排序方式: 共有93条查询结果,搜索用时 62 毫秒
21.
Nuno Mendes Alexandre A. Costa Paulo B. Lourenço Rita Bento Katrin Beyer Gianmarco de Felice 《International Journal of Architectural Heritage》2017,11(1):59-71
ABSTRACTEarthquakes cause severe damage to masonry structures due to inertial forces acting in the normal direction to the plane of the walls. The out-of-plane behavior of masonry walls is complex and depends on several parameters, such as material and geometric properties of walls, connections between structural elements, the characteristics of the input motions, among others. Different analytical methods and advanced numerical modeling are usually used for evaluating the out-of-plane behavior of masonry structures. Furthermore, different types of structural analysis can be adopted for this complex behavior, such as limit analysis, pushover, or nonlinear dynamic analysis.Aiming to evaluate the capabilities of different approaches to similar problems, blind predictions were made using different approaches. For this purpose, two idealized structures were tested on a shaking table and several experts on masonry structures were invited to present blind predictions on the response of the structures, aiming at evaluating the available tools for the out-of-plane assessment of masonry structures. This article presents the results of the blind test predictions and the comparison with the experimental results, namely in terms of formed collapsed mechanisms and control outputs (PGA or maximum displacements), taking into account the selected tools to perform the analysis. 相似文献
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Alexandre Oliveira Tavares Mário Monteiro Pedro Pinto Santos 《European Planning Studies》2019,27(7):1432-1459
Small and medium-sized cities represent the backbone of the European territory, promoting cohesion and an economic base for development. The study compares the spatial and temporal trajectories of land use in three small/medium-sized cities located in central Portugal, between 1958 and 2011. The cities of Viseu, Leiria and Castelo Branco were chosen because they are located in different urban sub-systems and because of the different factors that frame their alterations in land use, occupation and consequent urban development. The research evaluates the transformations, supported by indicators to explain the spatial dynamics of losses and gains and a principal component analysis compares the land-use trajectories for the three cities. The general results reveal an increase from the central part of the study areas to the periphery, contrasting with a continuous decrease of the agricultural parts, illustrating peri-urbanization and rururbanization processes. The study allows identification of the dynamics in the three analysed areas, highlighting the different rhythms of change and relating them to the particularities that exist in each city. The methodology represents an advantage for the analysis and evaluation of territorial dynamics related to land-use change, and made possible the identification of the different forces. 相似文献
24.
Fernando Peña Paulo B. Lourenço Alfredo Campos-Costa 《Journal of Earthquake Engineering》2013,17(6):953-979
This article describes the dynamical behavior of free-standing block structures under seismic loading. A comprehensive experimental investigation has been carried out to study the rocking response of four single blocks of different geometry and associations of two and three blocks. The blocks, which are large stones of high strength blue granite, were subjected to free vibration, and harmonic and random motions of the base. In total, 379 tests on a shaking table were carried out in order to address the issues of repeatability of the results and stability of the rocking motion response. Significant understanding of the rocking motion mechanism is possible from the high quality experimental data. Extensive experimental measurements allowed to discuss the impulsive forces acting in the blocks and the three-dimensional effects presented in the response. 相似文献
25.
Germaine Paulo Walsh 《Perspectives on Political Science》2013,42(1):15-26
Abstract Blitz argues for the necessity and possibility of political philosophy by uncovering its origins in the thought of Plato. By tracing its emergence from the political and moral, Blitz explains the nature of philosophy. 相似文献
26.
A Multiobjective Approach to Locate Emergency Shelters and Identify Evacuation Routes in Urban Areas 总被引:2,自引:0,他引:2
Luís Alçada-Almeida Lino Tralhão Luís Santos João Coutinho-Rodrigues 《Geographical analysis》2009,41(1):9-29
Evacuation planning is an important component of emergency preparedness in urban areas. The number and location of rescue facilities is an important aspect of this planning, as is the identification of primary and secondary evacuation routes for residents to take. This article introduces a multiobjective approach to identify these aspects of evacuation planning. The approach incorporates a multiobjective model into a geographical information systems–based decision support system that planners can access via the Internet. The proposed approach is demonstrated with a case study for the City of Coimbra, Portugal, for evacuation during major fires. Although presented in this context, this approach is applicable to other emergency situations such as earthquakes, floods, and acts of terrorism. 相似文献
27.
Joeri Kaal Antonio Martínez Cortizas Eileen Eckmeier Manuela Costa Casais Manuel Santos Estévez Felipe Criado Boado 《Journal of archaeological science》2008
The colluvial soils of Galicia (NW Spain) are records of Holocene environmental change. In spite of the omnipresence of charcoal fragments in these soils, the effect of fires on the development of the Galician landscape and the potential role of past societies are poorly understood. 相似文献
28.
International R&D Cooperation between Low-tech SMEs: The Role of Cultural and Geographical Proximity
Aurora A. C. Teixeira Paulo Santos Ana Oliveira Brochado 《European Planning Studies》2008,16(6):785-810
Although there is a considerable amount of empirical evidence on inter-firm collaborations within technology-based industries, there are only a few works focussing on R&D cooperation by low-tech firms, especially small and medium-sized enterprises (SMEs). Providing further and new evidence based on a recently built database of CRAFT projects, this study analyses the relationship between technology and proximity in international R&D networks using HOMALS and statistical cluster techniques. The resulting typology of international cooperative R&D projects highlights that successful international cooperative R&D projects are both culturally/geographically closer and distant. Moreover, and quite interestingly, geographically distant projects are technologically more advanced whereas those located near each other are essentially low-tech. Such evidence is likely to reflect the tacit-codified knowledge debate boosted recently by the information and communication technology (ICT) “revolution” emphasized by the prophets of the “Death of Distance” and the “End of Geography”. 相似文献
29.
Over more than a century, several proposals have been made on the composition and technical features of the pictorial recipes used by Levantine prehistoric painters. In this paper all these proposals are surveyed and tested through systematic experiments to determine the technical affordance of pigments and binders in different pictorial recipes. Experimental results were then used as independent analytical parameters employed as diagnostic criteria to systematically study an archaeological sample of nine sites located in the Maestrazgo region (Spain) and their surroundings. Results reveal that out of 112 experimental recipes, only 16 afforded the production of paintings technically similar to Levantine rock art. 相似文献
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Angelo Gaetani Giorgio Monti Paulo B. Lourenço Giancarlo Marcari 《International Journal of Architectural Heritage》2016,10(7):841-856
The history of cross vaults began almost 2,000 years ago with a widespread use during the Middle Ages and Renaissance, becoming nowadays one of the most diffused and fascinating structural typologies of the European building cultural heritage. However, conversely to the undeniable excellence achieved by the ancient masons, the structural behavior of these elements is still at the center of the scientific debate. In this regard, with the aim of reviewing the knowledge on this subject as a concise and valuable support for researchers involved in conservation of historical buildings, with a focus on design rules and structural analysis, the present study firstly introduces the cross vaults from a historical perspective, by describing the evolution of the main geometrical shapes together with basic practical rules used to size them. Then, the article deals with the subsequent advancements in structural analysis methods of vaults, until the development of modern limit analysis. 相似文献