Investigation Techniques for the Seismic Response Assessment of Buildings Located in Historical Centers

ABSTRACT

It is an acknowledged fact that historical centers, given its significance from the cultural and architectural viewpoint, bring further challenges in terms of maintenance planning, survey, and safety assessment. The preparation of an adequate investigation plan and the extent of data to be collected is highly reliant on many aspects, such as the category of the architectonic asset, the importance of the heritage site, or the resources available, for example. In what regards the seismic response assessment of urban cultural heritage assets located in historical centers, the amount and detail of data also depend on this article, scale of assessment, and current state of conservation and occupation. Within this framework, this article provides an overview of the state of the art of investigation techniques currently used in survey operations, which are currently available for improving the knowledge level of urban cultural heritage assets within historical centers, as a supporting tool for the seismic response assessment of such singular assets. Finally, acknowledging the lack of accuracy when evaluating the seismic response of an asset enclosed in aggregate as an isolated structure, this article also focuses on the identification of the main particularities inherent to buildings enclosed in aggregate.     

Emergent Complexity,Changing Landscapes,and Spheres of Interaction in Southeastern South America During the Middle and Late Holocene

Newly created academic programs at Brazilian universities have provided the impetus for new archaeological projects in southeastern South America during the last two decades. The new data are changing our views on emergent social complexity, natural and human-induced transformation of the landscape, and transcontinental expansions and cultural interactions across the Río de la Plata basin during the Middle and Late Holocene. We concentrate on six major archaeological traditions/regions: the Sambaquis, the Pantanal, the Constructores de Cerritos, the Tupiguarani, the Southern Proto-Jê, and the middle and lower Paraná River. Diverse and autonomous complex developments exhibit distinct built landscapes in a region previously thought of as marginal compared with cultural developments in the Andes or Mesoamerica. The trajectories toward increased sociopolitical complexity flourished in very different and changing environmental conditions. While some groups were pushed to wetland areas during a drier mid-Holocene, others took advantage of the more humid Late Holocene climate to intensively manage Araucaria forests. The start of the second millennium AD was a critical period marked by an increased number of archaeological sites, the construction of ceremonial architecture, and the intensification of landscape transformation; it also was marked by the rapid expansion of influences from outside the La Plata basin. The Amazonian Tupiguarani and Arawak newcomers brought with them significant changes in technologies and social and political structures, as well as novel landscape management practices.     

Simulation of Shake Table Tests on Out-of-Plane Masonry Buildings. Part (IV): Macro and Micro FEM Based Approaches

ABSTRACT

This article presents a study on the out-of-plane response of two masonry structures without box behavior tested in a shaking table. Two numerical approaches were defined for the evaluation, namely macro-modeling and simplified micro-modeling. As a first step of this study, static nonlinear analyses were performed for the macro models in order to assess the out-of-plane response of masonry structures due to incremental loading. For these analyses, mesh size and material model dependency was discussed. Subsequently, dynamic nonlinear analyses with time integration were carried out, aiming at evaluating the collapse mechanism and at comparing it to the experimental response. Finally, nonlinear static and dynamic analyses were also performed for the simplified micro models. It was observed that these numerical techniques correctly simulate the in-plane response. The collapse mechanism of the stone masonry model is in good agreement with the experimental response. However, there are some inconsistencies regarding the out-of-plane behavior of the brick masonry model, which required further validation.     

Out-of-Plane Seismic Response of Unreinforced Masonry Walls: Conceptual Discussion,Research Needs,and Modeling Issues

ABSTRACT

Modeling unreinforced masonry walls, subjected to seismic loads applied normal to their plane, has received much attention in the past. Yet, there is a general lack of conformance with regard to what aspects of seismic response a computational model should reflect. Boundary conditions are certainly an important aspect, as the response can involve two-way bending or just one-way bending and, in the second case, along vertical or horizontal directions. In this respect, flexural restraint of wall intersections can be significant in addition to size and placement of openings. Moreover, in-plane damage can modify the boundary conditions and the overall out-of-plane performance. Proper modeling of actions is also relevant, as they can be a result of distortions imposed upon wall elements and/or inertial forces along the span of a wall. Axial forces can markedly affect the out-of-plane response of the wall, particularly vertical compressive forces, which can enhance out-of-plane strength. The outcome of static verifications can be more conservative than that of dynamic analyses, but the latter are much more complex to carry out. These topics are discussed with reference to previous research, observations in the field and in the laboratory, as well as numerical analyses on three-dimensional models.     

The smelting quarter of Valencina de la Concepción (Seville,Spain): the specialised copper industry in a political centre of the Guadalquivir Valley during the Third millennium BC (2750–2500 BC)

The first specialized copper industry of the Iberian Peninsula was developed at the start of the Third millennium BC with the appearance of mining-metallurgical settlements in its main mining district (the Pyrite Belt of the south-western). Between 2750 and 2500 BC, however, and right at the centre of the Guadalquivir Valley, the great farming settlements that ranked the territory developed a new level of metallurgic intensification with the creation of the first industrial quarters. As a way of explaining this new situation, we present the results of the systematic research (microspatial analysis; radiocarbon dating; petrologic, geochemical, metallographic and isotopic study of minerals, slag and products, …) carried out in one of them, the one developed in the main and largest political centre of the Guadalquivir Valley during the first half of the Third millennium BC: Valencina de la Concepción (Seville, Spain).     

Experimental Out-Of-Plane Behavior of Brick Masonry Infilled Frames

ABSTRACT

The vulnerability of masonry infills within reinforced concrete (rc) frames under out-of-plane loading induced by earthquakes has been observed in several past earthquakes through severe damage and often total collapse. Although the infill panels are assumed as non-structural elements, their damage or collapse is not desirable, given the possible consequences in terms of human life losses and repair or reconstruction costs.

Therefore, it is important to gather better insight on the out-of-plane behavior of existing infills so that strengthening guidelines can be derived. In this scope, the main objective of this study is to analyze the out-of-plane experimental behavior of masonry infilled frames that are characteristic of Portuguese buildings and can be seen in other south European countries. In the experimental study carried out, different parameters affecting the out-of-plane response of infilled frames were considered, namely, workmanship, existence of openings and prior in-plane damage. The experimental program was designed to test six half-scale specimens. The out-of-plane loading was applied uniformly to the brick infills by means of an airbag to simulate the effect of earthquakes.     

Spatial and temporal dynamics of the urban heat island effect in a small Brazilian city

This study examined the spatial and temporal patterns of the canopy layer urban heat islands (UHI_UCL) in a small city in southeastern Brazil using the local climate zone (LCZ) system. We analysed the influence of weather conditions, LCZs characteristics, and local surface relief on the UHI_UCL magnitudes. Mobile traverses were used to measure air temperatures during representative nights of wet and dry seasons. Daily maximum magnitudes were observed in compact classes (LCZs 3 and 7) under ideal weather conditions (dry, clear skies, and calm) and higher anthropogenic heat release (weekdays). Seasonal effects on LCZ thermal differences were negligible. The peripheral landscapes were warmer than the city centre in both seasons. Among the warmer areas in the city, magnitudes in compact LCZs 3 and 7 were consistently higher than in LCZ 6. In general, representative sites of the main ‘built’ LCZs in the study area exhibit similar inter-zone temperature patterns to those reported for cities of different sizes from tropical and midlatitude regions. Thermal contrasts of ΔT_{LCZ 3 − D} in the study area reveal significant evidence that small cities can have as strong heat islands as bigger cities. These findings highlight the importance of the LCZ system to identify the main controlling factors driving such thermal differences and the need to extend the application of this approach in other South American cities to yield systematic data of UHI_UCL for urban planning given the coming challenges of climate change over the region.     

Iron Age Saunas of Northern Portugal: State of the Art and Research Perspectives

Special buildings used as saunas have been found in certain large hillforts in the north of Portugal and in the Cantabrian coastal area of Asturias and Galicia in Spain. The principal aim of this study is to highlight the importance of these buildings in the archaeology and art of the European Iron Age, where they are very rarely mentioned. Two approaches are developed: in Parts 1 and 2, we explain the structure of the buildings, their function, and the current debate surrounding their dating. In Parts 3 and 4, further analyses are developed on their position in the landscape, associating the saunas with the public life of the hillforts, and on the decorative structure of the pedras formosas (‘beautiful stones’) found in some of them, and their relation to certain artistic trends in so‐called Celtic art.