Seismic Evaluation of Tall Buildings Using a Simplified but Accurate Analysis Procedure

A simplified analysis procedure for evaluating the nonlinear seismic responses of tall reinforced concrete (RC) buildings is examined in this study. It is called the Uncoupled Modal Response History Analysis (UMRHA) procedure. It can be viewed as an extended version of the classical modal analysis procedure, where the nonlinear response of each vibration mode is first computed, and they are later on combined into the total response of the structure. The procedure requires the knowledge of the modal hysteretic behavior, which can be obtained from a cyclic modal pushover analysis. The responses of four tall buildings in Bangkok to distant large earthquakes are computed by this procedure and compared with those obtained from the Nonlinear Response History Analysis (NLRHA) procedure. These four buildings have different heights—varying from 20 to 44 stories, different configurations of floor plan, and different arrangement of RC walls. The comparison shows that the UMRHA procedure is able to accurately compute the story shears and story overturning moments, floor accelerations, and inter-story drifts of all these tall buildings. The required computational effort is also extremely low compared to that of the NLRHA procedure. Moreover, since the UMRHA procedure computes the response of each individual vibration mode, it provides more understanding and insight into the complex nonlinear seismic responses of these tall buildings.     

A High-Performance Quadrilateral Flat Shell Element for Seismic Collapse Simulation of Tall Buildings and Its Implementation in OpenSees

Shear walls are important lateral force-resistant components of tall buildings. Hence, a reliable numerical model that can accurately represent the mechanical characteristics and large deformations of shear walls is critical for realistic collapse simulation of tall buildings. Based on the theory of generalized conforming element, a high-performance quadrilateral flat shell element, NLDKGQ, accounting for the large deformation using the updated Lagrangian formulation, is proposed herein and implemented in OpenSees. The reliability of NLDKGQ is validated using classical benchmark problems and reinforced concrete specimens. In addition, its capability in simulating the collapse of a tall building is also demonstrated.     

Modeling and deterioration mapping of façades in historical urban context by close-range ultra-lightweight UAVs photogrammetry

Deterioration mapping of façades may be a challenging task in historical urban contexts, often characterized by narrow streets and tall buildings. In these situations, the application of Terrestrial Laser Scanning or Terrestrial Photogrammetry does not provide satisfactory results. Furthermore, the use of Unmanned Aerial Vehicles, the so-called “drones”, is generally forbidden in crowded places for safety reasons unless they are lighter than a weight imposed by the regulations in force in each country. This article presents the application of a very small and ultra-lightweight drone (less than 300 g) equipped with a low-cost camera, particularly suitable for operating in very narrow spaces. A close range photogrammetric survey performed to analyze a huge historical building façade in Bologna (Italy) pointed out a good accuracy level, confirmed by the validation of the results carried out by a 3D laser scanner survey. Moreover, a map of the degradation has been realized to support further restoration analysis, demonstrating that this low-cost, fast, and easy-to-use survey technique can be applied to other similar urban contexts at the same time.     

The spatial dimension of agency: the everyday urban practices of Filipina domestic workers in Amman,Jordan

This article examines the strategies that Filipina migrant domestic workers in Jordan have developed to create new opportunities within the restrictive Kafala migration system. Based on short-term live-in contracts, the Kafala system tends to confine migrant women to employers’ homes, thus restricting their access to urban amenities and limiting their interactions with co-ethnics. However, Filipina migrant domestic workers transform temporary migration into a longer-term experience by increasing their knowledge of the city and going from live-in workers to live-out or freelance workers. This article contributes to understandings of migrant women’s agency by considering the spatial construction of agency in urban spaces. I argue that space and agency are entwined. In order to highlight the spatial dimension of agency, I use the concept of ‘regime of visibility’ to show how migrant women make their agency visible to others by accessing public spaces. Connecting agency with regimes of visibility allows me to question the place and role of migrant women in urban public spaces. Especially, I analyze that tensions in public spaces are not merely a reaction to the presence of women, but are also intended to prevent the visibility of individual agency.     

Public religion and urban space in Europe

Conflicts related to demographic and cultural change in Europe regularly find their expression in struggles over the presence and visibility of religious buildings and groups. As this editorial argues, these conflicts can best be understood from a postsecular perspective that takes into account overlapping and diverging histories of state-formation and secularization. The papers collected for this special issue on public religion and urban space demonstrate that many of the difficulties that European societies face in accommodating religious diversity stem from historically formed relationships between national political identities and religious identities. In many European cases, secularization did not entail a fundamental separation between religion and politics but the formal establishment of one single national church or two competing ones, but territorially based national churches. One of the consequences of these types of establishments is that certain religious traditions are generally described and experienced as fitting with the nation and others are not. The contributors to this special issue show in detail that the struggles of contemporary religious movements in Europe to become present in the public domain are related to commonly accepted understandings of where and how religion should manifest itself in the urban environment, based on the public life of religious traditions that are considered part of the nation.     

Informal housing,spatial structure,and city compactness

This paper develops a monocentric city model with a formal and an informal sector in the housing industry. While formal developers build houses renting land from landowners, informal developers use land for free. However, informal developers must incur defensive expenditures to avoid government intervention. In equilibrium, at any distance of the central business district (CBD), informal developers use land until the value of the marginal productivity of land equals the defensive expenditures per unit of land. The model shows the land allocated to produce short informal (tall formal) buildings increases (decreases) with distance to the CBD. Thus, the model introduces a new source of spatial variation of building height. The model also shows that a higher level of informal housing increases the spatial size of a city and reduces the height of its buildings.     

A New Proposed Passive Mega-Sub Controlled Structure and Response Control

It is still a serious challenge for structural engineers to effectively reduce the seismic responses of tall and super tall buildings to further improve these structural safeties. In order to solve this problem, in this article a new kind of structural configuration, named passive mega-sub controlled structure (PMSCS), is presented, which is constructed by applying the structural control principle into structural configuration itself, to form a new structure with obvious response self-control ability, instead of employing the conventional method. In the analysis of PMSCS the equations of motion of the seismically excited system are developed, based on a realistic analytical model of the complete mega-structural system. Expressions of the displacement and acceleration response of the structure, resulting from simulated earthquake ground motions represented by stationary and nonstationary random processes, are derived. These responses are then determined for both the PMSCS and its conventional mega-sub structure (MSS) counterpart, whose configuration was modeled after the traditional mega-frame that was used in the construction of the Tokyo City Hall. A parametric study of the structural characteristics that influence the response control effectiveness of the PMSCS is presented and discussed. The region over which these structural characteristics yield the optimum seismic response control of the PMSCS is identified and serves as a very useful design tool for practitioners. The study illustrates that the proposed PMSCS offers an effective means of controlling the seismic displacement and acceleration response of tall/super-tall mega-systems. It also overcomes shortcomings exhibited in earlier proposed mega-sub controlled structural configurations.     

The Influence of Building Attributes on Residents' ‘Images of the Past’ in the Architecture of Salt City,Jordan

This paper presents an empirical study conducted in a small traditional city, Salt, Jordan. An investigation was made to examine residents' ‘images of the past’. The objective was to identify building attributes that influence these residents' images. A survey research design using multiple sorting tasks with open‐ended questions was used to identify these building attributes. The images were elicited through the observation of coloured photographs of a sample of older buildings in the city centre. Images of the past were examined within three content areas: knowledge of the past; date of construction; and character of the past of Salt City. The building attributes investigated were: contour, size, shape, surface quality, signage, visibility, use, and significance. The results of the study suggest that older buildings in the centre of the city evoked similar images of the past focused on public or social buildings along with residential settlement building. Attributes relating to images of the past were original use, date of construction, historic signage, and historic integrity. This study presents an approach for operationalising an image of the past.     

Snow Fences: Then and Now

Snow fences are an increasingly widespread cultural feature in the great east-west “snow belt” of the northern hemisphere. They are there not only to protect railroads, highways and buildings from the hazards of blowing snow, but also whole towns subject to the ravages of avalanches. Although their origin is unknown, their construction and use have been advanced and improved greatly by many experimenters of more than a dozen nationalities since the middle of the 19th century.

A modern example of snow fence use is analyzed for a locally named section of Interstate 80 between Laramie and Rawlins in southern Wyoming known as the “Sno Chi Minh Trail.” Here big systems of mostly 12 feet high snow fences line more than half of the western side of the highway for 50 miles. They have reduced accidents and plowing costs by significantly improving visibility in “ground blizzards” of fast-blowing snow.     

Re-using ‘uncomfortable heritage’: the case of the 1933 building,Shanghai

This paper opens up a discussion over the processes of forgetting and remembering that occur in the adaptive reuse of quite commonplace buildings that, nevertheless, have been classified as ‘heritage’. For most buildings survival depends upon finding a new economic use once original use has ceased. At this point decisions are also made about what stories are carried forward from the building’s past. The principal case study discussed in this paper is the former Shanghai Municipal Abattoir, a modernist concrete sculpture now branded 1933 Shanghai. The paper delineates how a process of ‘strategic forgetting and selective remembrance’ has been undertaken, negotiating the bloody nature of the building’s past, in its reuse as an upscale commercial venue. Reuse is further considered within the wider frames of a 1920–1930s Shanghai urban branding ‘imaginary’ and as a ‘building of control and reform’ – a category of buildings developed from the eighteenth-century European Enlightenment-thinking. In reflecting upon this negotiation in the heritage making process with potentially difficult past events, we propose the category of ‘uncomfortable heritage’, as part of a wider spectrum of ‘dark heritage’, and conclude with a final reflection upon 1933 Shanghai as a heterotopic space.     

Metal Ties in Genoa,Italy: Manufacture,Trade, and Use from the 15th to the 18th Century

The article deals with the use of metal ties in an ancient and stratified urban context, the city of Genoa, starting from the notarial documents preserved in its State Archives. The work has different objectives: to show the results that can be obtained, on an urban scale, thanks to a research path that compares indirect sources of different types with the observation of historical buildings; to highlight the “weight” and the role that the ties, often hidden, had in buildings, and not only the monumental ones; to increase knowledge of the production process of this constructive element. The wide and diversified use of metal ties found in Genoa seems to proceed in parallel, in the 15th century, with the development of a flourishing productive and mercantile business based on the commercial monopoly of the hematite of the island of Elba by the city oligarchy and, between the 16th and 17th centuries, with the huge investments in the construction sector highlighted by the abundant documentary sources.     

In the Palace of the Fallen king: The Royal Residential Complex at Aguateca,Guatemala

Abstract

The Aguateca Archaeological Project extensively excavated two structures (M7-22 andM7-32) in the Palace Group of the Late Classic Maya (A.C. 600–830) center of Aguateca, Guatemala. Multiple lines of evidence, including site layout, architectural features, soil chemistry, objects stored in a sealed room, and abandonment processes, suggest that these were the buildings where the ruler and his family lived and worked. The use of space in these structures shows some similarities to those of the rapidly abandoned elite residences at Aguateca and of palace-type buildings at other Maya centers. The occupants of this royal complex retained a certain level of visibility, indicating the importance of the ruler’s body as the focus of theatrical display. After the royal family evacuated the center, an invading enemy ritually destroyed these buildings, attesting the symbolic importance of the royal residences. The center was almost completely abandoned after this incursion.     

Integrating Archaeological Heritage into Towns and Settlements

ABSTRACT

This article explores factors concerning the urban integration of archaeological heritage in towns and settlements. Archaeological heritage refers to visible, immovable archaeological remains (such as the remains of buildings or structures), sites, and areas (larger complexes). As part of the multidisciplinary process of archaeological heritage management, based on understanding the significance of a site and the goal of enhancing and preserving archaeological heritage in situ, urban integration and its determining factors have not been the subject of systematic research. The present study is derived from the application of deductive research based on theoretical assumptions validated by a qualitative survey. Research has identified 17 factors as the basis for the urban integration of archaeological heritage in towns and settlements. These factors represent a theoretical and practical contribution not only to urban planning but also to archaeological heritage management.     

International regulation of historic buildings and nationalism: the role of UNESCO

This article focuses on the (ambiguous) relationships between nationalism and international regulation of historic buildings, namely, the activity of UNESCO in this field. It studies two different forms of UNESCO intervention: the creation of a list of world heritage sites of outstanding universal value, which includes several historic cities and buildings; and UNESCO Recommendations aimed at protecting historic urban landscape. The article shows that UNESCO seems to favour both political and cultural forms of nationalism and can significantly affect the nationalistic use of historic buildings and, more broadly, affect on the very idea of Nation and nationalism.     

Factors Affecting Late Twentieth Century Land Use Patterns in Kamakura City,Japan

Land use patterns can be viewed as a reflection of various factors including zoning regulations and environmental and social influences. To understand the effects of these factors, late twentieth century land use data for Kamakura City, Japan were analysed in relation to zoning regulations and geomorphological influences using geographic information systems techniques. Kamakura is a typical example of an Asian historic city experiencing the pressures of recent urbanisation. Statistical analyses, including principal component analysis, were employed to identify factors affecting changes in major land use patterns over time and space. The rapid increase in population and government regulation in the 1970s led to the construction of low-rise buildings in piedmont areas. However, topography and conservation activities limited construction to areas with slope angles below about 10°. In the late 1980s and early 1990s, the area of vacant land on the urban lowlands increased due to the large increases in land value during the Japanese Bubble Economy phase. Land use intensified in most urban areas, although hilly areas were still characterised by low-rise buildings. Although urban sprawl has occurred in many cities in Asia, this has been limited in Kamakura because of strong land use regulation and conservation activities. However, the city has experienced high-rise development in its urban lowlands.     

Waste and its masquerades: On the production of urban natures in Kochi,India

Waste management has been a focal point in ethnographic research, yet its aesthetic and ideological facets in shaping ‘urban nature’ have been largely overlooked. The article delves into a comparative study of two parks in Kochi, a South Indian city, examining the intersection of environmental aesthetics, infrastructural visibility, and the conceptualization of urban nature. Through this juxtaposition, the study elucidates how divergent waste management strategies reflect broader ideologies concerning urban environments and their role in urban development initiatives. The article posits that waste and its management are not peripheral elements in the urban experience of nature; rather, they are integral components that shape it.     

Imaging the materiality of a diaspora: Recording the biographies of Greek Orthodox church buildings in London

The materiality of world diasporas – in every form, from landmark features to everyday objects – is a relatively modern approach towards studying the diasporas' relationship with both homeland and hostland. Photo narratives and various modes of imaging can be employed to better record, assess and disseminate the narratives of diasporic lifeways in terms of their material culture. This article examines how Greek Orthodox communities have altered Western denomination church buildings in London to serve their spiritual and community needs. The new, amalgamated characteristics are described, while the debate around the role these religious communities should play in the hostland is also discussed.     

Seismic Vulnerability of Historical Masonry Aggregate Buildings in Oriental Sicily

ABSTRACT

The seismic vulnerability assessment of historical UnReinforced Masonry (URM) buildings is a very complex task since it is strongly related to a great variety both of geometrical layouts and of masonry mechanical characteristics. In this article, some results of a Catania University research project, denomined “FIR 2014”, focused on the seismic vulnerability estimation of historical buildings, built in Catania after the 1963 earthquake, are presented. First, a detailed typological analysis of the considered urban fabric, characterized by typical residential masonry buildings, has been performed. Such analysis allowed recognizing an elementary structural modulus, which has been studied according to different geometrical layouts representative of isolated or aggregate buildings. The results of nonlinear static analyses, performed by applying an innovative macro-element approach, allowed for the assessment the seismic vulnerability of typical URM buildings coherently to the Italian seismic code. The adopted macro-element strategy for the seismic assessment of aggregate masonry buildings, although related to a specific historical center, may be applied to similar urban fabrics and can also be used for the calibration and validation of fast seismic assessment strategies, particularly useful for the evaluation of the seismic risk at urban scale.     

城市犯罪中的非公共空间盲区及其综合治理

城市犯罪中的空间盲区是形成犯罪载体的重要因素。本文在阐明城市犯罪空间盲区的产生机制及其综合治理的任务的基础上,重点分析了非公共空间盲区的防控脆弱性及其外在、内在的防控盲点,提出了治理此类盲区的工作思路,讨论了治理非公共空间盲区的外部环境和内部环境以及提高非公共空间警戒能力的工作途径。成功的综合治理可以对有效地预防犯罪、中止犯罪、制伏罪犯、消减犯罪危害性等起到积极作用,可以为城市犯罪的空间防控作出积极贡献。