Moinhos de água e vento : um património esquecido

Os moinhos, cujas primeiras construções remontam a 85 a.C., foram durante vários séculos a única forma de moagem. Os moinhos foram e são um exemplo de soluções de aproveitamento energético equilibrado e respeito pela natureza. Em Portugal os moinhos de água e vento foram maioritariamente utilizados para a moagem de cereais. Adicionalmente, a sua presença no território nacional tornaram estas pequenas construções um forte elo de relações e tradições para as populações locais. Com a Revolução Industrial foram criados no Século XIX os primeiros sistemas mecânicos de moagem, levando gradualmente a um abandono e posterior esquecimento dos moinhos tradicionais. Por vezes, o abandono deste património é tão significativo que se perdeu completamente a identidade cultural, construtiva e funcional

Tube-jack testing for irregular masonry walls: first studies

One of the most well-known non-destructive methods for inspection and diagnosis in historical masonry walls is the flat-jack testing. Although it gives qualitative and valuable results about the local stress level and the deformability of the masonry material, when testing on irregular masonry walls, or walls with larger stone units, experimental and practical problems might occur, leading to inaccurate or useless results. In addition, the testing apparatus is labor, with difficulties in sawing task. Another limitation is the difficulty to test multi-leaves walls. To overturn these problems and to achieve more reliable information, an enhanced type of jacks is proposed in the paper. The new testing system consists of tube-jacks instead of the usual flat-jacks. As part of the preliminary research, analyses with FE models to simulate the differences between the conventional and the enhanced method are presented in the paper. The advantages and disadvantages of both methods are discussed and further research steps are presented

Seismic safety analysis of the old portuguese cathedral in Safi, Morrocco

The paper presents the main results of the safety analysis of the Safi Cathedral. First a general description of the cathedral and the restoration project are given. To assess the safety of the main arch of this cathedral after the restoration, a seismic line of thrust analysis was used. The results of this uncommon analysis for structures which face seismic hazard were then compared to the results obtained from a phased pushover analysis. The results of the seismic line of thrust analysis turned out more conservative than those of the finite element analysis, although in both cases the results depend on the modeling hypothesis.The authors would like to appreciate their gratitude to the ones who could make this work possible, namely the Portuguese Calouste Gulbenkian Foundation, which is funding the restoration project, the architect Joao Campos from the Calouste Gulbenkian Foundation who developed the architectonical project and is responsible for the intervention, and the engineer Antonio Ramos from R3R - Gabinete de Projectos Ltd., responsible for the structural rehabilitation project

Static and dynamic structural monitoring of the Santa Maria of Belém church, in Lisbon

The paper details two monitoring systems implemented in the main nave of Santa Maria of Belém Church of the Monastery of Jerónimos, in Lisbon. The monitoring systems are being installed to better understand the static and dynamic behavior of the structure, with the purpose of damage detection and the improvement of seismic resistance of the monument. In the paper, preliminary investigations, numerical non-linear analyses and the first dynamic modal identification analyses are described. Also the preliminary works for the monitoring systems are presented, including the points selected for observation, the discussion of the sensors technical characteristics, as well as preliminary inspection and diagnosis. The first results of the dynamic monitoring system are shown and the future developments on the systems are presented, aiming at a full integration of all adopted techniques.European-Indian Economic Cross Cultural Program - Contract ALA/95/23/2003/077-122

Avaliação da segurança de dois pavimentos em madeira

Apresentam-se nesta comunicação dois casos de estudo correspondentes à inspecção, avaliação e reforço de dois pavimentos de madeira. O primeiro corresponde a um pavimento da Câmara Municipal de Arcos de Valdevez, onde, após uma intervenção para a sua reabilitação, se realizou uma inspecção estrutural e um ensaio de carga para a avaliação da segurança do pavimento. O segundo pavimento corresponde ao do coro alto da igreja da N. Sr.a da Conceição do Instituto Monsenhor Airosa, em Braga, onde se levou a cabo uma inspecção estrutural, compreendendo um conjunto de ensaios não-destrutivos, apresentando-se no final algumas recomendações para a protecção da madeira e reforço do sistema estrutural

Modeling and vulnerability of historical city centers in seismic areas : a case study in Lisbon

Historical city buildings are an integral part of the built heritage to be preserved, and their safety is a primary requirement in seismic areas. Collapse of ancient masonry buildings due to seismic actions occur mostly due to overturning of the perimeter walls. This paper addresses the issue of seismic analysis and vulnerability of historical city centers, with a specific case study: the 18th century downtown part of Lisbon, Portugal. The finite element method was adopted for a number of different analyses, introducing non-linear behavior of the materials. From the analysis, the following issues have been addressed: (a) seismic vulnerability of this type of constructions; (b) influence of the group of buildings on the seismic behavior of the individual buildings that compose a single compound; and (c) methodology for action. It is believed that the conclusions obtained with respect to the seismic assessment of masonry buildings can be extrapolated for the wide variety of historical city centers

Dynamic identification and monitoring of cultural heritage buildings

Preservation of architectural heritage is considered a fundamental issue in the cultural life of modern societies. This heritage is accumulating damage due to deterioration of materials, repeated loading and exceptional events. This means that conservation, repair and strengthening are often necessary. In this process, monitoring and non-destructive testing play a major role, providing information on the building condition and existing damage, and allowing to define adequate remedial measures. Dynamic based methods are an attractive tool because they are non-destructive and are able to capture the global structural behavior. The present paper focuses on three main aspects related to dynamic identification and monitoring: (a) exploring damage in masonry structures at an early stage by vibration measurements, using one arch model constructed in the laboratory. Progressive damage was induced in the arch and sequential modal identification analysis was performed at each damage stage, aiming at finding adequate correspondence between dynamic behavior and internal crack growth. The dynamic based methods allowed detecting and locating the damage; (b) two complex case studies of modal and structural identification of monuments using conventional sensors. Operational modal analysis was used to estimate the modal parameters, followed by statistical analysis to evaluate the environmental effects on the dynamic response. The aim is to explore damage assessment in masonry structures at an early stage by vibration signatures, as a part of a health monitoring process; (c) finally, a comparison between commercial wireless based platforms and conventional wired based systems is presented for a laboratory specimen and a structural element from a 15th century building

Recent developments in vibration analysis of historic and masonry structures: damage detection and wireless sensor networks

Preservation of architectural heritage is considered a fundamental issue in the cultural life of modern societies. This heritage is accumulating damage due to deterioration of materials, repeated loading and exceptional events. This means that conservation, repair and strengthening are often necessary. In this process, monitoring and non-destructive testing play a major role, providing information on the building condition and existing damage, and allowing to define adequate remedial measures. Dynamic based methods are an attractive tool because they are non-destructive and are able to capture the global structural behaviour. The present paper focuses on different aspects related to vibration analysis, namely exploring damage, environmental effects on the dynamic response, a comparison between commercial wireless based platforms and conventional wired based systems, and a novel wireless based system

Dynamic identification and monitoring of St. Torcato Church

The paper is related to the San Torcato Church, in Guimarães, Portugal. At the moment, the church has significant structural problems due to soil settlements. Cracks can be observed on the main and the lateral façades, the bell-towers are leaning, and the arches in the nave exhibit a failure mechanism with cracks and vertical deformations. Non-stabilized phenomena are present in the structure. To stabilize the damage, a structural intervention is planned to occur soon and the church is already monitored to follow the intervention. The paper clearly presents the problem with emphasis to the dynamic analysis carried out before the structural strengthening, namely: the experimental tests with output-only techniques for frequencies, damping and mode shapes estimation, FE model updating analysis and dynamic monitorin