bluuebunny/crossref_metadata_2025 huggingface dataset:
Tube-Jack Testing for Irregular Masonry Walls: First Studies
Authors: Ramos Luís F. , Sharafi Ziba
Published: October 2010

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.
Historic Buildings: Long Term Stability Evaluation Using Wireless Sensor Networks
Authors: Wu Hua Yong , Zonta Daniele , Pozzi Matteo , Zanon Paolo , Corrà Michele
Published: October 2010

An automatic diagnostic monitoring system can guarantee the safety and integrity of a historic building. In this paper, we describe the long term application of a wireless sensor network (WSN) for permanent health monitoring in the Torre Aquila, a historic tower in Trento, Italy. The system consists of accelerometers, thermometers and fiber optic sensors (FOS) with customized wireless modules and dedicated software designed for wireless communication. The whole system was completed and started operation in September 2008, and data from the various sensor nodes are collected continuously, save during periods of system maintenance and update. Based on the first 1.5 years of operation in assessing the stability of the tower, the WSN is seen to be an effective tool. Modal analysis indicates that the tower has two independent structural parts. A comparison between the acquired long term deformation measurements and simulated numerical results shows good agreement. Monitoring of ambient vibration suggests that such vibration is not now a source of concern for the stability of the tower.
Competition between Hydration and Carbonation in Hydraulic Lime and Lime-Pozzolana Mortars
Authors: Cizer Özlem , Van Balen Koen , Van Gemert Dionys
Published: October 2010

A combined reaction of hydration and carbonation takes place in hydraulic lime and lime-pozzolana mortars. Hydration reactions are the first reaction and carbonation of lime is the complementary reaction in the strength gain. Competition between these two reactions can occur in lime-pozzolana mortars if the pozzolanic material has low reactivity with lime, leading to the consumption of lime by carbonation reaction. The degree and the order of these reactions are strongly influenced by the moisture content. Hydration reactions are enhanced under moist conditions while carbonation is delayed. Curing under dry conditions does not sufficiently increase their strength because the hydration reactions are slowed down or even terminated by the full carbonation of lime in lime-pozzolana mortars. The consequence of this on the mechanical properties of the mortars is remarkable while the same impact is not observed in their porosity. Such mortars require moist conditions to ensure sufficient strength development.
Historical Analysis and Structural Monitoring Cases – Studies for an Integrated Approach
Authors: Balboni Laura , Corradini Paolo , Del Curto Davide , Valisi Luca
Published: October 2010

The paper focuses on the structural analysis of monumental buildings, particularly upon the relationship between both instrumental measurements and the preliminary studies and the general comprehension of the construction history of each single building, including e.g. the historical evolution, materials, decay.
A couple of case – study in the north of Italy are presented: the Trostburg Castle in South Tyrol and the S. Agata Church in Brescia. In these cases, cracks have been controlled by a long - time monitoring to investigate if structural damages could be influenced by the construction of underground galleries just near their foundations.
The study focuses on the structural analysis of monumental buildings, particularly upon the relationship between both instrumental measurements and the preliminary studies and the general comprehension of the construction history of each single building, including e.g. the historical evolution, materials, decay.
Collected data are discussed in comparison with the different approaches related to the knowledge of buildings, in order to evaluate limits and possibilities of proposed methods. Results underline how a deep investigation of an ancient and complex building, usually made up by a long time process of transformations and stratifications, allows to better understand the general structural behaviour.
The strong comprehension of the constructive history of each single structure and a carefully discussed cracks board can provide a wider support to plan and make the diagnostic and structural investigation, e.g. this method helps in the choice of the type of tests and instrumentation to be employed and helps to localise where measurements should be taken, empowering the effectiveness of the results. Moreover, it allows to control and to understand results.
Real-Time Diagnosis of Historical Artworks by Laser-Induced Fluorescence
Authors: Fiorani Luca , Caneve Luisa , Colao Francesco , Fantoni Roberta , Ortiz Pilar , Gómez María Auxiliadora , Vázquez María Auxiliadora
Published: October 2010

Laser-induced fluorescence (LIF) is a powerful remote analysis tool that has been successfully applied to the real-time diagnosis of historical artworks, allowing the observation of features invisible to the naked eye, as pigment composition, biological attack and restoration technique. This paper presents a LIF-based optical radar and reports on the results of its deployment during a field campaign conducted in February 2010 in Seville, Spain.
Commercial Ready-Mixed Mortars for the Conservation of Cultural Heritage: Characterization and Preliminary Durability Test
Authors: Gulotta Davide , Toniolo Lucia , Tedeschi Cristina , Binda Luigia
Published: October 2010

Historic masonries of the cultural heritage are aged and heterogeneous systems which are subjected to long-term exposition to the external environment. In such conditions, they can easily come in to contact with a consistent range of damaging agents, including water and salts sources. The related salt-induced damage is widely considered as one of the most dangerous decay process for their preservation. Conservative operations become therefore necessary and are performed with new materials that must fulfil specific requirements regarding their compatibility with the original ones and their resistance to damaging agents, especially in term of salt-resistance. The use of ready-mixed mortars in the restoration field has become a common practice and the number of commercial products currently available in the market is increasing. The present work reports the investigation on four types of ready-mixed mortars based on NHL binders and on two commercial NHL binders, together with the preliminary laboratory tests to assess the durability of mortar specimens to salt decay. The investigation provided useful information on the relationship between compositional and microstructural features and damage.
Wrocław University’s Leopoldinum Auditorium – Tests of Its Ceiling and a Conservation and Strengthening Concept
Authors: Jasieńko Jerzy , Nowak Tomasz , Bednarz Łukasz
Published: October 2010

This paper presents investigations of the wooden ceiling in the Leopoldinum Auditorium at Wrocław University (Poland). The investigations included: material, moisture content, mycological, resistographic, thermographic and dynamic load tests. The causes of damage to the valuable poly-chrome have been identified. A concept of conserving and strengthening the ceiling and the false vault is proposed.
Recent Results on Masonry Infill Walls
Authors: Willam K.J. , Citto C. , Shing P.B.
Published: October 2010

The paper summarizes the main research findings on masonry infill walls which were obtained within the framework of a comprehensive NSF-NEESR-SG project directed by Prof. Benson Shing at UC San Diego (Shing et al. 2009). The main focus of this contribution are experimental and computational observations on 2/3 scale unreinforced masonry panels bounded by a reinforced concrete frame which were subjected to cyclic push-over testing at CU Boulder under constant vertical pre-loading. This study included two-wythe masonry panels of 133in x75.5in size (3.378 x1.897m) with and without openings in form of eccentric windows and doors. The background experiments did include a suite of masonry prism tests on rectilinear and slanted masonry prisms providing important insight into the composite behavior of mortar and brick construction. The paper concludes with remarks on the experimental observations when the panels were integrated into infill walls of two-bay width and three-story height with and without retrofits of reinforced ECC layers (engineered cementitious composites) which were attached to one side for quasistatic testing at CU Boulder, and to both sides of the wall for dynamic shake table testing at UC San Diego.
RILEM Technical Committee on In Situ Assessment of Structural Timber
Authors: Kasal Bohumil , Tannert Thomas
Published: October 2010

Timber is an intriguing structural material and the only one that is truly renewable. Being biodegradable, hygroscopic and non-isotropic, it presents special challenges when assessing its integrity in structures. The presented paper outlines the major issues related to in-situ evaluation of structural timber and summarizes the work of the RILEM Technical Committee 215-AST “In-situ assessment of structural timber”. The committee was established in 2005 to bring together leading scientists and practitioners in the field of evaluation of timber in existing structures. Timber structures have been investigated for decades using numerous techniques that have been either developed specifically for the material or were transferred from other fields of investigation. A state-of-the-art report describing existing and emerging technologies and methods was prepared by the RILEM committee. The report describes the principles, the applications and the limitations of major evaluation techniques for in-situ assessment of timber. A brief discussion of codes standards and future research needs shows that much needs to be done in this area. As a present activity, harmonized test procedure recommendations are being prepared that will provide the engineering community with valuable guidance when evaluating timber structures.
Dynamic Identification and Monitoring of St. Torcato Church
Authors: Ramos Luís F. , Alaboz Murat , Aguilar Rafael
Published: October 2010

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 monitoring
Analysing Buildings from Context to Detail in Time: The ABCD Research Method Case Study: Friesland Provincial Library in Leeuwarden
Authors: Zijlstra Hielkje
Published: October 2010

Progress does not amount to destroying the future, but to preserving its essence, to generate the impetus to do it better today (Y. Ortega Y Gasset 1951). Working in the areas of history and construction technology, the spirit of these statement guided my research: developing a research method for buildings not listed (yet) as monuments but needed to be analysed before the next approach. When studying buildings it is essential to consider not only the art history, social and urban planning factors, but especially the construction engineering aspects. In this way, a deeper understanding of the underlying design and building methods used in our built environment can be developed. There have been many historical and architectural studies of buildings. The period since the Second World War has received particular interest. Unfortunately, most of these studies do not address the technical aspects of the construction of these buildings. However, these issues were covered by publications at the time these buildings were constructed. Technology provided me with the inspiration to develop a more comprehensive research method to assess buildings: Analysing Buildings from Context to Detail in time: ABCD research method. Technology, at academic level, should be considered in the analysis of a building. Here we are concerned with construction engineering, the study of the requirements associated with constructing buildings. The Analysing Building Construction in time research matrix (ABC matrix) can be used in practice. It incorporates the study outcomes which relate to the building itself. Contextual aspects as well as building aspects are included. They can be analysed at the three time levels to draw conclusions which are relevant to the future existence of the building. The case study of the Friesland Provincial Library in Leeuwarden will be worked out in the conference paper.
Numerical Analysis of Tunnelling Effects on Masonry Buildings: The Influence of Tunnel Location on Damage Assessment
Authors: Giardina Giorgia , Hendriks Max A.N. , Rots Jan G.
Published: October 2010

The architectural heritage is subjected to various risk factors like the lack of maintenance, the material decay and the external solicitations. Nowadays, due to the ever-increasing demand for urban space, a relevant cause of structural damage that the historical buildings experience is the ground settlement due to excavation works. In the city of Amsterdam, for example, the construction of the new North-South metro line will involve an area characterized by the presence of many ancient masonry buildings. A fundamental phase of the design of this kind of projects is the assessment of the risk of subsidence which can affect the existing structures. The actual method to perform this assessment provides for a preliminary screening of the buildings located in the area surrounding the excavation, in order to evaluate which structures are at risk of settlement induced damage. It is based on the simplification of the building as a linear elastic beam and the assumption of the absence of interaction between the soil and the structure. An improved classification system should take into account the main parameters which influence the structural response, like the nonlinear behaviour of the building and the role played by the foundation in the soil-structure interaction. In this paper, the effect on the damage mechanism of the excavation advance and the location of the tunnel with respect to the building is evaluated. Numerical analyses are performed in order to understand the effect of different settlement profiles of the ground. A coupled model of the structure and the soil is evaluated, taking into account a damage model for the masonry building and the nonlinear behaviour of the soil-structure interaction. This paper demonstrates the importance of 3D modelling; neglecting the tunnel advance can lead to an underestimation of the damage.
Numerical Assessment of the Ebe Schooner-Brig
Authors: Invernizzi Stefano , Bertolini-Cestari Clara , Chiabrera Emanuele
Published: October 2010

The Ebe schooner-brig was built in 1921 and sailed the Mediterranean’s sea for almost forty years, before being dissected into ninety parts to be transported in Milan (Italy). There, the schooner was reassembled and the naval pavilion of the National Museum of Science and Technology was built up all around the ship. After forty years in the museum, the ship presents significant deformations of both the deck and the keel, particularly in correspondence of the external supports. Despite several interventions in the past and a recent restoration, the deformation phenomenon is still worrying, and the understanding of the real cause is lacking from many aspects. Experts have already advanced some hypotheses, often in opposition to one another, and unfortunately, a continuous monitoring of the ship deformation has not been started yet. In the present paper, the schooner structure is modeled with the commercial finite element code Diana, considering a two-dimensional model of the ship cross-section. The obtained results allow for a deeper understanding of the stress-strain field in the schooner, providing a first safety assessment and useful hints for the design of the monitoring and future interventions.
Cultural Heritage Buildings and the Abruzzo Earthquake: Performance and Post-Earthquake Actions
Authors: Modena Claudio , Da Porto Francesca , Filippo Casarin , Munari Marco , Simonato Elena
Published: October 2010

The architectural heritage was seriously hit by the earthquake that occurred on April 6th 2009 in the Abruzzo region, especially considering the effects on a city with the size and with historical and strategic importance as a capital of a region, L’Aquila. The activities to protect that heritage have been centralized in the structure “Protection of Cultural Heritage” at Di.Coma.C. (Command and Control Quarter), managed by the Civil Protection Department. This allowed the cooperation among different involved subjects (Ministry of Cultural Heritage officers, experts on structural engineering from Universities and Fire Brigade teams), with their own specific knowledge. Keystone of the operating process was the standardization of the damage survey and of its immediate and correct interpretation, through dedicated survey forms for churches and palaces. The experience in the field of temporary safety measures was extremely interesting: ideas for engineering the process were developed, in cooperation with the work of the fire brigade men, that are highly experienced technicians in the “emergency” field. Finally, monitoring plans for some important monuments have been set up for the control of the damage progression and the analysis of the structural behavior of buildings after the earthquake and the execution of temporary interventions: two cases (St. Mark Church and the Spanish Fortress) are discussed.
Experimental and Numerical Analysis of a Two-Span Model Masonry Arch Bridge Subjected to Pier Scour
Authors: Carpinteri Alberto , de Stefano Alessandro , Invernizzi Stefano , Ruocci Gianluca , Lacidogna Giuseppe , Manuello Amedeo , Ceravolo Rosario , Degiovanni Luisa , Quattrone Antonino
Published: October 2010

A scaled model of a two-span masonry arch bridge has been built in order to investigate the effect of the central pile settlement due to riverbank erosion. The bridge model has been equipped with different Non Destructive Testing (NDT) instruments and subjected to incremental settlement of the pier. The evolution of the pier scour has been investigated experimentally by means of a hydraulic model and reproduced accordingly. The numerical interpretation of damage, carried out by finite element analyses, has been compared with the results of the Acoustic Emissions (AE) monitoring. Several ultrasonic emissions have been detected and main damage source areas have been localized.
Experimental and Numerical Analysis of Behaviour of Old Brick Masonries
Authors: Domede Nathalie , Sellier Alain
Published: October 2010

The calculation of old existing masonry structures needs a homogeneous mechanical behaviour law under tensile and compressive load until collapse. The samples extracted from existing buildings are necessarily limited in dimension and number and it is not possible to perform tests directly on a representative volume, so the numerical modelling of masonry mechanical behaviour has to be predicted from the behaviour of its constitutive elements. The aim of the study presented here was to develop a method able to define the homogeneous representative law for brick masonry from those of its components, bricks and mortar, in tension and in compression, including linear and non-linear domains. The method is numeric, fitted on experimental results. Tests were carried out on mortar samples, brick samples, and multilayer samples. Their experimental behaviour is described and a damage model is used to describe the behaviour of the masonry. An explanation is given of how the homogeneous characteristics of the masonry were defined and the influence of some parameters is presented.
Conservation of Heritage Structures in Turkey: Practice and Difficulties
Authors: Turer Ahmet
Published: October 2010

Conservation studies in developing countries might have additional problems to those that are being experienced by leading developed countries. The problems and difficulties mentioned here do not reflect the common practice in Turkey and mostly list rare cases for information purposes. Countries located in Asia and Middle East have rich structural heritage, in number and significance, which are sometimes even a few millenniums old. On the other hand, often times financial or bureaucratic constraints make the conservation studies more difficult, while technical problems remain to be an issue. It is quite interesting that sometimes having available financial support for conservation studies turns out to be the main source of problem, since quick and not well thought interventions end up damaging hundreds of years old surviving structures, rather than conserving them. Other most common application problems include use of Portland cement in humid environments causing salt contamination (which is now widely being avoided), infilling and freezing cracks that used to work as seasonal water table movement based motion or thermal expansion joints that are cyclic in nature, covering the structure to protect but forming unintentional green house effect – micro climates forming fungus, improper drainage to cause support settlements, removing earth fill or structural members to cause structural movements and cracks, strengthening parts of a flexible structure only to make it more rigid and cause to attract more earthquake forces, disable its energy dissipating mechanisms, applying improper chemicals, using incompatible material or irreversible techniques etc. are just a few to mention. The problem solution strategies in conservation studies should include internationally accepted conservation rules. Multi disciplinary teams are always recommended since combination of various expertise areas are mutually needed in conservation studies; architects, geotechnical and structural engineers, geology and material science specialists, archeologists, art historians are among the most important team members. Analytical modeling and simulations, on-field non destructive testing, instrumented monitoring (SHM), and small scale field treatment tests are recommended to be merged and used in conservation studies, because conventional methods or commercial repair/treatment materials available over-the-counter may not always suitable for a given specific case. Reversibility, minimum intervention, and respect to authenticity should be among the main principles to avoid serious conservation problems.
Masonry Walls as Orthotropic No Tension Structures
Authors: Basili Michela , Sinopoli Anna
Published: October 2010

In this paper, following the research line proposed by Milankovicth (1910) and Signorini (1925), a semi-analytical approach for the analysis of masonry walls - treated as horizontally multi-layered strata of no-tension material - is proposed in order to evaluate the stress distribution generated by applied loads. The main applications concern walls subjected only to vertical loads. The goal is to identify in the masonry wall the actual bearing sub-structures by defining at each vertical and horizontal level the transversal sections generated by the unilateral behaviour. The method proposed will allow identifying the partition of the wall into macro-elements, which depend on the centre of applied loads, and wall and bricks geometrical features. The technique adopted to approach the problem can be referred to as the search for the best shape. Two cases are discussed: corbelled masonry walls surrounding windows and arch behaviour of masonry over the window.
Pathology of the Katholikon of Hosios Loukas Monastery and Preliminary Structural Analysis
Authors: Miltiadou-Fezans A. , Vintzileou E. , Delinikolas N.
Published: October 2010

This paper summarizes the work carried out in the Katholikon of Hosios Loukas Monastery with the aim to study the pathology of the monument. The load bearing structure of the church is briefly presented along with its historical pathology and damages observed after the 1981 earthquake of Boeotia and slightly deteriorated since then. Finally, the results of a preliminary analytical study performed with the purpose to interpret the observed pathology are also presented.
The Stability of the Basilica of Maxentius in Rome
Authors: Albuerne Alejandra
Published: October 2010

The Basilica of Maxentius in Rome features the largest opus caementicium vaults known to have been constructed in the Roman Empire. The present paper presents a structural reconstruction of the building and initial stability analysis of its original geometry. The barrel vaults and groin vaults are analysed, together with the stability of the supporting and buttressing elements. This initial study yields that the original construction was stable. However, two of the three naves of the Basilica have collapsed and further study will be necessary for determining the causes of such structural failure.
Long-Term Reliability of Historical Monuments Built with Low Quality Sandstone
Authors: Verstrynge Els , Schueremans Luc , Van Gemert Dionys , Bourel Evert
Published: October 2010

The presented research concerns the long-term stability of a series of historical monuments, which were constructed with low-strength, ferrous sandstone. The main issues are the overall low compressive strength of the sandstone, the large scatter on these strength values, the sensitivity of its characteristics to water absorption and the lack of new original sandstone to replace the damaged zones. The sandstone reacts poorly under sustained high load levels, a situation which typically occurs at the base of bell towers and medieval city towers, as the dead load is considerably high compared to the compressive strength of the sandstone material. To assess the long-term behaviour of the sandstone, a test program has been set up to obtain information on its strength characteristics under monotonic and sustained loading. Therefore, test specimens were taken from the original material of a collapsed church tower. The results of these laboratory tests were used to adapt the parameters of an existing creep model to simulate the long-term behaviour of the sandstone under specific stress levels. Additionally, a number of strengthening solutions are discussed.
Safety Evaluation of Timber Structures through Probabilistic Analysis
Authors: Sousa Hélder S. , Lourenço Paulo B. , Neves Luís C.
Published: October 2010

This work presents a procedure for the use of probabilistic modelling techniques in the assessment of safety parameters of existing timber structures, when influenced by two types of actions. The parameters of the models have been defined as probabilistic variables, and Monte Carlo simulation technique was taken into account for safety evaluation. The case study here examined concerns four king post trusses on which a safety evaluation method was conducted to determine a target reliability index. Since the structures presented a high level of deterioration, a model considering the variation of the residual cross-section and the influence of environment in resistance was taken into account. Time dependent deterioration models have also been considered. With the results given by the different used models, it was possible to obtain probabilities of failure and respective reliability indices, as well as time evolution deterioration curves for a deteriorated historical structure.
Analysis and Demolition of Some Vaults of the Church of La Peregrina in Sahagún (Spain)
Authors: Huerta Santiago , Fuentes Paula
Published: October 2010

The Franciscan church of La Peregrina in Sahagún (Spain) was founded in the 13th Century. It has undergone many transformations and additions throughout its history. The most important were carried out in the 17th Century when the church was converted to the Baroque style. The apse vaults were demolished and new timbrel vaults were built hiding the Mudéjar windows. In the nave, the transverse arches that supported the modern roof were also demolished, internal counterforts were built and new barrel timbrel vaults with lunettes, erected. Eventually, an oval dome was built on the transept. Recent restoration work will give the building a new use. The project aims to recover the Mudéjar apse with its windows providing natural light to the presbytery. This involves the demolition of the Baroque vaults above the presbytery (a barrel vault terminated with a semi-dome). The oval dome will lose some buttressing to the side of the apse and an expertise was required to assess the feasibility of the operation. In the present paper the structure of the church will be described and the analysis of the oval dome with and without the presbytery vaults will be explained.
The Role of Solid Springer in Masonry Vault
Authors: Ceradini Vittorio , Candela Michele , Fonti Roberta
Published: October 2010

During a scientific research, directed to understand the structural role of some particular masonry elements, noticeable in covering structures like vault and dome, we searched the technical rules and function of these elements. We verified that in literature there is no specific documentation about these elements and its mechanic purposes. The study was directed to recognize the most representatives architectures in different ages, and to identify the construction technique’s evolution process of this particular arc-double or thickening of arc that we arrived to identify as a necessary building component to give balance in particular structural configuration. This process put down roots from the roman ancient age, until baroque age, where the most original applications of this regulation were placed. From Pantheon to the limit case of St. Filippo Neri chapel, the covers’ structures springer angle studied was analyzed together with its relation to plan, sections and elevation of all buildings. Therefore, if these elements are well-performed, they follow precise constructive patterns that this article would like to identify and show.
Analytical and Numerical Approach to the Romanian Medieval Church Structures
Authors: Szabó Bálint , Kirizsá Imola N. , Vass László
Published: October 2010

Whenever interventions on medieval churches are necessary, they must be approached as a whole, based on a numerical analysis of the load-bearing structure, especially if exceptional actions, like seismic ones, are present. Numerical analysis results can be successfully used in the assessment of quantitative elements for timber load-bearing structures. Nonetheless, masonry load-bearing subunits are more difficult to design and assess, results of the calculations made in case of elastic behaviour of the masonry structure being valid only until the first cracks. Numerical analysis can indicate, from a qualitative viewpoint, the behaviour of load-bearing structures of church buildings.. This paper presents the modelling principles of various types of load-bearing structural units belonging to medieval churches, which are subjected to dead loads and non-gravity actions, including Lutheran Church in Bistrita, Reformed Church in Aiud, Lutheran Church in Drauseni. , drafted within the Built Heritage Conservation Research and Design Centre – Utilitas, Cluj-Napoca City. It applies to three case studies, displaying their structural behaviour and contributing to the selection of appropriate strengthening methods
Two-Step Pushover Analysis of an Ancient Masonry Oil-Mill in the Southern Italy
Authors: Cundari G.A. , Milani G. , Failla G. , Nucera F. , Santini A.
Published: October 2010

Historical masonry buildings located in the Southern Italy are usually built with irregular stones joined with mortar with poor mechanical properties. Therefore, piers and spandrels ultimate resistance is not always well predicted by simplified formulas suggested by codes of practice, which typically are tailored to regular patterns. In this framework, we present a two-step numerical model –within the equivalent frame approach assumption– for the pushover analysis of in-plane loaded historical masonry walls constituted by an irregular assemblage of stones. In Step I, ultimate bending moment-shear force strength domains of piers and spandrels are derived by means of a heterogeneous upper bound FE limit analysis and the results are stored in a database. Assessing the capacity of both piers and spandrels is crucial for correctly predicting the ultimate resistance of masonry walls acted upon by in-plane loads. Heterogeneous limit analysis is particularly suitable for computing failure loads, since it permits a distinct modeling of stones and mortar joints. Appropriate static and kinematic boundary conditions are set to account for the complex interaction of internal forces and deformed shapes of single elements. At Step II, a frame model of the masonry wall is assembled, where piers and spandrels are modeled as elastic Timoshenko beams. At each analysis step it is checked that the internal forces in each structural element are smaller than the failure loads stored in the database created at Step I. If the capacity is exceeded, suitable flexural hinges are introduced at the end of the structural elements. The resistance of the element is then set to zero when a limit chord rotation is exceeded. With the numerical tool developed, a real scale old masonry oil-mill located in the Southern Italy is analyzed in the inelastic range under increasing static loads.
Modeling the Static Behaviour of a Double Curvature Brickwork Vault
Authors: Anzani Anna , Condoleo Paola , Gobbo Antonia , Taliercio Alberto
Published: October 2010

For safety assessment, a double curvature hollow bricks cloister vault with lunettes has been studied. Its geometry, constructive aspects, crack pattern have been surveyed and a 3D finite element analysis has been carried out, the numerical model exploiting the accurate survey of the vault geometry.
Victor Horta’s Iron Architecture: A Structural Analysis
Authors: Collette Quentin , Wouters Ine , De Bouw Michael , Lauriks Leen , Younes Abdelrahman
Published: October 2010

The internationally acknowledged Art Nouveau architect Victor Horta built remarkable artifacts of public iron architecture in Brussels. His projects display an innovative philosophy based on apparent iron frameworks used in a very efficient manner. As a supplement to the ample historical and architectural studies on Belgium’s most famous Art Nouveau architect, this paper puts Horta’s innovative structural practice of iron into the picture. To reach this goal, a structural analysis of four of Horta’s most interesting projects is carried out, going into the following topics: conceptual philosophy (structural typology), building techniques (shapes, connection details) and the coherence of the structural logic (structural usefulness).
Structural Changes Effect on Deflect of Tower St. Jiri on Prague Castle
Authors: Fajman Petr
Published: October 2010

The basilica st. Jiri on Prague Castle has two towers and three bodies. The north tower is deflected from vertical about 450mm. During the last measurement it was found, that the walls were diverted too. The reasons and beginning of fault genesis have not been known yet. It can be larger self weight of tower then weight of navy. It leads to different settlements during homogenous foundation conditions. The next reasons are not clear. I investigated: tower weakening by the door opening, influence of inside vault over middle navy, foundation conditions. The results obtained from numerical model show that every mentioned reason contributed to the deflection of the tower.
Stability Analysis on the Roof Trusses of the Broumov Group of Churches to Underline Statical Sense of Dientzenhofers
Authors: Kuklík Pavel , Duinker Peter , Hettinga Justin
Published: October 2010

The Broumov group of churches represents an integral part of Bohemian baroque architecture. The famous Dientzenhofer family of architects, that helped define the Bohemian baroque style in the early 18th century, designed the Broumov group for the governing Benedictine abbey of St. Wenceslaw in Broumov. This report summarizes a structural investigation, using FIN10 finite element software, into the stability and efficiency of the roof trusses design. The structures age and current state were taken into account in calculating both the applied loads and structural capacity by increasing loads and reducing material strength. A damage analysis, including identification of fungi species, was performed, documented and implemented in a three-dimensional model for comparison with undamaged results. Magnitude and distribution of axial and bending forces were determined using both two dimensional and three-dimensional models for several load cases. Using the comparison of 1st order and 2nd order structural analysis results and Eurocode specified criteria, critical and unnecessary members of the roof system were identified and evaluated. Classical linear elastic 2nd order theory was used based of Eulerian principles, ignoring geometrical non-linearity and non-linear material effects. The main analysis was performed on the St. Ann church in Viznov and St. Barbora church in Otovice.
Prince of Wales Fort: Structural Wall Analysis
Authors: Isfeld Andrea , Shrive Nigel
Published: October 2010

The Prince of Wales Fort, in Churchill Manitoba, was constructed in the early 18th century by the Hudson Bay Trading Company (HBC) in an effort to secure the fur trade in northern Canada. The fort is a Vauban style rubble masonry construction, and is the most northerly fortification of this kind. In the 1920’s the fort received recognition as a National Historic Site by the Historic Sites and Monuments Board of Canada, at which time monitoring and repairs began under the leadership of Parks Canada.
As a result of the fort’s northern latitude it has been subjected to extreme temperatures and freeze thaw cycles causing a gradual break down of the mortar within the escarp walls. Recently, climate change has led to an increase in the average local temperature shifting the thermal gradient within the earth rampart. During spring and summer, high volumes of ground water have drained through the walls washing out much of the degraded mortar. The result is a partially grouted rubble wall, encased with ashlar face stones. These deteriorating core conditions have caused significant lateral deflections in several areas and failure in others. The core wall material will be analyzed by modeling it as an irregular granular material. Using this approach, different levels of cohesion can be used to determine the in-situ mortar conditions and the strength of the structure.
Statistical Time Series Analysis of Crack Movements at Bayon Main Tower, Cambodia
Authors: Yamada Shunsuke , Araya Masato , Fukuda Mitsuharu , Iwasaki Yoshinori
Published: October 2010

Based on the past monitoring data of crack movements and various weather conditions by JASA (Japanese Government Team of Safeguarding Angkor), we quantitatively examine about the effects of each weather conditions to each crack movements at Bayon main tower. Then, we applied the time series analysis using a state-space representation in the examination. In the model of the state-space representation, the factors of crack movement are assumed as temperature, wind velocity and rainfall. Those quantitative examinations of crack movements will be necessary for the planning of reinforcement and restoration at Bayon main tower.
Stability Analysis of Monument: A Case Study–Safdarjung Tomb
Authors: Ahmad Adil , Moin Khalid
Published: October 2010

Present study deals with the stability analysis of an existing historical monument “Safdarjung Tomb” under Seismic Load. The tomb is situated at New Delhi, India. The building is classified as protected monument by the Archaeological Survey of India (ASI). This is a ground plus two storey masonry structure with a central dome.
The basic seismic parameters have been evaluated using Bureau of Indian Standards (BIS) Codal method. Distribution of lateral forces is carried out to individual piers and walls using Rigidity Approach.
The seismic performance of the building is studied under the gravity and earthquake loads. The building is modeled as a two-degree-of-freedom shear-beam system. The piers, which are located parallel to the direction of earthquake shaking are assumed to provide spring action. The mass of the walls and slabs are lumped at the storey levels. The lumped masses are assumed to be connected to each other through massless springs. The degree of each mass in horizontal direction is considered, neglecting the vertical translational and rotational degrees of freedom. Stiffness of the walls parallel to longitudinal and transverse directions of the building has been computed separately which was used for computation of lateral forces in each direction. The forces so evaluated are used in pier analysis to evaluate stress induced in various elements.
The majority of the structural elements were found safe and the overall structure is stable. The stresses due to shear and bending are within permissible limit
Structural Effects of Brick Arrangement and Span Length on Mid-Pointed Arches
Authors: Hejazi Mehrdad , Jafari Farshad
Published: October 2010

One of the most important, valuable and remarkable elments of Persian architecture is brick masonry arch. Structural behaviour of Persian brick masonry arches has not been studied in details. Any investigation into their characteristics can be beneficial for maintenance, retrofit, restoration and reconstruction of such arches. The effect of a brick arrangement in the fabric of arches, such as Roman and barrel arrangements, on structural behaviour of brick masonry arches has been a serious controversy among architects and structural engineers for many years. In this study, micro-modelling finite element technique has been used to analyse mid-pointed arches with two different brick arrangements, i.e. Roman and barrel arrangements, under static weight load using the finite element method. Analyses have been carried out and obtained results have been discussed to describe the effect of brick arrangement on structural behaviour of analysed arches with three different span lengths.
Flexural and Shear Strength of Granite Reinforced by Metal Rods
Authors: Hong Sung Gul , Lim Woo Young
Published: October 2010

This paper investigates feasibility of reinforcement method for fractured granite of slab type and beam members used as components of old stone masonry pagodas. Investigation of the effect of reinforcement to flexural and shear strength is performed using the concept for the high strength concrete since the mechanical properties of granite are similar to properties of high strength of concrete. In this experimental program two types of notched specimens are intended for failures with shear and flexural cracks. Intended fractured specimens are reinforced by metal rods, so called pinning method. The rods are inserted in holes and bonded with inorganic cement. The metal rods are supposed to transfer forces by tensile resistance in flexure and dowel action in shear. Increase in shear and flexural capacities and ductile behavior after sudden yielding of the metal rods are observed. The final failure cracks in reinforced specimens occurred different from interfaces along the original cracks. Locations of metal rods, their numbers, and construction of anchored rod are main variables to be examined for guidelines for reinforcement methods.
Experimental Study on the Injected Anchors Behaviour on Historical Masonry
Authors: Algeri Cristiano , Poverello Elena , Plizzari Giovanni , Giuriani Ezio
Published: October 2010

The proposed paper reports the results of a research on the behaviour of injected anchors in historical masonry. The purpose of this investigation was to develop a methodology to be used as a preliminary design stage for structural interventions in order to pre-qualify the real strength of this kind of anchors. Several preliminary tests in laboratory with test specimens made of concrete and masonry and a first series of in situ tests on different types of masonry were conducted to analyse the behaviour of the anchorage and of the mortar. As this test is not included in National Standard, the studied standardised methodology could be adopted as a Guideline.
Kinematic Stability of Masonry Arches
Authors: Smars Pierre
Published: October 2010

To quantify the safety of masonry arches and vaults using limit-analysis, various types of safety factors have been devised. The most well-known were introduced by Heyman: a “static factor of safety” (or load factor) assessing how vulnerable the structure is to increases in the living loads and a “geometrical factor of safety” assessing how critical the thickness of the structure is for its stability. In non seismic areas, one of the main risks of total or partial collapse of arches and vaults is excessive displacement of the supports (following walls or soil deformation). Limit analysis technique can be used to analyse this risk, quantifying movements permitted before collapse and evolution of the thrust on the supports. This analysis can be combined with pathological investigations and displacement monitoring to study the evolution of the risk and define a “kinematic factor of safety”. A software program was developed (a) to compute domains of stability for particular mechanisms of deformation, (b) to study possibility of transitions between mechanisms during deformation and (c) to interactively study the influence of movements of the supports on thrust and stability. Scaled physical models are used to validate the limit analysis approach, using an experimental rig where horizontal and vertical displacements are controlled by computer. A high-speed camera is used to study transition between mechanisms. Finally it is referred to techniques integrating this kinematic approach into a more general probabilistic approach, taking into account various uncertainties in the structure (shape, thickness, loads, movements).