Review of Out-of-Plane Seismic Assessment Techniques Applied To Existing Masonry Buildings

ABSTRACT

Observations after strong earthquakes show that out-of-plane failure of unreinforced masonry elements probably constitutes the most serious life-safety hazard for this type of construction. Existing unreinforced masonry buildings tend to be more vulnerable than new buildings, not only because they have been designed to little or no seismic loading requirements, but also because connections among load-bearing walls and with horizontal structures are not always adequate. Consequently, several types of mechanisms can be activated due to separation from the rest of the construction. Even when connections are effective, out-of-plane failure can be induced by excessive vertical and/or horizontal slenderness of walls (length/thickness ratio). The awareness of such vulnerability has encouraged research in the field, which is summarized in this article. An outline of past research on force-based and displacement-based assessment is given and their translation into international codes is summarized. Strong and weak points of codified assessment procedures are presented through a comparison with parametric nonlinear dynamic analyses of three recurring out-of-plane mechanisms. The assessment strategies are marked by substantial scatter, which can be reduced through an energy-based assessment.     

Modernist Unreinforced Masonry (URM) Buildings of Barcelona: Seismic Vulnerability and Risk Assessment

The main objective of this work is to assess the vulnerability and seismic risk of typical existing modernist unreinforced masonry (URM) modernist buildings and aggregates situated in the Eixample district of Barcelona, part of the architectural heritage of the city. The context of the analysis is the methodology proposed by the Risk-UE project. The buildings are characterized by their capacity spectrum and the earthquake demand is defined by the 5% damped elastic response spectrum, considering deterministic and probabilistic earthquake scenarios. A discussion addresses the basis of the seismic damage states probabilities and the calculated damage index. An important research effort has been focused on the buildings modeling. All the architectural elements and their mechanical properties have been studied and evaluated accurately. It has been evidenced that a detailed and complete knowledge of all the structural elements existing in this type of buildings influence directly their behavior and hence the calculations and the results. The analysis of the isolated buildings and of the aggregate building has been performed for both mentioned seismic scenarios. Finally, a complete discussion of the results is included.     

Blueing business as usual in the ocean: Blue economies,oil, and climate justice

Oceans are increasingly looked toward for their contribution to addressing climate change. These so-called ocean-based climate “solutions” often fall under the umbrella of the “blue economy,” a term used to refer to new ways of organizing ocean economies to provide equitable economic and environmental benefits. Yet, thus far the literature exploring blue economies and blue economy governance has largely overlooked or downplayed its equity and justice roots and implications, including how blue economies are embedded in multiple scales of environmental injustices. This is particularly important when blue economies include offshore oil production. The purpose of this paper is to both emphasize the need and provide an approach to incorporate justice and equity—specifically climate justice—into blue economy planning and scholarship. We build on conceptualizations of blue economies as assemblages to draw attention to the global reach of climate impacts associated with oil that are often overlooked or ignored at sites of production and through regional governance. We argue that greenhouse gas emissions from the life cycle of oil should be included in policies and planning (including blue economy planning) at sites of production, but that this must also incorporate underlying power structures that lead to uneven impacts and climate injustice. We look at environmental assessments as a regional governance tool that could be used to shape opportunities and openings to organize blue economies differently. To illustrate these points, we look at how environmental assessments are playing (and could play) a role in enacting and shaping Newfoundland and Labrador's blue economy.     

县域循环经济与产业协同发展成熟度评价指标体系研究

循环经济是一个全新的发展理念,反映出可持续发展的实质性内容,也是实现县域经济产业协同发展的重要保障。评价某个县域发展状况是一个系统工程,目前在国内外尚没有一个完整的评价体系。本文试图探究建立一套科学合理的评价指标体系,从而对中国县域经济产业协同发展成熟度作出总体的评价。     

Underwater Archaeology on Foot: a Systematic Rapid Foreshore Survey on the North Kent Coast, England

Foreshore archaeology can be considered 'underwater archaeology on foot', because it is possible to investigate the archaeological heritage at low tide without the need for diving. Rising sea-levels, increasing coastal erosion and the loss of important foreshore environments make immediate action necessary. In 2005, Wessex Archaeology was commissioned by Kent County Council, supported by English Heritage, to continue a Rapid Coastal Zone Assessment Survey on the North Kent Coast as part of a project started in 2001. In four weeks 378 monuments were updated and 198 new monuments recorded, among them a submerged forest, a trackway, several fish-traps and shipwrecks.
© 2007 The Authors     

Managing flood risk in the UK: towards an integration of social and technical perspectives

In recent years, an apparent increase in the frequency and severity of floods in the UK has led to growing concerns about societal exposure and vulnerability to flooding, particularly in the context of climate change, floodplain development and changing insurance practices. Despite the important link between assessments of exposure to flooding (hazard assessments) and issues of societal vulnerability, this link has rarely been explored in detail and has often been reflected in policy terms by a highly technocratic approach to flood risk management. Indeed, more comprehensive studies have usually favoured rigid and deterministic definitions of vulnerability, in keeping with the wider technocratic paradigm pervading management institutions. In an attempt to redress the balance, this paper considers the role of hazard assessment and issues of societal vulnerability as mutually informative debates and advocates a movement away from the technocratic ideals currently favoured in the UK.     

理性地认识和思考20世纪六七十年代的“全国大备战”

在新中国的历史上 ,曾经进行过一场声势浩大的全国性战争准备。这次战备 ,是新中国党和国家领导人面对当时严峻的国家安全环境的必然反应 ,其决策的正确性不容置疑。这次战备有得有失 ,增强了国防实力 ,提高了新中国的国际地位 ,有效地维护了国家安全 ,但同时也给国家经济发展和军队现代化建设带来一定的不良影响。汲取这次战备的经验和教训 ,对做好新时期的军事斗争准备不无裨益。     

中小型高新技术企业人才甄选测评实用方法之探析

高新技术企业大多以技术专长为主的技术型管理者为主导,他们是企业的核心力量。然而,采用什么样的人才甄选测评方法,则是当前研究的重要课题。本文针对中小型高新技术企业岗位内容的变化情况,提出建立一套可操作性强和简便有效的人才甄选测评方法。该方法包括建立测评体系、岗位跟踪调查与分析、测评结果的评价和甄选等。     

浅论多媒体技术在教学中的应用

多媒体技术在现代教学工作中发挥着重要作用,与传统教学相比具有许多优势。然而,当前在多媒体教学工作中却存在着一些观念上的“误区”。对此,笔者认为,应纠正错误认识和不恰当的教学方式,采用科学的教学方法,以更好地发挥多媒体技术在教学中的作用。     

印谱古籍中的印油老化研究

存世印谱中比较常见的一类病害是印蜕中印油老化导致的渗化问题。研究表明,印油渗化不仅会在印蜕四周形成黄色或棕色的油渍,而且会导致纸张pH值降低,影响印谱的长久保存。通过对印泥中常用的蓖麻油、菜籽油、茶油、调和印油等六种油脂进行模拟老化实验,发现油脂老化后普遍存在变色、pH值下降和渗化问题。采用气相色谱-质谱联用技术分析老化前后的油脂样品,发现油脂在老化过程中,不饱和脂肪酸含量降低,饱和脂肪酸占比增加,并形成了壬二酸等脂肪族羧酸。油脂老化过程中的成分变化,导致了变色、酸化、渗化等一系列问题。在印谱实物样品中也发现了饱和脂肪酸。在印谱的保护工作中,应对油脂的老化进行有针对性的处理。