scholarly journals Proposta de consolidação estrutural da Igreja de Nossa Senhora do Monte do Recôncavo

2014 ◽  
Vol 4 (3) ◽  
pp. 228-236
Author(s):  
M. Oliveira ◽  
R. Muñoz ◽  
A. Magalhães
Keyword(s):  
Eighteenth Century ◽  
Historic Buildings ◽  
Structural Elements ◽  
Roof Structure ◽  
Intervention Measures ◽  
Wood Beams ◽  
Non Destructive

RESUMOA Igreja de Nossa Senhora do Monte, construída na Bahia, Brasil, provavelmente no início do século XVIII, está localizada em São Francisco do Conde, no Recôncavo Baiano. Atualmente, o edifício encontra-se em estado geral de eversão, principalmente em relação à cobertura e ao desaprumo de paredes. Este trabalho tem como objetivo propor medidas de intervenção patrimonial para estabilização dos referidos elementos construtivos, considerando a manutenção da mesma lógica estrutural existente. Como resultados, serão apresentados: detalhe de reforço do sistema estático das tesouras de linha baixa da nave principal; sumário do projeto de substituição dos atuais barrotes de madeira por vigas metálicas; e detalhe do atirantamento da abóbada do fundo da capela-mor. Ressalta-se a importância deste trabalho de estabilização como metodologia a ser adotada em outras edificações históricas, uma vez que contempla intervenções não destrutivas, relevantes para sítios que contam com patrimônios de significativo valor histórico e cultural.Palavras chave: consolidação; patrimônio; estrutura; reforço.ABSTRACTThe Church of Nossa Senhora do Monte, built in Bahia, Brazil, probably in the eighteenth century, is located in São Francisco do Conde, in the Recôncavo. Currently the building is in a deplorable state of degradation, especially in terms of the roof and stability of the walls. This work proposes intervention measures to stabilize the said structural elements while taking into consideration and respecting the existing structural logic. The following results will be presented: detail of the reinforcement of the wood roof structure of the nave; summary of the project for the replacement of existing wood beams by metal ones; and finally the proposal to repair the vault after the presbytery. This paper emphasizes the importance of this stabilization work as a methodology to be adopted in other historic buildings, since it suggests non-destructive interventions, relevant to sites that have assets of significant historical and cultural value.Keywords: consolidation; heritage; structure; strengthening.

Vibration-Based Crack Detection in L-Frames

2014 ◽  
Vol 658 ◽  
pp. 261-268
Author(s):  
Jean Louis Ntakpe ◽  
Gilbert Rainer Gillich ◽  
Florian Muntean ◽  
Zeno Iosif Praisach ◽  
Peter Lorenz
Keyword(s):  
Strain Energy ◽  
Crack Detection ◽  
Natural Frequencies ◽  
Vibration Modes ◽  
Structural Elements ◽  
Element Analysis ◽  
Accurate Localization ◽  
Mathematical Expressions ◽  
Measurement Results ◽  
Non Destructive

This paper presents a novel non-destructive method to locate and size damages in frame structures, performed by examining and interpreting changes in measured vibration response. The method bases on a relation, prior contrived by the authors, between the strain energy distribution in the structure for the transversal vibration modes and the modal changes (in terms of natural frequencies) due to damage. Using this relation a damage location indicator DLI was derived, which permits to locate cracks in spatial structures. In this paper an L-frame is considered for proving the applicability of this method. First the mathematical expressions for the modes shapes and their derivatives were determined and simulation result compared with that obtained by finite element analysis. Afterwards patterns characterizing damage locations were derived and compared with measurement results on the real structure; the DLI permitted accurate localization of any crack placed in the two structural elements.

Study of the residual imperfections using methods of probability theory

2021 ◽  
Vol 87 (9) ◽  
pp. 44-49
Author(s):  
D. A. Kuzmin
Keyword(s):  
Probability Theory ◽  
Generalized Equation ◽  
Structural Elements ◽  
Non Destructive Testing ◽  
Operational Control ◽  
Destructive Testing ◽  
Control Procedures ◽  
Non Destructive ◽  
A Current

Discontinuities in the products that occur during manufacture, mounting or upon operation can be missed during non-destructive testing which do not provide their complete detectability at a current level of the technology. Therefore, it is necessary to take into account that certain structural elements may have discontinuities of significant dimensions. We present the results of using the methods of probability theory in studying the residual imperfections that remains in the structure after non-destructive control and repair of the previously identified defects. We used the results of operational control of units carried out by ultrasonic and radiographic methods. We present a method for determining a multifactorial coefficient that takes into account the detectability of defects, the number of control procedures and the errors in the instrumentation and methodological support, as well as a generalized equation for the probability distribution of detecting discontinuities. The developed approach provides assessing of the level of damage to the studied objects, their classification proceeding from the quantitative data and determination of the values of postulated discontinuities for deterministic calculations. The results obtained can be used to improve the methods of monitoring NPP facilities.

scholarly journals Methodology for inspection of wood pathologie using ultrasonic pulses

CERNE ◽  
2012 ◽  
Vol 18 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Edgar Vladimiro Mantilla Carrasco ◽  
Amanda Rocha Teixeira
Keyword(s):  
Nondestructive Testing ◽  
Historic Buildings ◽  
Structural Elements ◽  
Timber Beam ◽  
Ultrasound Technique ◽  
Glued Laminated Timber ◽  
Overall Stability ◽  
Complementary Techniques ◽  
Wooden Structures

Awareness has been on the rise on the part of society about the importance of wooden structures, in particular historic buildings. This concern is reflected in continued maintenance of historic heritage and has been increasingly leading professionals working in the field of wooden structures to seek improved techniques for inspection of such structures. Methods involving nondestructive testing (NDT) are the most recommended for inspection, as they do not affect the relevant architecture and thus help maintain the integrity and originality of the building. Among the various existing NDT methods, a widespread and promising option is the ultrasound technique. This work introduces a methodology for inspection of wooden structural elements using ultrasonic pulses. The methodology was applied to a glued laminated timber beam with signs of decay on its interior. Ultrasound results helped map the damaged areas of the beam on a plane by using isochromatic patterns. The contribution of this work is a methodology to help investigate wood pathologies which, in combination with other complementary techniques, will allow more accurate and reliable evaluations of wooden structures, avoiding unnecessary replacement of sound structural elements mistakenly presumed to be damaged, or else ensuring maintenance of extremely deteriorated elements that would otherwise compromise the overall stability of the structure.

scholarly journals Assessment of Timber Roof Structures before and after Earthquakes

Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 528
Author(s):  
Nikola Perković ◽  
Mislav Stepinac ◽  
Vlatka Rajčić ◽  
Jure Barbalić
Keyword(s):  
Test Methods ◽  
Timber Structures ◽  
Destructive Testing ◽  
Policy Makers ◽  
Load Bearing ◽  
Existing Structures ◽  
Roof Structure ◽  
Before And After ◽  
Timber Roof Structures ◽  
Non Destructive

The global objective of sustainable development has been greatly directed toward the preservation of existing structures. Therefore, condition assessment and reconstruction of existing timber structures have been gaining importance in recent times. This is particularly evident on timber roofs whose elements are exposed to degradation, either because of rheological effects or due to the direct influence of moisture and biological factors. In case of accidental events, such as an earthquake, the question of the structure’s condition is essential for the condition of the entire building. In order to prove the load-bearing capacity and serviceability of existing structures, as well as to check the need for reconstruction, it is necessary to define crucial parameters that are influencing the condition of materials, elements, and systems. Although there are many non destructive testing methods, the frequency and scope of their use, as well as the decision-making approach, have not been defined. In the paper, non-destructive and semi-destructive methods frequently used for timber structures are explained. A systematic review of criteria to be used in the assessment of load-bearing timber structures in a seismic active area was the main objective of this paper as well as the illustration of non-destructive and semi-destructive test methods through a case study involving roof construction of a hundred-year-old building in Zagreb, Croatia. Pre- and post-earthquake inspection was made. The overall condition of the roof structure after two significant earthquakes can be assessed as satisfactory given that the observed system is a large-span and massive roof structure. The presented results and identification of typical damages after the earthquake are presented in order to facilitate policy makers and for the future implementation of development strategies in the renovation of the city.

Non-Destructive Tests and Bending Tests on Chestnut Structural Timber

2013 ◽  
Vol 778 ◽  
pp. 167-174 ◽  
Author(s):  
Beatrice Faggiano ◽  
Maria Rosaria Grippa ◽  
Bruno Calderoni
Keyword(s):  
Research Study ◽  
Timber Structures ◽  
Structural Elements ◽  
Bending Tests ◽  
Experimental Activity ◽  
Collapse Mechanisms ◽  
Regression Approach ◽  
Non Destructive ◽  
Non Destructive Techniques

In the context of a more wide research study for in situ mechanical identification of ancient timber structures by non-destructive techniques, the paper illustrates the experimental activity developed on structural elements made of old chestnut timber, 4x4x76 cm size: 24 squared specimens were extracted by six elements in actual dimensions, already used in a previous tests campaign. Non-destructive (ND: hygrometric, sclerometric and resistographic) and destructive (D: bending) tests were performed, the latter according to UNI EN 408 (2004) standard, in order to assess the mechanical properties and the collapse mechanisms of chestnut timber. Data gathered are presented in detail and, NDT-DT correlations, obtained through a linear regression approach, are provided to predict wood density, strength and modulus of elasticity of the tested members.

Stonemasonry skills development: two case studies of historic buildings in Scotland

2016 ◽  
Vol 34 (3) ◽  
pp. 218-241 ◽  
Author(s):  
Scott McGibbon ◽  
Mohamed Abdel-Wahab
Keyword(s):  
Case Studies ◽  
Design Methodology ◽  
Skills Development ◽  
Historic Buildings ◽  
Structural Elements ◽  
Structured Interviews ◽  
Building Stock ◽  
Content Type ◽  
Built Heritage ◽  
Industry Experience

Purpose – Scotland’s built heritage (pre-1919 building stock) is exhibiting varying levels of disrepair, in particular for stonemasonry works, despite the government’s on-going efforts for promoting higher standards of repair and maintenance (R & M) of historic buildings. The purpose of this paper is to examine the problems associated with the R & M of historic buildings. Design/methodology/approach – Two case studies (Projects A and B) exhibiting critical disrepair are reported. Site surveying was carried-out on both projects, to identify site features and R & M problems along with proposed solutions drawing on the lead author’s extensive industry experience as a stonemasonry consultant. Three semi-structured interviews were conducted with professionals involved in each project to elicit views on the challenges faced. Additionally, three industry experts were interviewed to provide a wider perspective of the R & M challenges facing historic buildings. Findings – Neglect and poor practice resulted in both projects becoming more challenging and expensive than they needed to be, which was attributed to generic and advanced skills 6deficiencies of the workforce. There is an urgent need for a multi-disciplinary approach to the development of a method statement for R & M, drawing on the expertise of professionals and contractors, particularly when specifying repairs to structural elements. Originality/value – This paper has provided original and valuable information on R & M problems, highlighting the importance of continued investment in skills development for historic building R & M to enhance existing current training provision and practice. There is a need for further similar project-based data to inform skills development strategies for the R & M of historic buildings as well as enhancing existing qualification frameworks.

The Experimental Observation of the Prestress Forces in the Structural Elements of a Tension Fabric Structure

2013 ◽  
Vol 486 ◽  
pp. 189-194 ◽  
Author(s):  
Petr Fajman ◽  
Michal Polak ◽  
Jiří Maca ◽  
Tomáš Plachy
Keyword(s):  
Experimental Observation ◽  
Measurement System ◽  
Geometrical Nonlinearity ◽  
Structural Elements ◽  
Frequency Method ◽  
Temperature Changes ◽  
Fabric Structure ◽  
Cable Forces ◽  
Non Destructive

The periodic experimental observation of the prestress forces in some selected structural elements of the tension fabric structure is mentioned in this paper. The described experiment was focused to the tension fabric roof which covers the tram stop K Barrandovu in Prague. So far the observation was performed three times and it was every time aimed on three types of basic structural elements support cables anchored to the ground, edge cables placed in a fabric pocket and fabric membranes. The used non-destructive experimental procedures are based on the geometrical nonlinearity and the frequency method, the applied measurement system was developed by authors. The dependence of cable forces on temperature changes can be found out from the obtained results.

scholarly journals Comparación entre redes de fibras sintéticas y redes de fibras de cáñamo para el refuerzo de muros de albañileria = Comparison between synthetic fiber networks and hemp fiber networks for the reinforcement of masonry walls

2016 ◽  
Vol 2 (3) ◽  
pp. 26
Author(s):  
Alessandra Vilardi
Keyword(s):  
Natural Fibers ◽  
Synthetic Fiber ◽  
Masonry Walls ◽  
Historic Buildings ◽  
Structural Elements ◽  
Hemp Fiber ◽  
Hemp Fibers ◽  
Fiber Networks ◽  
Synthetic Fibers ◽  
Bidirectional Networks

ResumenLa existencia de una gran cantidad de edificios antiguos ha movilizado la investigación para estudiar nuevos sistemas de refuerzo a aquellas construcciones que sean dañadas por decadencia fisiológica o por terremoto. El presente documento demuestra la eficacia de un sistema de refuerzo innovador para los muros de mampostería, constituyentes los elementos estructurales de los edificios históricos. Se hace una comparación entre unas redes bidireccionales de fibras sintéticas tradicionales y las de fibras naturales, ambas pegadas a las dos fachadas del muro con matriz de mortero. El resultado muestra la aplicación de las fibras de cáñamo como refuerzo sísmico y una mayor compatibilidad de estas con el material que caracterizan los edificios antiguos. AbstractThe existence of a large number of old buildings has mobilized research to study new systems of reinforcement to those buildings that are damaged by physiological decay or earthquake. This document demonstrates the effectiveness of an innovative reinforcement system for masonry walls, which are the structural elements of historic buildings. A comparison is made between bidirectional networks of traditional synthetic fibers and those of natural fibers, both glued to the two facades of the wall with mortar matrix. The result shows the application of hemp fibers as seismic reinforcement and a greater compatibility of these with the material that characterize the old buildings.

scholarly journals PERBAIKAN DAN PERKUATAN BANGUNAN SEDERHANA AKIBAT GEMPA

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Bambang Hadibroto ◽  
Sahala Ronitua
Keyword(s):  
Residential Buildings ◽  
Structural Elements ◽  
Literature Study ◽  
Repair Work ◽  
Final Project ◽  
Roof Structure ◽  
Earthquake Load ◽  
Column Joint ◽  
Materials Used ◽  
Building Engineering

Bangunan yang sering rusak apabila gempa bumi terjadi adalah bangunan sederhana atau bangunan non-engineering. Bangunan non-engineered adalah bangunan yang umumnya merupakan bangunan penduduk, rumah tinggal, dan lain-lain yang kebanyakan didirikan oleh masyarakat biasa tanpa bantuan ahli struktur. Telah banyak bangunan yang rusak akibat gempa, Sehingga  sangat dibutuhkan pengembangan metode perbaikan dan perkuatan struktur bangunan untuk memperbaiki dan memperkuat bangunan yang rusak akibat gempa. Titik-titik lemah bangunan yang merupakan titik-titik kegagalan bangunan akibat beban gempa, antara lain : join fondasi-kolom, join balok-kolom, dinding pasangan dan sistem struktur atap. Dibutuhkan perbaikan pada elemen-elemen tersebut untuk mengembalikan fungsinya seperti semula serta elemen-elemen tersebut sangat membutuhkan perkuatan sebelum terjadi gempa serta pendetailan penulangan yang akurat. Perbaikan dan perkuatan elemen struktur bangunan yang telah dikembangkan antara lain : perbaikan dinding retak dengan  metode  plesteran yang diperkuat  kawat, melapisi elemen struktur bangunan dengan lapisan beton baru, penambahan tulangan dan lapisan beton pada elemen balok, kolom dan pelat, pembuatan jangkar pada setiap 6 lapis bata dan pembuatan kolom praktis pada dinding roboh serta perbaikan dan perkuatan pada rangka atap dan plafon. Material yang digunakan dalam pelaksanaan pekerjaan perbaikan dan perkuatan bangunan sederhana akibat gempa adalah beton, baja tulangan, batu bata, bahan kimia (epoxy) untuk mempercepat proses pekerjaan serta bahan-bahan umum lainnya yang sering dijumpai dalam pelaksanaan pekerjaan kontruksi Kata Kunci : Bangunan Sederhana (Non-Engineering), Perkuatan, Perbaikan  ABSTRACT Buildings are often damaged when the earthquake occurred is a simple building or non- building engineering . Non - engineered buildings are buildings that generally are residential buildings, houses, and others are mostly established by ordinary people without the help of expert structures. Final Project is made using the method of literature study , by collecting data from a variety of books , sources and journals related to the repair and retrofitting of buildings is simple due to the earthquak . Has many buildings damaged by the earthquake , so that the much needed development of repair methods and retrofitting structures to improve and strengthen the buildings damaged by the earthquake . Weak points of the building which is the failure points of the building due to earthquake load , among others : the join - column foundation , beam - column joint , and systems partner walls roof structure. Needed improvements to these elements to restore its original function as well as those elements in desperate need before the earthquake retrofitting and reinforcement detailing accurate . Repair and strengthening of structural elements of the building that have been developed include : repair cracked wall plaster reinforced with wire method , coating the structural elements of the building with a new layer of concrete ,reinforcement and the addition of a layer of concrete on the elements of beams, columns and plates , on the manufacture of each 6 -layer anchor brick and manufacture practical columns on the walls collapsed and the repair and reinforcement on the roof frame and the ceiling. Materials used in the execution of repair work and simple retrofitting buildings caused by the earthquake is concrete , reinforcing steel , bricks , chemicals ( epoxy ) to speed up the work process as well as other common ingredients that are often encountered in the implementation of the construction works.Keywords: building a simple (non - engineering), Rretrofitting, Repair

scholarly journals STRUCTURAL ANALYSIS OF WOOD BEAMS BY NON-DESTRUCTIVE METHODS IN RESTORATION WORKS OF THE CATHEDRAL OF MORELIA, MEXICO

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 263-270
Author(s):  
M. I. Carrillo Gómez ◽  
J. R. Sotomayor Castellanos ◽  
D. Raya González
Keyword(s):  
Structural Analysis ◽  
Wave Velocity ◽  
Dynamic Modulus ◽  
Density Wave ◽  
International Council ◽  
Wood Beams ◽  
Mechanical And Physical Properties ◽  
Wooden Structures ◽  
Non Destructive ◽  
Destructive Methods

<p><strong>Abstract.</strong> In the ceiling framework of the capitular hall of the Cathedral of Morelia, the overall state of the beams of the ceiling framework of the capitular hall of the Cathedral of Morelia was diagnosed as deplorable, for which a replacement was put underway for more recently sawed beams. The focus of this investigation was to determine the humidity content of the wood, its density, the wave velocity, the dynamic modulus and the quality factor of a sample of five new beams. These parameters were compared to the medium of five old beams. For the density, wave velocity, dynamic modulus and rigidness, there were no differences found between the old and new beams. The results suggest that the mechanical and physical properties of the new wood beams are equivalent to those of the older ones. Consequently, the strategy of substituting old and deteriorated wood beams for recently sawed ones was successful and complies with the requirements of the International Council of Monuments and Sites as referred to in the principles for the preservation of historical wooden structures.</p>

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