Walls Of Nave Research Articles

Identification of Alternations in the Structure of Historical Masonry Walls Using the GPR Method Accompanied with Architectural Survey in the Former Piast Gymnasium in Brzeg

Widely used in civil engineering, GPR (ground penetrating radar) is increasingly being used to survey historic structures. However, there are still no conclusive directives on the use of GPR in the identification and diagnosis of masonry structures. The current state of the art allows only on the example of individual case studies, to draw conclusions about the effectiveness of the use of this tool. One such area, where the effective use of GPR has been experimentally confirmed, is the historic architectural survey of a heritage buildings. Due to diversity in the dielectric properties of individual construction materials, it is possible to observe on radargrams the change of electromagnetic wave patterns by materials from different phases. Traditional approach require extensive excavation efforts or core drilling, which may not always be acceptable for conservation reasons. Hence the GPR method could be interesting, non – destructive option for identification and diagnosis of historical masonry walls. The authors used the architectural survey and accompanying excavations at the former Piast Gymnasium in Brzeg to conduct a survey campaign using the GPR method. The brick walls of the building's nave have been scanned. The nave have undergone numerous alterations over hundreds of years. The GPR data has been subjected to adequate post-processing and then correlated with architectural surveys and validated on the basis of available excavations at the site. The authors highlight that GPR surveys, when combined with architectural investigations, offer a less invasive approach to examining historic structures, thereby mitigating the need for problematic excavation work.

Umetnička razmena između Bolonje, Padove, Venecije i vizantijsko-balkanskog Istoka - fragmenti ciklusa Stradanja Hristovog u crkvi u Vedrani (Bolonja)

The church of the Santa Maria Annunziata in the village of Vedrana, near Bologna, is situated along the medieval road that connects Bologna with Ferrara, Padua, and Venice. Between 2008 and 2010, fragments of frescoes, dating from the second half of the 13th century, were uncovered in the church. In these frescoes, which originally adorned the upper parts of the central nave walls until the 18th-century reconstructions, decorative elements, busts of the apostles in the scene of the Last Supper, remnants of the figures of Christ and Judas, along with several soldiers in the Betrayal of Judas scene were identified. Early researchers noted that the frescoes exhibit a stronger influence from the Veneto region, particularly the Paduan culture, rather than the influences of the art of nearby Venice. However, these frescoes also display notable influences of Byzantine art from the region of the Balkan Peninsula, received directly or through Venice.

Hypothesis on the Decrement of the First Natural Frequencies of the Santa Maria Di Collemaggio Basilica from Three Years Monitoring: The Role of the CLT Roof

ABSTRACT The long term dynamic monitoring of the Santa Maria di Collemaggio basilica revealed an unexpected trend of the first natural frequencies decreasing from their initial values estimated in 2018. The decrement of the natural frequency could originate from several factors. The structural system derives from the arrangement of four building materials: masonry (predominant), reinforced concrete (RC), timber and steel. Masonry is unlikely to suffer rapid decaying of their mechanical properties. Reinforced concrete (RC) and the embedded steel should not present decaying phenomena in the first years after built. Like- wise, the steel plates which connect the Cross-Laminated Timber (CLT) panels should not manifest a significant progression of corrosion in an indoor environment. Conversely, timber’s physical and mechanical properties, such as swelling and shrinkage, density, modulus of elasticity, strength have a time-dependent response, even in the long-term. Likely, the decaying of the natural frequencies depends on the CLT roof’s time-dependent be- haviour due to the potential modification of its mechanical properties and boundary conditions (interaction with the steel plates, e.g.). This paper presents selected results from the basilica’s three-years continuous dynamic monitoring and discusses an elementary mechanical model representative of the dynamics transverse to the nave walls. The mechanical model described by a limited set of parameters drives the assessment of the CLT roof’s possible role in causing the detected decrement of the natural frequencies.

Unloading and Reloading Process for the Earthquake Damage Repair of Ancient Masonry Columns: The Case of the Basilica di Collemaggio

ABSTRACT The repair of historical masonry columns damaged by earthquakes is a complex engineering procedure. In most cases, these elements support important vertical loads, and, for this reason, the repairing interventions (such as block replacement) could generate critical modifications of the stress pattern and eventually lead to local failures of the masonry material. In order to prevent critical situations, the repair work should account a complete unloading-reloading process of the column. However, at this time, no specific indications are provided by technical codes and guidelines. In the present paper, the unloading-reloading process developed for the stone masonry columns of the Basilica di Collemaggio in L’Aquila (Italy) is presented. Particularly, two specific unloading systems were designed and verified with advanced finite element analyses. A three-dimensional finite element model of the colonnade and supported nave wall was implemented to check if the unloading-reloading process would significantly change the state of stress in the masonry, causing local failures. The geometry of the structure was reconstructed from a complete laser scanner survey of the church, by considering all the intrinsic irregularities of heritage constructions. Finally, a comparison between the numerical results and the corresponding values measured during the worksite intervention was carried out.

A challenging archaeo-geophysical exploration through GPR and ERT surveys on the Keber Tepe, City Hill of Doliche, Commagene (Gaziantep, SE Turkey)

Doliche is an ancient city located at the northern fringe of Gaziantep in SE Turkey. The settlement spreads over a shallow hill called Keber Tepe. However, the lack of visible remains on the surface severely limits the comprehension of the spatial organization of the site. To understand the ancient city layout, but also to identify promising starting points of archaeological investigations, geophysical exploration plays a substantial role. In 2019 and 2020 campaigns, ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) surveys were conducted to determine anthropogenic structures in selected three study areas (SA) of the hill. Among them, SA-1 is adjacent to an excavation area on the south slope of the hill, where a large three-aisled Christian basilica had been discovered. SA-2 is in the eastern part of the city area, next to a sizeable civic bath building of the Roman period. Lastly, SA-3 covers the mosaic floor of the central nave and the terrace of the basilica where archaeological excavations were carried out in 2020 compaign. Archaeo-geophysical survey presented a challenging task as Keber Tepe is mainly composed of clayish-limestone and the same material had been used for architectural construction. Despite the disadvantages, GPR provided partial traces of the nave walls conforming with the existing basilica structures. The archaeological trenchs conducted in SA-3 confirm the partial reflection properties observed in the GPR sections. ERT surveys in this area provided subsurface models containing traces of anthropogenic structures unearthed. Since the findings obtained from both methods support each other very well in SA-2, we assumed that the field condition in this region of the hill is different or buried materials have lesser clay content in comparison to SA-1 and SA-3. As a result, the archaeo-geophysical survey contributed to the understanding of the archaeological structures and help to identify promising areas for further archaeological excavations.

Sensitivity analysis of geometric irregular effects on vulnerability of large-hall historic structures

The present research aims to analyse the vulnerability triggered by the irregularity in plan and elevation of the large-hall historic structures. A meaningful case San Pietro di Coppito church in L'Aquila, seriously damaged by the 2009 earthquake, is proposed as example.The presence of annexes, of transformed volumes, of incomplete structures generate asymmetries that cause eccentricities of the masses and/or of the stiffnesses that condition the global box-like behaviour and generate the response by macro-elements. The vulnerability of irregular large-hall structures increases with the ineffective horizontal stiffening.Through the visual survey of the damage and from the experimental investigations conducted at global level through the dynamic identification it was possible to highlight the effects of this irregularity on the case study hit by the earthquake. The Finite Element model has been built based on experimental data; starting from this reference model several numerical models were built and analysed, in the linear field through the modal and spectral analysis and in the non-linear field by pushover analysis, considering the geometric regularization process related to different stiffening effects of roof. Nine numerical models have been compared considering three geometric configurations - actual, irregular without bell tower and regular - combined with three constrain conditions of roof, fixed, free and partially constrained. The behaviour of the main macro-elements, façade, walls of nave, transept, choir, apse and bell tower has been considered through the sensitivity analysis of dynamic parameters; in detail, the variation of frequency values, the participation mass and displacements of related mode shapes have been evaluated for every configuration. The non-linear static analysis has been carried out to assess the structural capacity of different numerical models.

The Future of Boys

70 BRIAN MICHAEL MURPHY The Future of Boys  Where the railroad tracks run into the sea and disappear, we wonder if underwater train cars used to slam into manatees, or if the ocean crept onto land like some evolving thing testing its mutation of legs. Nothing so smooth as these rails, except the headstones adrift in the beach grass, and the brass feet of statues we tap each time we enter the falling cathedral, its roof riddled with stars. We throw rocks at the stained-glass saints and seek a feeling, like the day we realized the paintings 71 on the nave walls weren’t paintings, but mosaics, tile bits the width of locust legs, like the day we found another piano, a hobbled crow, an unspent grenade, and combined them into one song. ...

The Future of Boys

70 BRIAN MICHAEL MURPHY The Future of Boys  Where the railroad tracks run into the sea and disappear, we wonder if underwater train cars used to slam into manatees, or if the ocean crept onto land like some evolving thing testing its mutation of legs. Nothing so smooth as these rails, except the headstones adrift in the beach grass, and the brass feet of statues we tap each time we enter the falling cathedral, its roof riddled with stars. We throw rocks at the stained-glass saints and seek a feeling, like the day we realized the paintings 71 on the nave walls weren’t paintings, but mosaics, tile bits the width of locust legs, like the day we found another piano, a hobbled crow, an unspent grenade, and combined them into one song. ...

Advanced numerical insights into failure analysis and strengthening of monumental masonry churches under seismic actions

The seismic response and strengthening of two complex monumental masonry churches located in Northern Italy have been investigated through an advanced macro-modelling FE-based approach. An extensive documentary research and several field surveys have provided a fundamental preliminary knowledge of the two churches. Detailed three-dimensional FE models with a damage plasticity behavior for masonry have been developed and non-linear dynamic analyses have been performed to simulate the damage distribution in the churches and to identify the most vulnerable macro-elements. The analyses have highlighted the effects of geometrical features and masonry coverings on the seismic behavior of the two churches. The examination of the results in terms of tensile damage contour plots, maximum normalized displacements and energy density dissipated by tensile damage has provided a thorough description of the seismic response of both the whole church and the different macro-elements. In this regard, the procedure utilized could be regarded as a general guideline to follow for a realistic insight into the seismic response and failure analysis of large complex masonry structures without box behavior. From the results obtained, a hypothetical strengthening intervention has been implemented in the numerical models of the two churches according to the Italian Code, in order to quantitatively estimate the vulnerability reduction. A decrease of both tensile damage and displacements has been observed for the critical elements of the two churches in the case of strengthened models. Moreover, the results have shown the importance of the presence of the nave masonry covering to increase the effectiveness of the strengthening intervention, preventing the out-of-plane mechanism of the nave walls.

Numerical Modeling of a Church Nave Wall Subjected to Differential Settlements: Soil-Structure Interaction, Time-Dependence and Sensitivity Analysis

ABSTRACT Historic masonry structures are particularly sensitive to differential soil settlements. These settlements may be caused by deformable soil, shallow or inadequate foundation, structural additions in the building and changes in the underground water table due to the large-scale land use change in urban areas. This paper deals with the numerical modeling of a church nave wall subjected to differential settlement caused by a combination of the above factors. The building in question, the church of Saint Jacob in Leuven, has suffered extensive damage caused by centuries-long settlement. A numerical simulation campaign is carried out in order to reproduce and interpret the cracking damage observed in the building. The numerical analyses are based on material and soil property determination, the monitoring of settlement in the church over an extended period of time and soil-structure interaction. A sensitivity study is carried out, focused on the effect of material parameters on the response in terms of settlement magnitude and crack width and extent. Soil consolidation over time is considered through an analytical approach. The numerical results are compared with the in-situ observed damage and with an analytical damage prediction model.

Seasonal diversity of biodeteriogenic, pathogenic, and toxigenic constituents of airborne mycobiota in a sacral environment.

The main purpose of this study was to isolate airborne fungi and assess seasonal variations in air contamination with their particulates by determining the levels of their propagules in the nave and exonarthex of a church. We also monitored indoor microclimate as a determining factor for fungal proliferation on wall paintings, spore release, and transmission through the air. The temperature and relative humidity of the nave favoured fungal growth. A total of 33 fungi were isolated, mainly of the phylum Ascomycota, and to the lesser extent of the phyla Zygomycota and Basidiomycota. The most common were the fungi of the genera Penicillium and Aspergillus (23.55 % and 20.58 %, respectively). Sørensen's quotient of similarity (0.37) suggests moderate species overlap and constant exchange of fungal propagules between the nave and exonarthex. The autumn had the highest diversity, with 17 documented taxa, followed by the summer and the winter. The spring had only eight taxa. Quantitative analysis of the airborne mycobiota in the nave (430±84.85 to 1880±106.07 CFU m-3) and exonarthex (715±59.62 to 2295±91.92 CFU m-3) showed very high contamination throughout the year, with values exceeding the maximum permissible concentrations by most standards. Many of the fungi determined in this study are known for their biodeteriogenic, toxigenic, and allergenic properties, and are a threat not only to occasional visitors and staff, but also to valuable works of art decorating nave walls.

Characterization of Zahari Zograph’s nave wall paintings in the church “The nativity of the virgin” of Rila Monastery (Bulgaria) by vibrational spectroscopy and SEM–EDX analysis

ABSTRACTAn analytical study on the nave mural paintings of the church “The Nativity of the Virgin” of Rila monastery, Bulgaria, painted by Zahari Zograph was carried out. Vibrational spectroscopy was applied to identify the pigments and organic materials used in the mural paintings. To complement the spectral information, elemental composition of the samples was determined by SEM-EDX. The data showed that smalt with carbohydrate binder was applied for the blue background, green colour was executed by green earths and red-orange colour – by red lead. Azurite is the pigment used to paint the blue colour of the saints’ hoods. The mordant for gilding was prepared of drying oil, resin and siccative metal oxides as evidenced by SEM-EDX, ATR-FTIR and pyrolysis GC-MS analysis. The use of azurite is related to Zahari Zograph’s works as it was not found in any of the previously studied murals in the church painted by other artists.

Le pitture murali di Santa Maria Del Gradaro a Mantova

The essay discusses the painted decoration of the church of Santa Maria in Gradaro, which is here considered in relation to the constructive phases of the building it-self. The paintings in the apse and in the northern chapel, as well as the ornamental patterns on the walls of the central nave and the counter-facade, were conceived as part of the same, uniform decorative project. It involved the whole architectural container and can be dated immediately after 1295. Such date is indeed inscribed on the left jamb of the portal, and has likely been written after the completion of the church. Some frescoed fragments with figures of Saints painted in the northern chapel can instead be dated to a slightly later phase, having been done at the very beginning of the Trecento. Some fragments with a painted decoration and a velarium in the main chapel date back to an older phase, as well as the geometric decoration painted on the beginning of the right wall of the nave, at the bottom. The author thus argues that a first oratory did exist here. According to her, it was smaller and consisted of a single rectangular hall, which is now included in the apse and in the lower part of the present church.

Marine or estuarine radiocarbon reservoir corrections for mollusks? A case study from a medieval site in the south of England

Mollusk shells are frequently radiocarbon dated and provide reliable calibrated age ranges when the regional marine reservoir correction is well-established. For mollusks from an estuarine environment the reservoir correction may be significantly different than the regional marine reservoir correction due to the input of bedrock or soil derived carbonates. Some mollusk species such as oysters are tolerant of a significant range of salinities which makes it difficult to determine which reservoir correction is appropriate. A case study is presented of an anomalous radiocarbon age for an oyster shell paint dish found in the fabric of the ruined nave walls of St Mary's Church, Shoreham-by-Sea, West Sussex, England. Stable isotopes (δ18O and δ13C) were used to establish the type of environment in which the oyster had lived. Paired marine and terrestrial samples from a nearby medieval site were radiocarbon dated to provide an appropriate reservoir correction.

Seismic Behavior of a Complex Historical Church in L'Aquila

The church of S. Pietro di Coppito in L'Aquila is a case study of complexity under the structural point of view; the damage due to earthquake in 2009 is thus not easy to be interpreted. After a general overview of the damage, in situ test results are presented with a modal analysis, and finally the seismic response of the church is analyzed via subdivision into macro-elements with mutually independent structural responses. Particularly, the facade has moved out-of-plane, leading to the partial collapse of one of its upper edges and to the detachment from the nave walls. These two collapse mechanisms were studied by means of both linear and non-linear kinematics analyses, and a dynamic non-linear rigid body analysis was also performed. The triumphal arch, in contrast, was displaced mainly within its plane and was also studied by linear and non-linear kinematics limit analysis. The results thereby obtained were then compared with the outcomes of a series of finite-element non-linear incremental (push-over) analyses. On the basis of the analytical results and level of structural knowledge, this work is able to interpret the actual collapse process clarifying the global and local mechanisms and determining, then, the limits of each analytical tool.

SHM of Historic Damaged Churches

The paper shows the results of monitoring activities to check the structural response and the level of damage of two historic monument of LAquila: San Pietro di Coppito and Santa Maria Paganica, that were damaged by the main earthquake of April 2009. The diagnostics operation was planned and carried out in situ and in laboratory to verify the integrity of the residual stiffness of the structures and to define the mechanical parameters of the material. The mechanical characterization of materials was carried out through destructive tests on samples, taken directly on site, and micro-destructive tests through single and double flat jacks. To give a first qualitative assessment of overall was used sonic test (non-destructive test) on the main macro-structure. The global structural health monitoring (SHM) was carried out through ambient vibrations to define the real dynamic behavior in serviceability state and to calculate - via a modal identification of output-only systems-the dynamic parameters (mode of vibration, frequencies, displacements and damping ratios). The aim of this research is to prove the reliability of different diagnostic methodologies, the real extent of global and local damage and the extent of the residual stiffness of the macro elements of the structures (façade, tower, walls of nave, transept) that are subjected to different mechanism of failure.

St Peter at Novo Mesto Zelinsko: New Iconography for Claiming Political Continuity

This paper analyses the course of changes that followed the arival of new beneficiaries in a church of St Peter. At first it was a part of a Templar estate on the Lands of St Martin. With the abolition of the Templar order most of the Templars joined the Hospitallers. Upon the latters’ takeover of the church, the existing architecture was used as a medium for the expression of the new owner’s ideas mostly through the legend of St Ladislaus represented on the north nave wall. The architecture and architectural sculpture were retained as a framework for the display of the ideas of the new owners closely cooperating with the new rulers of the country and their interests. The church, built with one purpose in mind, was reused for a new cycle of ideological and artistic display – from the Romanesque to the Gothic, from the plain (or plain decorative) to figurative representation, from the Templars to the Hospitallers, from the Arpadian to the Angevins.

Estudio histórico-estratigráfico de los muros de la nave central de la catedral de Teruel y su encuentro con la techumbre

Dated to late 12th and early 13th centuries, the Cathedral of Teruel is a complex building whose greatest treasure is the Mudejar roof that covers the central space, declared World Heritage by UNESCO in 1986. There are some basic unknown facts about this roof, such as who built it, how, when or what it represents. There are many theories that attempt to clarify these uncertainties, but there is not much historical documentation available. During the years 2008 and 2009, a restoration of the church was conducted and part of the roof and walls remained uncovered for a short period of time. Using that temporal and unique chance, a wide stratigraphical and building analysis of the central nave walls and their joints with the roof was carried out. Thanks to this work, some important results have been discovered concerning the modifications suffered by the building. At the same time, other evidences help to further going within the knowledge of the form of the church at its earliest stages.

Vibration characteristics of vaulted masonry monuments undergoing differential support settlement

This paper assesses the feasibility of vibration testing to detect structural damage caused by the settlement of buttresses in the Beverley Minster, a Gothic church located in the UK. Over the past eight centuries, the accumulated support settlements of the buttresses of Beverley Minster have pulled the main nave walls outward, causing severe separation along the edges of the masonry vaults. Bays closer to the main crossing tower have remained intact; however, at the west end of the Minster, the crack width between the walls and vaults has reached about 150 mm, leading to approximately 200 mm of sag at the crown of the vaults. Due to uneven settlement of buttresses along the nave of the church, the Minster now has ten nominally identical vaults at different damage states. In this work, two of these vaults representing the two extremes, the most damaged and undamaged structural states, are subjected to vibration testing with impact hammer excitation. From these vibration measurements, damage indicators are extracted in the modal, frequency, and time domains. In the modal domain, the differences between modal parameters are observed to be comparable to measurement uncertainty and hence insufficient to reach conclusions about the presence of vault damage. However, the amplitudes of frequency response functions in the frequency domain are observed to indicate a clear difference between the damaged and undamaged states of the structure. A time domain autoregressive model, support vector machine regression, is also found to be successful at indicating the differences between the two structural states of the vaults. We conclude that vibration measurements offer a practical solution to detect wall–vault separation in historic masonry monuments, provided that multiple damage indicators are evaluated.

A Saxo-Norman Oyster Colour-Dish from St Mary's Church, New Shoreham, Sussex

This short paper reports the recent discovery of an oyster shell containing paint, within the fabric of the ruined north aisle wall of the Norman nave of St Mary's church, New Shoreham. Microscopic paint analysis has identified the pigment as pure yellow ochre, and subsequent radiocarbon dating has shown the shell itself to be mid- to late Saxon in origin. The shell represents a medieval colour-dish, used as such by a 12th-century artist at the church, prior to the reuse of the dish as mortared rubble in the nave wall. On current evidence, this colour-dish represents the oldest dated example, and the oldest dish found in physical association with a building, from medieval Britain.