around the world. However, most historical mosques and masjids are vulnerable to earthquakes or are not strong enough. Therefore, it is important to know the risk status of these important structures with respect to earthquake forces and to carry out the necessary strengthening works. In this study, the performance of the historical Ahi Musa Masjid (built in 1185) was investigated using the linear earthquake solution method, which provides a practical approach to determining the earthquake performance of historical structures. Firstly, studies were carried out to determine the geometric and material properties of the historical Masjid. A finite element model of the historical Masjid was then constructed and linear performance analyses were performed under vertical loads and equivalent earthquake loads. As a result of the analyses, the displacement ratios, compressive and shear stresses of the historical Masjid were obtained and evaluated according to the collapse prevention performance level for the earthquake level DD-3, which is one of the performance levels recommended for historical structures of local importance in the Guidelines for the Management of Earthquake Risks for Historical Structures. The aforementioned stress and drift ratio values remained below the reference values. In conclusion, the Masjid will safely withstand the potential effects of an earthquake.

City and Brain Analogy: a Sample for Conservative Versus Adaptive Phenotypical Vision of a Genotypical Heritage

Historical urban settlements and traditional structures are significant indicators and meaningful documents of past ways of life. From a contextual perspective, the preservation of these values and the revitalization of architectural heritage are like sustaining through the conservation of the integrated and continuous culture tied to the past just like a human brain does. The present study encompasses all dimensions of a strategic model to conservation versus adaptation developed for one of the historical building types (Vienna Gasometers), which holds substantial historical values. It involves addressing functions, spatial organization, the manner of interaction with historical building remnants, old-new compatibility, form, structure, and material usage, as well as conducting architectural evaluations. In this study, first; following the architectural assessment of each monumental structure, their spatial, formal, functional, and structural relationships with each other are examined to grow these essences and values for a new vision of the city. Second, the advantages and disadvantages of the conservation approach are critiqued in comparison to adaptive renovation of the city heritages. As an illustrative example, the Simmering region and Gasometer structures located in the outer parts of Austria which is historically the most iconic heritage have been chosen. The preservation of the physical characteristics of Gasometer monumental structures while renovation of the functions of the space within this framework reflect not only Europe's industrial, historical, and social evolution but also hold significance in terms of safeguarding socio-economic and cultural values. Furthermore, they contribute to shaping contemporary notions of conservation while adapting them to the vision of the new era.

Racism against racialized migrants in healthcare in Europe: a scoping review

BackgroundRacism is frequently mentioned as a social determinant of migrants’ health and a barrier to health services. However, in the European context, racism and its impact on racialized migrants’ access to healthcare is remarkably under-researched. This scoping review makes a first step toward filling this void by mapping the existing literature on racial and ethnic discrimination against racialized migrants in healthcare in Europe, identifying evidence gaps, and offering recommendations for future research on this topic.MethodsFollowing PRISMA guidelines, four databases were searched for empirical studies published in English between 1992 and 2022. Studies were included if they report findings on manifestations, experiences and/or impacts of racial or ethnic discrimination against racialized migrants in a healthcare setting in a European country. They were summarized by study characteristics (geographical scope, study design, research question and measures) and research findings were synthesized.ResultsOut of 2365 initial hits, 1724 records were included in the title/abstract-screening, 87 records in the full text-screening, and 38 records in the data extraction. For many country and healthcare contexts, evidence on racism in healthcare is lacking. Most studies apply an explorative qualitative research design; comparability and generalizability of research results are low. Our analysis furthermore shows a near-exclusive research focus on racism on the interpersonal level as compared to institutional and structural levels. Our synthesis of study results identifies three interrelated ways in which racism manifests in and impacts migrants’ healthcare: 1) general anti-migration bias, 2) health- and healthcare-related prejudice, and 3) differential medical treatment.ConclusionsOur review underscores how racism reinforces inequities in healthcare access and quality for racialized migrants. It also highlights the need for more research on racism in Europe across a greater scope of country contexts, healthcare settings and migrant/racialized categories in order to understand specific forms of racism and capture race as a context-contingent social construct. It is critical that future research includes the consideration of individual-level racism as embedded in racism on institutional and structural levels. Methods and insights from other disciplines may help to critically examine concepts in light of underlying historical, sociopolitical and socioeconomic processes and structures, and to improve methods for researching racialization and racism in healthcare.

Comparing the impact of live-tree versus historic-timber data on palaeoenvironmental inferences in tree-ring science, eastern North America

Dendroarchaeological data from historic structures and artefacts have the potential to extend tree-ring chronologies spatially and temporally, especially where old-growth forests have been extensively modified or harvested. While these data may contribute to an improved understanding of past climate and ecology, critical differences in the properties of live-tree and historic-timber data might affect results and interpretations of large-scale studies, such as those relying on large datasets from public databases like the International Tree-Ring Data Bank (ITRDB). The objective of this work was to compare summary measures of live-tree versus historic-timber datasets likely to affect outcomes and inferences of typical paleoenvironmental applications. We used 99 live-tree (LT) and 41 historic-timber (HT) datasets collected in the Appalachian region of the eastern United States and compared common analytical measures for understanding past climate and ecology, including temporal coverage, species composition, recruitment patterns, segment length, series coherence/mean interseries correlation (as Rbar), expressed population signal (EPS), subsample signal strength (SSS) and response to drought and extreme climate events. We found that tree-ring data from historic timbers record some ecological events similarly to live trees and are sensitive to some climate conditions, with important caveats related to the influence of site and tree selection on analytical measures. In some cases, these caveats can be overcome through improved collection of metadata and additional analyses. In all cases, potential differences in LT and HT data should be considered by those who perform large-scale analyses using public tree ring databases, especially as more scientists contribute historic-timber datasets.

Deep Learning for the Segmentation of Large-Scale Surveys of Historic Masonry: A New Tool for Building Archaeology Applied at the Basilica of St Anthony in Padua

ABSTRACT In the last decade, the documentation of historical buildings has made tremendous progress in generalising the use of high-precision laser scanning and drone photogrammetry. Yet the potential of digital surveying is not fully exploited due to difficulties in manually analysing large amounts of collected data. Machine learning offers immense potential as a game-changer in building archaeology, especially for the documentation of structures composed of millions of units. This paper presents the first segmentation of large-scale surveys of historic masonry using machine learning, using the thirteenth-century Basilica of St Anthony (Padua, Italy) as a case study. Based on a drone survey of the north façade of the building (110 × 70 m), a state-of-the-art non-learning segmentation approach is described and its limitations for historical structures are illustrated. Then, a new workflow based on convolutional neural networks (CNN) is presented. The result is a precise mapping of about 300,000 individual bricks showing a large variety of formats and bonds. The automatic surveys are analysed using visual programming language (VPL), enabling a rapid and feature-based identification of building phases and repair interventions. The outcome demonstrates the validity of machine learning for the analysis of historical structures and its potential in the field of heritage.

Deputy heads—leadership and power in change?

ABSTRACT Much current research emphasizes the importance of leadership as an interactive activity in leading school change and improvement. In the Norwegian context, there is growing interest in redesigning the historical hierarchical leadership structure, with a single school leader at the top to a more distributed leadership model that includes several middle leader levels, including deputy heads. While research has been conducted on middle leaders and distributed leadership as an interactive activity, few empirical studies to date have investigated how changing leadership structures affect the relation between leadership and power and how this situation can influence deputy heads’ room for maneuvering. In this article we use data from a Norwegian case to investigate deputy heads’ increased responsibility toward leading school change and improvement and how these changes influence questions of power. The analysis indicates that different forms of power influence deputy heads’ room for maneuvering.

Challenges in Characterization and Development of Suitable Historic Repair Mortars

The importance of compatible restoration of historic masonries cannot be overemphasized, as it helps maintain the historic structures for sustainable development, economic growth, and the representation of a country's history. This paper acknowledges the existence of extensive research work on historic mortar characterization, the proposition of restoration materials, and the awareness raised about the use of incompatible restoration materials. However, the concept of historic mortar characterization still faces some challenges in methodology, material sampling, and mortar decay that need to be confronted. The problem extends further to designing and producing compatible restoration mortars for historical monuments. The work has not been extended to evaluate the compatibility and durability of the designed mortars. This creates uncertainty about the effectiveness of such proposed solutions. These could be overcome by analyzing the physical, chemical, mineralogical, and mechanical properties of the original representative mortar samples collected from historic structures and the proposed repair mortars before executing repairs. It is believed that investigations into the mix designs help achieve successful restoration work. This review presents the recent advances in historic mortar characterization and is intended to be a useful tool for historic restoration teams when tackling conservation activities on historic masonries.