Masonry Structures Historic

The majority of historical and heritage structures around the world consist of unreinforced masonry
walls. A masonry structure is composed of masonry units, such as brick or marble blocks, with or without
a joint filling material, such as mortar. A masonry with a joint material is usually made of two different
materials (i.e. masonry units and mortar), representing a non-homogeneous and anisotropic structural
component. In other words, masonry is a discontinuous structural component whose deformations and
failure mechanism are governed by its blocky behavior. Some ancient masonry structures, such as ancient
columns and colonnades, are constructed without any form of joint material between the individual
blocks. Therefore, the isotropic elastic continuum-based models are not suitable for the simulation of
the real nonlinear behavior of masonry walls under applied load.

This paper presents a methodology aimed at addressing the rapid post-earthquake damage localization and quantification tasks in heritage masonry structures, based on non-linear Incremental Dynamic Analysis (IDA). The proposed methodology relies on pre-run multidimensional non-linear IDA simulations carried out using a numerical Finite Element model together with vibration data recorded during an earthquake. The IDA curves are built with reference to different portions of the structure, relating meaningful local damage parameters to relevant seismic intensity measures. The selection of appropriate intensity parameters is crucial and a study on this aspect is carried out. The methodology is validated through application to a numerical model of a reduced-scale masonry structure, called Brick House, which is a well-known international benchmark tested on the LNEC-3D shaking table. The obtained results demonstrate that, if the set of IDA curves has been previously constructed using a suitable model, the proposed methodology yields an immediate and accurate estimation of damage conditions after an earthquake is recorded.

In this paper, we revisit the limit equilibrium analysis of masonry arches. Firstly, the major contributions during the last three centuries associated with geometric and energy formulations are discussed, and subsequently, the paper explains that the problem of determining the minimum thickness of a masonry arch capable to support its own weight has multiple solutions. The infinite many neighboring solutions for the minimum thickness of a masonry arch result from the infinite many possible directions of rupturing that an arch with finite thickness may develop when becoming a mechanism. Given this infinite number of physically admissible rupturing directions, the energy approach expressed with the principle of stationary potential energy emerges as the most powerful tool to analyze masonry arches at their limit equilibrium state. The paper concludes that vertical rupturing is the most critical rupturing direction since it results to the largest value of the minimum thickness that an elliptical arch needs to support its own weight. For the common case where there is an intrados layer of voussoirs with physical joints perpendicular to the intrados, the initial rupture has to first follow the physical joint; therefore, the broken rupture pattern reported by Lamé and Clapeyron in 1823 corresponds to the larger value of the minimum allowable thickness.

In this paper, we compute the location of the imminent hinges and the minimum thickness, t, of a circular masonry arch with mid-thickness radius, R, and embracing angle, β, which can just sustain its own weight together with a given level of a horizontal ground acceleration, ε g. Motivated from the recent growing interest in identifying the limit equilibrium states of historic structures in earthquake prone areas, this paper shows that the value of the minimum horizontal acceleration that is needed to convert an arch with slenderness (t/R, β) into a four-hinge mechanism depends on the direction of the rupture at the imminent hinge locations. This result is obtained with a variational formulation and the application of the principle of stationary potential energy, and it is shown that a circular arch becomes a mechanism with vertical ruptures when subjected to a horizontal ground acceleration that is slightly lower than the horizontal acceleration needed to create a mechanism with radial ruptures. The paper explains that the multiplicity on the solution for the minimum uplift acceleration is a direct consequence of the multiple possible ways that a masonry arch with finite thickness may rupture at a given location. The paper further confirms that the results obtained with commercially available distinct element software are in very good agreement with the rigorous solution.

More than a century ago, the Serbian engineer and astronomer Milutin Milankovitch presented a remarkable formulation for the thrust-line of arches that do not sustain tension, and by taking radial cuts and a polar coordinate system, he published for the first time the correct and complete solution for the theoretical minimum thickness, t, of a monolithic semicircular arch with radius R. This paper shows that Milankovitch's solution, t/R = 0.1075, is not unique and that it depends on the stereotomy exercised. The adoption of vertical cuts which are associated with a cartesian coordinate system yields a neighboring thrust-line and a different, slightly higher value for the minimum thickness (t/R = 0.1095) than the value computed by Milankovitch. This result has been obtained in this paper with a geometric and a variational formulation. The Milankovitch minimum thrust-line derived with radial stereotomy and our minimum thrust-line derived with vertical ste-reotomy are two distinguishable, physically admissible thrust-lines which do not coincide with R. Hooke's catenary that meets the extrados of the arch at the three extreme points. Furthermore, the paper shows that the catenary (the " hanging chain ") is not a physically admissible minimum thrust-line of the semicircular arch, although it is a neighboring line to the aforementioned physically admissible thrust-lines. The minimum thickness of a semicircular arch that is needed to accommodate the catenary curve is t/R = 0.1117—a value that is even higher than the enhanced minimum thickness t/R = 0.1095 computed in this paper after adopting a cartesian coordinate system; therefore, it works toward the safety of the arch.

In this paper, we compute the minimum thickness and the location of the imminent intrados hinge of symmetric elliptical masonry arches when subjected to their weight. While this problem (Couplet's problem) was solved rigorously for semicircular arches more than a century ago, no results have been available for elliptical arches. Motivated from the recent growing interest in identifying the limit equilibrium states of historic structures, this paper first computes two neighboring physically admissible thrust-lines which can just be located in elliptical arches by adopting either a polar or a cartesian coordinate system. These two distinguishable, physically admissible thrust-lines are neighboring thrust-lines to Hooke's catenary which is not a physically admissible thrust-line as has been shown recently. Accordingly, the paper shows that the answer for the minimum thickness of symmetric elliptical masonry arches is not unique and that it depends on the coordinate system adopted and the associated stereotomy exercised. This result is confirmed by developing a variational formulation after selecting the appropriate directions of the rupture that initiates at the intrados hinge. The paper concludes that Hooke's limiting catenary, although not a physically admissible thrust-line, offers a conservative value for the minimum thickness in most practical configurations.

Structural interventions to historic stone masonry buildings require that both structural and heritage values be considered simultaneously. The absence of one of these value systems in implementation can be regarded as an unethical professional action. The research objective of this article is to prepare a guideline for ensuring ethical structural interventions to small-scale stone historic masonry buildings in the conservation areas of Northern Cyprus. The methodology covers an analysis of internationally accepted conservation documents and national laws related to the conservation of historic buildings, an analysis of building codes, especially Turkish building codes, which have been used in Northern Cyprus, and an analysis of the structural interventions introduced to a significant historic building in a semi-intact state in the walled city of Famagusta. This guideline covers issues related to whether buildings are intact or ruined, the presence of earthquake risk, the types of structural decisions in an architectural conservation project, and the values to consider during the decision making phase.

http://link.springer.com/article/10.1007/s11948-014-9622-0

Istanbul, the capital of Eastern Rome, Byzantine Empire and Ottoman Empire, has always
been an important city, decorated with emblematic buildings. The seismicity of the city and
the surrounding area, however, has been one of the most challenging points the designer of
these daring historical structures had to face. Very strong tremors, recurring in every one and
a half century in average, hit the city leaving a tragic mark in the history. The legendry dome
of Hagia Sophia, the most important structure of the city, for instance, collapsed in 1509 due
to a strong shaking. The dome of Beyazıt Mosque, commissioned by the Sultan Beyazıt,
collapsed 3 years after its completion during the 1509 Earthquake as well. Fatih Mosque,
commissioned by the conqueror of the city, Mehmet the 2nd, collapsed during the 1766
Earthquake to such an extend that the bearing system of the structure had to be redesigned
during the reconstruction works. Atik Ali Paşa Mosque in Beyazıt Square, experienced a
severe damage during the 1766 Earthquake thus the load bearing system and the dome had to
be repaired and even altered.
This chapter discusses the domed structures in Istanbul, which are reported damaged during
strong historical earthquakes. The attention is focused mostly to their domes, the most
important component of the Byzantine and the Ottoman architecture. The significant shakings,
together with their estimated epicenters and magnitudes, have been defined and the spatial distribution of the reported damages in the domed structures has been examined. It is found
that the Historical Peninsula, which is where once Constantinople was located, has several
vulnerable structures and high seismic hazard level at the same time. Certain structures have
been found to be quite vulnerable to strong shakings and received significant damages
multiple times. The chapter discusses the possible effects of the future seismic events on the
historical buildings in Istanbul, based on the recorded damages occurred during the past
seismic events.

The paper deals with selected examples of clock towers in Bosnia and Herzegovina, representing high masonry heritage buildings made of stone, and explains the approach used in their preservation and restoration. The aim of this paper is to present a specific method of conservation used on stone structures. Three clock towers from Bosnia and Herzegovina were selected as representative examples: Sarajevo Clock Tower from the 16th century is an example of well-preserved building; The Clock Tower in Gradačac, the youngest building of this type in Bosnia and Herzegovina, is in poor structural conditions and in danger of collapsing; The Clock Tower in Banja Luka, the first clock tower in Bosnia and Herzegovina, was demolished in 1993 but the reconstruction project is planned for the current year. This paper addresses the structural properties of masonry clock tower from the Ottoman period, with special attention to preservation, analysis and strengthening. These tasks are still a challenge for masonry practitioners even if significant advances in research have been made in the last decades. The dynamic behavior of the historical buildings is usually analyzed to design repair intervention solutions and retrofitting. The structural behavior is analyzed using FEM modeling to examine how far the structural defects endanger the stability of the tower. The soil properties problem under the tower has been considered. Simplified yet effective procedures have been used as well. Results of the analysis have confirmed insufficient performance of the structure under horizontal action and the need for improvement.

Nowadays, masonry heritage buildings usually experience changes during exploitation. In areas of emphasized seismic risk, in cases of extensions, alterations to the original dimensions, reconstruction (the removal of bearing elements, replacement of materials, introduction of new fittings), or the subsequent erection of properties close by, with a comparison of the foundation levels change of use, refurbishment, extension, or additional building to an existing building. It is necessary to analyze the seismic aspect of such interventions in seismic prone areas. At first, we'll focus on the legal and technical regulations. For start we'll look back at UNESCO's Program on Masonry Heritage, then domestic and regional legal and technical regulations and with all of that we will define the first step of the process. Next step would be a detailed registration of the current condition of the building, and also determining the characteristics of the embedded materials. The load bearing structures of the building must also be accurately identified, with all relevant measurements and, in particular, a description of the building materials and their condition. This includes all detailed maps, plans, and details of the used materials, and especially detailed record of all the damages on the structure. Even at this early stage of investigative works it may prove necessary to secure certain structural elements, or even the entire building, to prevent it from collapsing. As a rule, this requires not only the removal of the outer cladding or even of parts of a wall to determine the depth of cracks but also, if there is any suggestion of subsidence, excavations around the building or to the depth of the foundations. Calculations, based on the planned and current condition of the building, will show whether the strengthening and rehabilitation are needed for the structure. The elements that need reinforcement or conservation can be identified during the initial visit, and provision can immediately be made to take the necessary steps to relieve the load. It is necessary to do all the steps regarding technical regulations, legal regulations, methods of approach, theoretical consideration, methods of calculation, and in the end to determine the needs of that building. Theoretical consideration regarding the determined condition of structure, from all the above aspects, is the next step to be done. This also includes evaluation of the viability of these interventions, based on experience. The most sensitive issue, without doubt, is determining the condition of the foundations. This should be addressed with the utmost care with the general opinion of the building's stability in mind.

Caerphilly Castle (1268-70) is the first concentric castle in Britain and the second largest in the UK. The dramatic inclination of its ruinous south west tower has been noted since 1539. Comparing data from historical surveys and a terrestrial laser scan undertaken in 2015, this paper seeks to review evidence for the long-term stability of the tower. Digital documentation and archival research by architects is collated to provide data for structural analysis by engineers. A terrestrial laser scan was used to create a detailed three dimensional finite element model to enable structural analysis of the current shape of the tower made by tetrahedral elements. An automated strategy has been implemented for the transformation of the complex three dimensional point cloud into a three dimensional finite element model. Numerical analysis has been carried out aiming at understanding the main structural weaknesses of the tower in its present condition. Comparisons of four sets of data: 1539, 1830, 1870 and 2015 enabled us to determine change albeit between very different methods of measurement.

The most important issue addressing the cultural heritage safeguard has to do with our cultural identity, it is a simple statement and a fact. Stressing the relevance of its conservation, that frequently is put on the line by the recurrent earthquakes, it must be attained through the prevention engineering. On this with reference to Palazzo Murena, current headquarters of the University of Perugia and designed by the prominent Architect Luigi Vanvitelli, the results of the research activities conducted through the PRIN 2015 funding scheme, are presented. A preliminary seismic global analysis on a FME model, created using the data gained by mean of innovative survey instrumentations, has allowed to identify in advance the most vulnerable portions of this ancient masonry building and to consequently finalize (and so reduce) the successive execution of the onerous and invasive investigation methodologies (like drills, endoscopies, flat jack tests ...). Afterwards, on the basis of the increased level of knowledge deriving by the conscious use of the aforementioned experimental campaign, the numerical model has been refined in order to tune up the global seismic evaluation of the masonry building in its actual state. It revealed the good performance of the masonry structures but confirmed that some portion of the artefact deserves anyway to be improved. In response, by structural and numerical verification, a real reinforcement plan has been designed conceiving the application of natural FRCM composite material without running the risk of irreversibly undermining of the socio-architectural prestige of the building; circumstance also linked to the accessibility and to the function of such a strategic building.

En 1509, Íñigo López de Mendoza, II conde de Tendilla, explicaba que la inclusión del cimborrio en la Capilla Real de Granada era una cosa que da[ba] mucha vista y ahermosea[ba] en gran manera la Capilla y [hacía] el edificio real y magnifico. Para esas fechas tempranas del siglo XVI, el cimborrio se había convertido en un elemento dignificador de la arquitectura religiosa. Al alarde técnico que suponía su construcción, se unía su doble funcionalidad en el templo, ya que permitía aumentar la iluminación interior de los edificios –se trataba, en última instancia, de una figura de luces, tal y como lo definirá Simón García años más tarde–, que servía, a su vez, para subrayar el eje central del espacio religioso allí donde se cruzaban los brazos de la cruz. Estas razones prácticas y simbólicas favorecieron la construcción de este tipo de estructuras en toda la Europa cristiana a lo largo de la Edad Media y parte de la Moderna. El fenómeno también puede observarse en la Península Ibérica, donde comienza muy pronto, y se prolonga hasta fechas muy avanzadas. Trataremos de seguirlo a través de los ejemplos –y de los diseños– conservados.
Íñigo Lopez of Mendoza, the Second count of Tendilla, explained in1509 that the inclusion of the cimborrio in the Royal Chapel of Granada was a thing that gives many sight and embellishes in great way the Chapel and this inclusion transformed the building in to royal and magnificent. At the seearly dates of the 16th century, the cimborio had become a dignifying element of the religious architecture. The advantages were undoubted. First, the technical ostentation that supposed its construction. In addition, it had a double functionality in the temple, since it was allowing to increase the interior lighting and serves to underline the central axis of the religious space where the two parts of the cross were crossing. These practical and symbolic reasons favored the construction of this type of structures throughout the whole Christian Europe during the Middle Ages and part of the Modern one. The phenomenon can also be observed in the Iberian Peninsula; there it begins very early, and continues until very advanced dates. We’ll try to follow it through the examples –and of the designs– preserved.

This article presents the data and conclusions derived from research on Roman-period masons’ marks from Syria-Palaestina and Arabia. As one of the regions of the Roman East, Syria-Palaestina and Arabia were characterized by stone architecture of long-established tradition, but the use of masons’ marks is first attested in the architecture of Herod the Great, and continues afterwards throughout the building boom of the Pax Romana period. The marks engraved on imported architectural fragments belonged in the sphere of pan-Roman trade and marble artisanship, but the marks engraved or paint-ed on local stones related only to local quarries and construction sites. As evident from examples of well-researched sites, such as Hippos of the Decapolis, the marks were used to facilitate the assemblage of buildings (construction marks) and to ensure accurate payment for those who supplied the stone (workshop marks). The marks give evidence for the identity and work organization of the local stone-masons from one of the provinces of the vast Roman Empire during the prosperous period of the Pax Romana.

Egypt is famous for its cultural heritage and historic attractions that span thousands of years. This cultural heritage is one of the tourism industry motors which contributes significantly to the country's gross domestic product (GDP). Historic Cairo has been declared as a UNESCO World Heritage Site for having hundreds of mesmerizing historic Islamic and Coptic structures; however, tourism-revenues are quite small relative to the ones generated from the famous red sea resorts and Luxor and Aswan ancient sites. This is because most of these structures are partially or completely closed due to the need for restoration and/or their poor structural condition. However, conserving these structures is quite challenging due to its complexity, lack of funds for restoring hundreds of historic structures, and lack of structured funding system. Therefore, this paper proposes a framework for a new multi-objective optimization model that prioritizes competing historic structures for the limited funding available while maximizing the structural physical performance and the socioeconomic benefits over a specified planning horizon, considering: the expected deterioration behavior over the funding period, vulnerabilities to further damage, costs associated with the conservation method, and the structure's relative importance in terms of its value. In essence, the new model will help decision makers determine the optimum restoration plan to open the deteriorated historic structures to the public, and thus increase tourism-based revenue generating streams to rejuvenate the tourism sector in Historic Cairo, and have a positive impact on Egypt's economy.

The present paper reports an in situ experimental test campaign carried out on existing buildings, in order to investigate the seismic behaviour of traditional masonry walls subject to out-of-plane loads. For the testing proposes, an experimental test setup based on a self-equilibrated scheme was developed and optimized to be applied in situ in two specimens on original and strengthened conditions. The obtained results are presented and carefully discussed namely from the reinforcement solutions’ efficiency point-of-view, as well as compared to previous experimental data obtained for the same type of masonry walls.

Additionally, a simplified linearized displacement-based procedure was adapted in order to characterize the non-linear force-displacement relationship for unreinforced traditional masonry walls and to analytically predict the experimental test results. The confrontation between the experimental and the analytical results are presented and discussed.

ABOUT CONFERENCE AND CONFERENCE AIMS Masonry structures are the heart of civilization as we understand it - foundations, backbone, and underlying form. Historically constructed of stone, brick or other more accessible materials in their context such as mud etc. they have contributed to creating what we now might consider inspiring or ‘picturesque’ settlements around the world, whether still in use or as vocal remains from past. The builders of the time, whether local village tradesmen or master masons, transmitted their knowledge of effective ways of building in or for given contexts. These ideas and methods spread throughout their own regions, and further afield, to be adapted as required to cater for differing climatic, social, religious or political needs as suited to their time. As witness to those past needs and processes these constructs can be read and interpreted in many ways, and in current times much of this knowledge and our own culture’s fundamental relationship with those skills and earth grown materials thrives as a powerful living tradition. Over time historic buildings become exposed to widely differing challenges. Today, many old masonry structures may often be perceived as ‘decayed’ due to degradation by force of nature, force majeure or as a consequence of passing time and simple neglect. Sometimes caused by inappropriate interventions, reversible or irreversible, made without understanding of possible consequences. Additional layers of value in our perception of historic structures may come from not only the built artefacts themselves but by tracing old industrial sites of brick production or stone quarries from which stones were taken, discovering and understanding manufacturing technologies and traditional buildings techniques. In brief, decay of these structures varies hugely in its scale and nature, but often we love and value those decayed structures beyond their historic, social, political, memorial or religious importance, through innate human need and emotional appeal, maybe we ‘need’ them for our own social and mental stability in our increasingly challenging world? How though might we perceive this decay technically? As a matter of physical degradation only, as visible traces of history, or as something else. If a structure is considered to be of value then these questions open pathways to the issue of intervention – preservation, conservation, or even none? Inappropriate intervention to buildings or structures risks losing the patina that creates their charm or cause further damage. Attempting to understand all the possible values, whether historic, architectural, aesthetic, artistic or intangible while determining potential action in contemporary time, is to question our response to decay: should the actual decay become a part of the buildings‘ future – what would that mean? At the 5th International Conference "The Importance of Place-The Charm of Built Heritage Decay" 2021, we are anticipating discussions around patterns of decay, including metaphysical attributes. We are inviting distinguished guests, including professionals in the discipline of heritage engagement to share and discuss their experiences, knowledge, points of view, and potential interventions on the masonry building, the relationship between patina and new additions, opinions around preservation and conservation alongside wider attitudes towards decay, and its eternal intrinsic appeal.

The current Special Issue focuses both on recent advances in graphic statics and on the examination of the old graphical methods from a more modern viewpoint. Suitable topics include but are not limited to the following:
Applications of graphic statics to the mechanics of
historic masonry constructions;
Historical approaches using graphic statics to
design structures;
Thrust network analysis;
Extension of graphic statics to 3D structures;
Recent advances in graphic statics;
Applications of graphic statics to the mechanics of
trusses;
Applications of graphic statics to bending analysis
and design;
Applications of graphic statics to concrete
structures;
Applications of graphic statics to timber structures;
Numerical tools using graphic statics;
Analytical and computational graphic statics;
Structural optimization using graphic statics;
Design of funicular forms;
A modern interpretation of the historical method of
graphic statics.
We would be grateful to you if you could spread this
information to anyone who might be interested.
Deadline for manuscript submissions: 30 June 2021

In February 2012, a part of the medieval city wall of Visby collapsed. The wall was constructed in several stages in the 13th and 14th centuries. It was decided that the collapsed part of the wall should be rebuilt. To determine a procedure for the rebuilding and to secure a safe work site, it was necessary to define the construction and structural behaviour of the wall. Furthermore, the cause of the collapse needed to be identified, in order to assess and predict the risk of future damage to other parts of the wall. An investigation into the construction of the wall was carried out through archival research and on-site examinations. Laser scanning
made it possible to describe and study the geometry of the wall and the damage in detail, and a structural analysis was carried out. The results show that the wall was built in two stages, making its construction complicated. The structural analysis indicates that there is a concentration of forces to the outer masonry leaf of the lower part of the wall. The collapse was most likely triggered by freezing of the water contained in the masonry. The combination of high stress levels in the outer masonry leaf, due to the construction of the wall, with a loose core,
thin outer masonry leaf and insufficient binding stones and weak adhesion in the bedding lime mortar in the lower part of the wall, resulted in a domino effect that explains the extent of the collapse. To secure the wall during dismantling, a temporary steel structure was constructed.
The medieval types of construction and material in a two-leaf masonry wall have proven to be durable if correctly implemented, with sufficient binding stones and a core in order, and will therefore be used for the rebuilding.