Seismic Overstrength of Shear Walls in Parking Structures with Flexible Diaphragms

The objective in current design practice for parking structures is that energy is dissipated through the formation of plastic hinges at the base of shear walls while floor diaphragms remain elastic and are vertically supported by a combination of shear walls and gravity resisting columns. Unfortunately, this objective is not always achieved due to inaccuracies in current methods for calculating demands on shear walls and in calculating the capacity of shear walls (IBC 2003 International Building Code. International Conference of Building Officials. Whittier, CA.  [Google Scholar], ACI code). When demands are overestimated and capacity underestimated, then diaphragm can fail prior to flexural yield of shear walls as was observed in several parking structures in the 1994 Northridge earthquake.

Eigenvalue and inelastic dynamic response analyses were performed in order to investigate the effects of diaphragm flexibility on wall responses and of wall overstrength on diaphragm responses. The elongated periods of parking structures due to diaphragm flexibility were found to significantly decrease seismic force demand on shear walls relative to what is calculated using codes of practice in which diaphragms are assumed to be rigid. This leads to the over design of shear walls, which further compounds the problem by preventing the flexural yielding of these walls and thereby driving inelastic response to diaphragms. Various degrees of diaphragm flexibility, shear wall layout, seismic zone, and the number of stories were considered in these analyses.

Inelastic static pushover analyses were preformed to investigate the design and capacity evaluation of shear walls. The results illustrate that the shear capacity of walls may be close to twice that calculated by codes of practice. The largest overstrengths were observed in shear walls with low height-to-length ratios in which a significant portion of the lateral load was taken by direct strut action to the foundation and without placing demands on the longitudinal tension reinforcement in the shear walls. The article concludes that methods in codes of practice for calculating shear wall demands and capacities need to be improved if good seismic performance of parking structures is to be achieved.     

Settler colonialism and cultural policy: the colonial foundations and refoundations of Canadian cultural policy

This article aims to reintegrate the colonial history of Canada as part of the grids of analysis for understanding the evolution of its Federal cultural policy. Building on the notion of settler colonialism and its implication for Indigenous population (For the purposes of this paper, the term ‘Indigenous’ is used in place of, perhaps, more popular or familiar terms – such as ‘Aboriginal’ or ‘Native’ – in order to remain consistent with current Indigenous politics. In particular, some Indigenous scholars are reluctant to accept the label Aboriginal because they feel it is consistent with the colonial order imposed by the Canadian government [Alfred and Corntassel 2005, p. 599]). The term Indigenous also alludes to a global political awareness and to forms of alterity between different populations from North America, South America, Asia, and the Pacific. in Canada, this paper documents different transformations in cultural policy and illustrates some of its paradoxes and challenges. Building on principles developed by Indigenous scholars, this article highlights some of the components for decolonizing cultural policy in Canada. It is argued that a post-colonial cultural policy must build on the grounds of ethics (and ethos).     

FRAGILITY ASSESSMENT OF SLAB-COLUMN CONNECTIONS IN EXISTING NON-DUCTILE REINFORCED CONCRETE BUILDINGS

Fragility functions that estimate the probability of exceeding different levels of damage in slab-column connections of existing non-ductile reinforced concrete buildings subjected to earthquakes are presented. The proposed fragility functions are based on experimental data from 16 investigations conducted in the last 36 years that include a total of 82 specimens. Fragility functions corresponding to four damage states are presented as functions of the level of peak interstory drift imposed on the connection. For damage states involving punching shear failure and loss of vertical carrying capacity, the fragility functions are also a function of the vertical shear in the connection produced by gravity loads normalised by the nominal vertical shear strength in the absence of unbalanced moments. Two sources of uncertainty in the estimation of damage as a function of lateral deformation are studied and discussed. The first is the specimen-to-specimen variability of the drifts associated with a damage state, and the second the epistemic uncertainty arising from using small samples of experimental data and from interpreting the experimental results. For a given peak interstorey drift ratio, the proposed fragility curves permit the estimation of the probability of experiencing different levels of damage in slab-column connections.     

The Indigenous Franchise and Assimilation

This article explores the connections between Indigenous enfranchisement and assimilation in Australia. Focusing on testimony given by Indigenous people to the 1961 Select Committee on Voting Rights for Aborigines, and assessing the political and discursive overlaps between enfranchisement and assimilation at this time, the article argues that enfranchisement could both demand and produce forms of social and cultural change that involved Indigenous people becoming more like settler Australians. Indigenous witnesses recognised and often welcomed the acculturation presaged by enfranchisement. But this embrace was not unanimous or unqualified, especially in evidence given by and on behalf of Indigenous people whose lives were partly or wholly beyond the reach of settler institutions.     

Seismic Performance Assessment of Steel Frames with Shape Memory Alloy Connections,Part II – Probabilistic Seismic Demand Assessment

This article is the second of two companion articles that evaluate the seismic performance of steel moment-resisting frames with innovative beam-to-column connections that incorporate shape memory alloy (SMA) elements to enhance the energy dissipation characteristics of such frames. Building upon the finite element models of the three- and nine-story frames that were developed in the first article, the seismic demands on partially restrained frames with and without SMA elements are evaluated within a probabilistic framework. The results of this evaluation, expressed in the form of demand hazard curves, depict the effectiveness of the SMA connections in enhancing building performance over a range of demand levels. Martensitic SMA connections are most effective in controlling deformation demands on the frame from high levels of seismic intensity. In contrast, the recentering capability of superelastic SMA connections make them most suitable for reducing residual deformations in the structure, a reduction that is achieved at the expense of increased deformation demands during strong excitation. However, neither connection is uniformly beneficial at all hazard levels, suggesting that SMA systems must be tailored to the specific performance objectives for the building structural system.     

'A field for private members': The Wolfenden committee and Scottish homosexual law reform, 1950-67

The proceedings and report of the Wolfenden Committee on Prostitution and Homosexual Offences (1954-7) figure prominently in the historiography of homosexuality in later twentieth-century Britain. However, in the main, research has centred on the social politics of the Committee and its implications for sexual law reform in England, and there is a notable lack of regional studies. Using a range of government archives, this article focuses on the written and oral evidence of Scottish witnesses to the Committee. It documents the pre-existing legal and medical provisions for the treatment of 'homosexual offences' in Scotland, and surveys the Scottish evidence for and against the decriminalization of homosexual practices. Thereafter, it examines the views of the Scottish members of the Committee in the context of the Wolfenden Report. The article then surveys the wide-ranging opposition to homosexual law reform within Scotland in the period 1957-67, culminating in its exclusion from the 1967 Sexual Offences Act. Finally, it evaluates the implications of the Scottish experience and concludes that, in some important respects, it does not conform to the innovative and transitional picture advanced in many previous interpretations of the Wolfenden Committee and its aftermath.     

Reinforced Concrete Exterior Waffle Flat Plate-Column Connections Subjected to Lateral Earthquake Loading

An experimental investigation of an exterior waffle flat plate-column connection subjected to combined gravity and cyclic lateral loading is presented. The test model was designed according to construction practices used over ten years ago in the Mediterranean area. Test results are discussed in conjunction with previous studies on flat-slab connections and ACI 318–05 code idealizations. The specimen exhibited a “strong column-weak plate” mechanism, whose behavior was controlled by the torsion cracks. First yielding and failure occurred at 1% and 5.5% drift-ratios, respectively. The results show that ACI 318–05 code significantly underestimates strength; as an alternative, a simple model is proposed.     

Analytical Collapse Study of Lightly Confined Reinforced Concrete Frames Subjected to Northridge Earthquake Ground Motions

Review of older non seismically detailed reinforced concrete building collapses shows that most collapses are triggered by failures in columns, beam-column joints, and slab-column connections. Using data from laboratory studies, failure models have previously been developed to estimate loading conditions that correspond to failure of column components. These failure models have been incorporated in nonlinear dynamic analysis software, enabling complete dynamic simulations of building response including component failure and the progression of collapse. A reinforced concrete frame analytical model incorporating column shear and axial failure elements was subjected to a suite of near-fault ground motions recorded during the 1994 Northridge earthquake. The results of this study show sensitivity of the frame response to ground motions recorded from the same earthquake, at sites of close proximity, and with similar soil conditions. This suggests that the variability of ground motion from site to site (so-called intra-event variability) plays an important role in determining which buildings will collapse in a given earthquake.     

Mourning Geography: A Punctum,Strathclyde and the Death of a Subject

Abstract

This article documents the formal consultation held at the University of Strathclyde in 2011 which concluded with a decision to withdraw the geography programme from the academic curriculum. In examining the remains of this consultation, the article offers an understanding of the reactions of staff and students to the proposed closure through the theoretical work on mourning by Roland Barthes and Jacques Derrida. With use of the notions of punctum and studium in particular, it tracks the discursive location, if not definition, of what was and is poignant about geography at this higher education institution.     

New Multilateral Development Banks and Green Lending: Approaching Scalar Complexities in the Global South

Newly established multilateral development banks promote green finance and support a green transition in the global South. This article examines the new multilateral development banks using a dynamic view and documents the projects and lending preferences of New Development Bank (NDB) in Brazil and Asian Infrastructure Investment Bank (AIIB) in Turkey. While AIIB and NDB have made it easier for global South actors to access infrastructural investment funding and are committed to expanding green lending, their commitment rests on the use of country systems and national financial intermediaries. This results in extending loans for projects with significant risk and ignoring the broader connections of the projects to the environmentally hazardous strategies of capital accumulation. Despite their strong green discourse, their design and the way their mandates have been interpreted render new multilateral development banks prone to business as usual.     

《中国共产党历史》第二卷对中华人民共和国史研究的意义

2011年出版的《中国共产党历史》第二卷记载了中国共产党自1949年10月中华人民共和国成立至1978年12月中共十一届三中全会召开这段历史,该书不仅是党史研究的一项重大成果,而且对国史研究也具有重要意义:为正确把握新中国前29年历史的重大问题提供了基本参照;披露了140多件文献档案,整理了一系列统计数据,为深入研究新中国前29年的历史提供了有价值的新史料;其编写方法为研究编纂新中国前29年的历史提供了有益的借鉴和启示。     

The retreat from neoliberalism that was not: Australia’s Building the Education Revolution

This article examines the durability of neoliberalism in the face of crisis by analysing the Building the Education Revolution (BER), a key part of the Australian Labor Government’s stimulus measures in response to the global financial crisis in 2009. The fiscal stimulus measures enacted by governments in the aftermath of the crisis led many commentators to herald the end of neoliberalism. By examining the design of the BER, however, this article finds that one of the key policy tools of neoliberalism – the outsourcing of public sector capacity – was extended through such stimulus programs. The article argues that a materialist analysis of neoliberalism is better able to understand this phenomenon than the recent tendency to analyse neoliberalism in ideational terms.     

长城保护工程勘察设计工作回顾性分析

本文通过对2000年以来长城保护方案及有关批复意见的系统梳理,重点从勘测、勘察、设计定位与保护原则、工程技术手段及设计文本与图纸等方面对目前勘察设计中存在的共性问题进行了系统分析;同时,根据不同结构类型的长城,还对现存主要病害和技术措施进行了抽样分析.在此基础上,本文从保护规划体系、立项审核、保护维修工作原则、勘察设计要求及项目实施与管理等方面提出了建议.     

The Shiʿa Afghan Community: Between Transnational Links and Internal Hurdles

This article aims to present a political analysis of the relationship between the Shi?a community in Afghanistan and the new political system that emerged after the US military intervention of 2001. In light of the sectarian conflicts in the greater Middle East and the connection between South West Asia and the Syrian war since 2011, this article illustrates the limits of the social empowerment of the Shi?a communities in Afghanistan. The article outlines the internal religious scene and the connections between āyatollāhs (marāje?), mainly from Iran or Iraq, and Afghan Shi?ite believers. It also examines how the Afghan Shi?ite community differs from those of Iran and Iraq.     

Neo-Colonialism Reconsidered: A Case Study of East Africa in the 1960s and 1970s

A former major base of British colonialism, East Africa, has served as one of the testing grounds for what has been referred to as neo-colonialism. According to Kwame Nkrumah, neo-colonialism indicates that although ‘in theory’, a colony attains independence, ‘[i]n reality its economic system and thus its political policy is directed from outside’ (Neo-Colonialism: The Last Stage of Imperialism. London: Panaf Books, 2004 [1965]). This article challenges this image of neo-colonialism. Based on British documents of the late 1960s and early 1970s, most of which have become available to the public only in the last decade, and sources in East African libraries, it casts new light on British external relations with East Africa in the heady days of independence. These documents demonstrate that the new states of East Africa enjoyed a substantial degree of autonomy, that Britain's development aid was inconsistent and that Britain's involvement in the affairs of its former colonies was reluctant. These accounts reveal that the impact of British policy on newly independent states was actually limited, and thus the nature of Britain's relationship with its ex-colonies and the discourse of neo-colonialism are debatable.     

Toronto,an American city: Aspects of its postwar planning, 1940–1960

Toronto is conventionally considered quite unlike “American cities.” This article does not fundamentally challenge this convention, but does suggest that differences between Toronto and American cities may be overdrawn and that Toronto may have more American elements than is generally recognized. The evidence presented in this study comes from three episodes in Toronto’s postwar planning history: creation of an ambitious postwar master plan in 1943–44, formation of metropolitan government and planning in the mid-1950s, and the design and construction of the iconic suburban neighborhood of Don Mills also in the 1950s. All three show strong American planning connections. The article then offers some reasons why these American planning ideas did not produce an “American city,” and concludes by challenging the view that it is due to Canada having a fundamentally different urban culture.     

Reflections on Attending the WAC Ethics Committee Workshop

This short piece recalls my expectations for the Ethics Committee Workshop, reflects on how refreshing and stimulating it was to see all my expectations tumble, and concludes with further puzzlement about how to proceed. Supplementary abstract, written by Julie Hollowell: Joan arrived at Stanford with a specific interest in developing an International Code of Ethics with guidelines that would challenge archaeologists to carry out more responsible and ethical research abroad. She found that almost all of her preconceived ideas for such a Code were altered as a result of our discussions about the limitations of drafting a document specifying what was “good” or “bad” from a generalized perspective. The focus instead lay on the PROCESS of making ethical decisions, based on WAC principles, alternative ways of constructing an ethical outcome, and learning from case studies. She emphasizes that ultimately we will certainly want to weigh our suggestions for ethical-decision-making so that certain outcomes are favored over others and notes that this is where the application of social justice as a key organizing principle comes into play.     

Assessment of Perforated Steel Beam-to-Column Connections Subjected to Cyclic Loading

This article presents a study of fully fixed (welded) perforated beam-to-column connections, used as strengthening techniques to seismic-resistant design. The effect of using non-standard novel web opening configurations of variable depths and positions is investigated. The improvements on the structural behavior foreshadow the enhancements gained using these perforated members. It is concluded that using large isolated perforations is an effective way of improving the behavior of connections enhancing their ductility, rotational capacity and their energy dissipation capacity. Moreover, the connections with novel openings outperform the conventional ones; therefore, they can be suitably used in the aseismic design of steel frames.     

ISOLATING CONNECTIONS – CONNECTING ISOLATIONS

The varied and distinct ways we connect can facilitate or impose isolation, our own or someone else's. Different forms of isolation are themselves interconnected and sometimes enrich our connecting. The relation between isolation and connection, we argue, is one of complementarity, like Calvino's ‘two inseparable and complementary functions of life …syntony, or participation in the world around us … [and] focalization or constructive concentration.’ Solitude sought can enhance connections. Imposed isolation weakens connections in ways both obvious and subtle. This contrast between sought and imposed underscores the influence of hierarchy and socially produced inequities, excesses of which fragment the social ties that could constrain or diminish these same inequities. Deep inequity degrades the quality of both connections and isolation, at significant costs to our health, ecology, economy, cultural diversity, and political vitality. From this vantage point, we cull ways to improve our syntony and our focalization, fulfilling by expressing those shared egalitarian moral sentiments that motivate connections of solidarity partly in the interest of being “left alone”.     

A Guarded Courtship: Soviet Cultural Diplomacy in Iran from the Late 1940s to the 1960s

By bringing to bear previously unstudied Soviet archival documents and conducting firsthand interviews with former diplomats, the article traces the ways in which the Soviet Union sought out opportunities to reinvigorate deteriorated Soviet?Iranian ties through cultural organizations and events in Iran during the decades following World War II. A variety of Soviet cultural representatives—from wrestlers to classical musicians to scholars of Iranian literature—were marshaled for this effort, which bore unexpected fruit considering the modest expectations of the Soviet leadership, ideological differences between the two countries, and increasingly dominant US cultural projection. The connections between cultural ties and state goals, Iranian perceptions of Russia, and the Soviet/Russian sympathies of some members of the shah’s government are among sub-themes examined.