DISPLACEMENT-BASED SEISMIC ASSESSMENT OF REINFORCED CONCRETE BUILDINGS

Abstract

Seismic assessment of existing reinforced concrete frame and shear wall buildings is discussed. Building on an earlier preliminary assessment procedure incorporating aspects of capacity design into a systems approach for assessment, suggestions are made towards a displacement-based, rather than forced-based, approach to determining available seismic capacity. Based on results from recent experimental programs, procedures are proposed for assessing member strength including column and beam-column joint shear-strength, that result in less conservative estimates of performance than would result from application of existing code rules.     

Discrete Element Modeling of Groin Vault Displacement Capacity

Displacements experienced by many historic masonry structures concentrate at masonry joints and can be large before collapse is a concern, making modeling of stability using discrete element modeling (DEM) particularly suitable. In this study, masonry groin vault and arch models with several geometries were subjected to horizontal and vertical support displacements using DEM. Support movements were applied in a quasi-static manner to simulate the support settlement process. Displacements at collapse and at the point when the first block fell from the vault were recorded. Block separation and mechanisms were also noted during the simulations. A two-dimensional (2D) analytical model using thrust line analysis was developed to help evaluate the DEM results. In general, the displacements at first block fall were relatively large but significantly less than those at collapse. The groin vaults and arches exhibited significantly higher capacity to sustain vertical support displacement compared to horizontal displacements. For many geometries, the DEM collapse displacements of the groin vaults compared reasonably well to similar arches, indicating that the displacement capacity of groin vaults can be reasonably estimated using 2D simplifications. However, for certain geometries, three-dimensional effects were found to significantly affect displacement capacity.     

Ambivalent greenings,collateral conservation: Negotiating ecology in a United Nations buffer zone

This article focuses on the politics of environmental conservation in the UN Buffer Zone (BZ) that divides the island of Cyprus. On the one hand, it underscores the unintended conservation benefits which resulted after the violent depopulation of the BZ. On the other hand, it shows how the protracted conflict and its transformation into a post-violent one, has ‘softened up’ the BZ, and gave rise to new demands for human access and land development. The BZ as a spatial legacy of the Cyprus conflict thus illustrates the paradoxes of conservation practices in unintended ecological zones, which we term collateral conservation. It also underscores the modi vivendi negotiated among a broadened range of actors in pursuit of rival anthropocentric or ecological goals.     

The Purposes of Land Settlement in the Anglo-Egyptian Sudan, 1898–1914: Drawing Paths through the Weeds

This article examines the programme of land surveying and registration that was undertaken by the British-led administration of the Anglo-Egyptian Sudan in the period 1898–1914. The Legal Secretary, Edgar Bonham Carter, stated that programme was the most important project of his division in this period. Scholars have shown that the programme, known as land ‘settlement’, was used to build alliances with elites and to clarify title for European investors in the new irrigation scheme at Gezira. This article argues that, as such, the ambitions of land settlement were relatively limited. In many other colonies, and in Britain itself, politicians and administrators across the political spectrum saw the reform of private property in land as the key for addressing structural problems in agricultural labour. One might have thought that, the Sudan, land settlement might have provided a means of addressing the dependence on slave labour in agriculture. The article demonstrates that, except for a small number of administrators (including Bonham Carter), this was not the case. The general indifference to slavery itself carried through to an indifference to the transformative potential of land law. The article examines the proposals of this minority of administrators, and contrasts their views with the majority’s focus on land settlement as demonstration and opportunity to enhance state power.     

‘It’s the best place on Earth’: Newfoundland women’s outmigration,diaspora and the myth of return*

This article explores Newfoundland women’s experiences of outmigration as a gendered process of displacement. Experiences of displacement can provide significant insight into Newfoundland and Labrador’s fractured political relationship with the nation of Canada. This article argues that Newfoundland outmigration must be viewed through the lenses of diaspora and intersectionality, as nationalist sentiment and the province’s peripheral place within Canada affect women’s experiences of outmigration. Tensions shaped by gender, ethnicity and socio-economic status affect their ability to integrate into Canadian society and influence their decisions about returning home.     

Infrastructural Activism: Google Bus Blockades,Affective Politics,and Environmental Gentrification in San Francisco

Between 2013 and 2018, the San Francisco Bay Area saw the rise of “Google bus blockades”—a form of protest against gentrification, growing inequality and a housing crisis linked to the economic impacts of the technology sector on the region. Based on two years of ethnographic fieldwork with housing activists in the San Francisco Bay Area, this article argues that the disruptive tactic of “the Google Bus blockade” can be understood as a form of infrastructural activism—a flexible political form that uses the interruption of infrastructure for political ends. The blockades politicised the “Google buses” and transformed them into symbols of gentrification and sites of resistance. Protestors constructed a political analysis that drew connections between struggles for housing, racial and environmental justice and brought together material, affective and political critiques of infrastructure.     

论日语请求行为得体性的实现

请求行为普遍而且敏感,它是人类交际中不可避免的社会活动。得体性作为请求行为所必须遵循的礼貌原则,既牵涉到语言自身,又牵涉到许多诸如风俗习惯、价值观念、社会地位、人际关系、环境、地点、时间等社会文化因素。本文通过分析中国学生运用日语表达“请求”这一言语行为时出现的语用失误,探讨中日两种文化在语言语用和社交语用方面存在的差异,旨在找出隐伏在这些失误背后的、易引起误会和冲突的文化因素,并在此基础上,提出对策,以帮助日语学习者自觉改变和调整固有的框框,提高语用能力。     

Adult Male Mortality in India

This paper presents levels and trends of adult male mortality in India and its major states during the post-independence period applying the widowhood method on census data. It also estimates adult male mortality for all the districts from major states of India. We adjusted widowhood estimates for possible bias due to remarriages and examined the sensitivity of adjusted estimates to different scenarios of remarriage rates. Comparison of widowhood estimates with direct estimates from official sources supports the credibility of widowhood estimates. Information obtained from widows aged 40–44 and 45–49 provided the most convincing patterns of adult mortality. Trends in adult mortality suggest that maximum gain in ₄₅q₁₅ for India and its states occurred during 1949–1960. Adult male mortality varied substantially across the states of India. Although adult life expectancy has been rising in India, the rate of mortality reduction has been decreasing over the last few decades.     

From Crime to Coercion: Policing Dissent in Abeokuta,Nigeria, 1900–1940

Indirect rule figured prominently in Nigeria’s colonial administration, but historians understand more about the abstract tenets of this administrative strategy than they do about its everyday implementation. This article investigates the early history of the Native Authority Police Force in the town of Abeokuta in order to trace a larger move towards coercive forms of administration in the early twentieth century. In this period the police in Abeokuta developed from a primarily civil force tasked with managing crime in the rapidly growing town, into a political implement of the colonial government. It became critical in preserving the authority of both the local traditional ruler and the colonial administration behind him. In Abeokuta, this transition was largely precipitated by the 1918 Adubi War and the period of increased surveillance that followed it. This created new responsibilities and powers for the police, expanding their role in Abeokuta’s administration and raising their stock in the colonial administrative hierarchy.     

New‐Build Gentrification and the Everyday Displacement of Polish Immigrant Tenants in Greenpoint,Brooklyn

In response to research that has downplayed or denied the reality of gentrification‐induced displacement, critical urban geographers have called for rethinking the concept of displacement. This article takes up that call by examining the impact of new‐build gentrification on the everyday place‐making abilities of Polish immigrant tenants in Greenpoint, Brooklyn. Based on nearly four years of work as a tenant organizer, this article looks at the forms of “everyday displacement”—the ongoing loss of the agency, freedom, and security to “make place”—experienced by immigrant tenants who struggle to remain in the neighborhood. Drawing upon Lefebvre's spatial triad and Blomley's work on the social relations of property, this article argues that everyday displacement is experienced through the production of new spaces of prohibition, appropriation, and insecurity that constitute a form of neighborhood erasure.