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.     

Childhoods past and present: anxiety and idyll in reminiscences of childhood outdoor play and contemporary parenting practices

ABSTRACT

Outdoor play is considered an essential aspect of a ‘proper childhood’. However, unsupervised outside play is declining, a decline attributed to parental anxieties about children’s safety. However what drives these anxieties and how this impacts on contemporary outdoor play is less clear. Our paper seeks to explore this through an analysis of adult narratives generated through digital map-making and forum discussion about where they played as children and where they would allow a child to play unsupervised now. Our analysis explores the nature of these narratives and pivotal moments in which adults articulated the disconnect between their own recollections of idyllic spatial freedom and the spatial restrictions they place on contemporary children. This offers a rich understanding of how parents navigate conflicting cultural imperatives on risk-avoidance and children’s rights to a ‘good’ childhood.     

Intercontinental Hybrid Simulation for the Assessment of a Three-Span R/C Highway Overpass

This paper presents hybrid simulations of a three-span R/C bridge among EU, US, and Canada. The tests involved partners located on both sides of the Atlantic with each one assigned a numerical or a physical module of the substructured bridge. Despite the network latency in linking remote sites located on the two sides of the Atlantic the intercontinental hybrid simulation was accomplished and repeated successfully, highlighting the efficiency, and repetitiveness of the approach. Adaptations, challenges, and limitations are discussed, focusing on the implications of network communication latency, the insensitivity of the sub-structuring arrangement, and the accuracy of the results obtained.     

受控冷冻灭虫法的风险控制

受控冷冻灭虫的关键在受控,受控指标包括冷冻温度、降温速度与冷冻时间,受控的目的是要达到彻底灭虫。冷冻温度与降温速度直接影响到被冷冻物品的形体安全,保障物品安全为前提的受控冷冻灭虫需要管控风险。基于文献分析、相关问题的调研与理论研究发现,温度不够低、降温速度不够快以及灭虫时间过短都会造成灭虫不彻底的风险。极端低温与快速降温带来物品的损伤与被冷冻物品的材料性质相关,将在极端低温与热冲击力下必然会损坏的材料排除在冷冻灭虫的许可范围之外,科学地选择冷冻温度与加强冷冻灭虫过程管控,可使受控冷冻灭虫化险为夷,即以保证藏品安全为前提的彻底灭虫。     

馆藏文物预防性保护风险管理的实践与思考——以上海博物馆为例

馆藏文物预防性保护工作在我国经过了二十余年的系统性研究和应用实践,已经取得了重大进步。近年来,上海博物馆在预防性保护工作中引入风险管理理念,通过明确环境信息、风险评估、风险应对和监督检查的流程,降低文物风险,保障文物安全。本文以上海博物馆的两个临时展览为例,从环境信息统计分析、湿度阈值设定与调控策略选择、材料环境安全性评估、展柜密封性能要求等方面阐述了馆藏文物预防性保护风险管理工作的应用实践和研究思考。     

Distributed Tuned Mass Dampers for Multi-Mode Control of Benchmark Building under Seismic Excitations

The effectiveness of the multi-mode control of seismically excited building installed with distributed multiple tuned mass dampers (d-MTMDs) is investigated by comparing dynamic response with the other controllers, such as passive friction dampers, semi-active dampers, single tuned mass damper (STMD), and multiple tuned mass dampers (MTMDs-all.top), both installed at the top of the building, and arbitrarily distributed MTMDs (ad-MTMDs). It is concluded that the d-MTMDs exhibit improved performance as compared with the STMD, MTMDs-all.top, and ad-MTMDs. The d-MTMDs are also convenient to install owing to the reduced space requirements, being placed at various floors.