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The majority of buildings in the world are made of masonry, and some of these buildings are historical constructions with heritage values. It is commonly known that masonry can withstand significant compressive stresses, but since it lacks tensile strength, it is more susceptible to dynamic actions. In this aspect a curvature was introduced in masonry constructions in order to reduce the tensile stresses and exploit their compressive strength. This innovative structural element in the past enabled crossing large spans without intermediate supports at the cost of a horizontal thrust transmitted to the supports. The structural condition of the supports constructed of masonry is of crucial importance to resist this horizontal force that varies in intensity based on the type of curvature of the arch. Additionally, a non-standard approach including joint friction has shown to be important in such structures and therefore sliding mechanisms are investigated. Research on critical parameters affecting the safety levels of piers under the thrust of arches is carried out using an in-house code (ALMA) that uses limit analysis as a rigid block approach to modeling masonry with frictional joints. Under two cases of vertical live load, symmetric and asymmetric, the different pier textures, levels of joint friction and arch shallowness, were examined. The main outcomes of the study demonstrate that even before initiating any expensive testing campaign, complex structural analysis, the investigation of these parameters in the structure itself present the most important features of its safety level and vulnerability., Presented at the 11th International Civil Engineering, Infrastructure and Environment Conference (IC-CEIE) 2022, Kosovo.

Among the most characteristic structures in historical constructions for crossing large spans are the masonry vaulted structures. By utilizing their ability to withstand compressive forces and giving a particular curve to compensate for their lack of tensile strength, such distances can be overcome. In the case of ancient masonry, a pier's ability to bear such stresses and safely convey them to the support is directly related to its structural health, as well as a number of other factors. Additionally, historic masonry usually has dry or weak mortar at the joints, concentrating the weaknesses at these spots. In this case, Heyman’s infinite friction hypothesis may not be accurate for the assessment of existing structures as it is not able to capture the sliding mechanism. Therefore, a rigid block model with no tension and frictional joints may be suitable to account for the discontinuous nature of the masonry and, with very few input parameters, provide reliable safety assessment in terms of collapse mechanism and multiplier, able to seize both rotational and sliding modes. Using an in-house code [4,5] that utilizes limit analysis as a rigid block approach to modelling masonry with frictional joints, a study on the crucial parameters impacting the safety level of piers under the thrust of arches is performed. The pier texture, joint friction angle, and arch shallowness, namely shallow, semi-circular, and pointed arches, were investigated under two load scenarios: horizontal and concentrated vertical live load. The main findings of this work show that all studied parameters have a significant influence on the structure response. Higher friction values, sharper arches and piers that follow the rule of art result into higher collapse multipliers., Presented at the XXV Convegno AIMETA - Palermo, Italy 4/8 September 2022.

This document presents the protocol adopted to perform a systematic review for the DTADD project following the checklist provided by PRISMA and guidelines of the PRISMA-P Explanation and Elaboration.

This document presents the search strategy adopted to perform the systematic review of the DTADD project and it is based on the PRISMA-S checklist.

A significant number of scientific research groups are still nowadays dealing with masonry material as the main focus of study since it provides an open field of research that is far from resolution in a standardized manner. As masonry structures are highly vulnerable to any level of natural hazards, especially seismic activity, both traditional and composite materials have been used as reinforcements in masonry and provide different solutions that meet the key requirements set out by cultural heritage organizations. Extensive effort has gone into developing appropriate techniques of assessment, that usually demand an individualized methodology of analysis that is to be handled through comparative studies that require results validation. A very appealing field of study is the Limit Analysis approach towards masonry structures, as it offers quite accurate and, more importantly, robust results regarding this necessity to resolve the many diversities involved in the masonry numerical representation to achieve the outcomes required for the assessment. The enrichment of a limit analysis homemade code with the inclusion of diffused cohesion and frictional behaviour at the interface level is able to account, in a simplified but very robust manner, the perplexing issues involved with the numerical assessment of reinforced masonry structures. The cohesion incorporation is calibrated for a variety of in-plane applications, accounting for the joints’ indirect tensile strength, that is able to simulate the strengthening measures. Results obtained are validated with literature and included in a comparative study between discrete numerical models that utilize different modelling strategies., Published in the proceedings of the 7th International Conference on Mechanics of Masonry Structures Strengthened With Composite Materials (MuRiCo)

This document presents the search strategy adopted to perform the systematic review of the DTADD project and it is based on the PRISMA-S checklist.

This document presents the protocol adopted to perform a systematic review for the DTADD project following the checklist provided by PRISMA and guidelines of the PRISMA-P Explanation and Elaboration.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska- Curie grant agreement No 101066739.

Cultural heritage is increasingly threatened not only by traditional causes of decay, but also by changing social, economic and environmental conditions. The deterioration or disappearance of any cultural item constitutes a harmful impoverishment of our heritage. Besides, culture has been recognized as an enabler and driver of sustainable development, peace and economic progress, which highlights the necessity of fostering its documentation, protection, and promotion. For all these reasons, working in the conservation of our cultural heritage should not only be justified but encouraged. The general objective of this PhD thesis is to contribute with the efforts to achieve Target 11.4 of the Sustainable Development Goals (SDG), adopted by the United Nations (UN) in 2015, by strengthening the efforts to protect and safeguard the world’s cultural and natural heritage. The aim of the research is to increase awareness regarding the importance of vernacular architecture and its intrinsic values, as identified on the International Council of Monuments and Sites (ICOMOS) Action Plan for the Future. It specifically focuses on the improvement of earthen architectural heritage conservation, as this group of structures is particularly vulnerable to environmental and anthropologic threats. The thesis presents a summarized and concise picture of the present situation of the remaining earthen buildings in Ireland, identifies their main characteristics, the values that make such buildings important, evaluates their vulnerability as vernacular architectural style and therefore, allows to understand and better approach any future intervention on such kinds of structures. Within the context of current conservation practice, which is based on a scientific approach and implements a cyclic method of research, diagnosis, intervention and control activities, the thesis contributes to the development of quantitative research methods. A first contribution is presented on the structural analysis of cob by evaluating the suitability of available constitutive material to model its non-linear structural behaviour using two of the most commonly used Finite Element Method (FEM) software in the market, ANSYS and ABAQUS. A second contribution is concerned with the experimental testing of cob. A Minor Destructive Test (MDT) known as the flat jack test, has been experimentally validated by testing it in a series of cob wallettes built in the laboratory of Civil, Structural and Environmental Engineering (CSEE) at Trinity College Dublin (TCD). The purpose of the experimental campaign was to assess the feasibility of the technique to measure the average compressive levels of stress in existent cob walls and estimate their mechanical properties. The principal results show that effectively the test can be applied in cob walls but it tends to overestimate the stress values by a factor of approximately two. As conclusion, it is advised to correct the average compressive stress, fm, by using a value for the dimensionless geometrical efficiency constant, Ke, of 0.51. The use of a more realistic value would prevent the design and application of over invasive interventions that may place in danger the value of the historical fabric. The double flat jack tests allowed to estimate the mechanical parameters of the material to a good degree of certainty. Finally, a parametric analysis of cob walls is presented with the aim of providing conservation practitioners with rule of thumb guidance to assess the safety of existent cob buildings under seismic actions. The methodology presented in this regard is not limited to the Irish context but could as well be implemented in different countries where the seismic hazard represents an actual threat for the structural safety of remaining vernacular cob buildings.

Reuse and Redevelopment Proposal The proposal consists in the adaptation of the Market House into a Craft Training and Sustainability Research Centre. The crafts that could be learned are: • Earthen construction techniques • Thatching • Stone and brick masonry • Traditional plastering • Others The space would host a permanent exhibition of the history and importance of Irish market houses (with a special section on the history of Newtownbutler’s Market House and Lanesborough Hotel) and a library with material specialized in craftsmanship and sustainability topics open to all public., Presented at the International Summer School: Conservation Without Frontiers, Survival and Revival organized by Ulster Architectural Heritage in partnership with Irish Georgian Society.

Cob is an earthen construction technique used to build monolithic load-bearing walls. Mainly of vernacular nature, remaining cob buildings can be found throughout Europe as well as in other specific locations around the world. The aim of this paper is to evaluate the available material models’ suitability for the modelling of cob’s structural behavior in one of the most commonly used FEM software in the market. The stress-strain graphs obtained and the failure mechanisms observed after a simple compression and diagonal compression experimental campaign in cob wallettes were replicated using three different material constitutive models, namely, MISO, CONCR, and DMGE/DMGI. Furthermore, a mesh size sensitivity analysis was performed following a mesh refinement approach. MISO could reproduce the pre-peak behavior of cob and principal stresses could be used as an indication of the opening of cracks. On the other hand, it did not capture the softening post-peak behavior of the material. CONCR provided quite accurate pre-peak behavior results and peak strength values. Moreover, it was possible to plot the opening of cracks and those plots agreed with the experimental results. Nevertheless, as CONCR is suitable to reproduce brittle failures, it did not capture the long deformations characteristic of cob. Finally, the DMGE/DMGI proved to be inaccurate to reproduce both pre-peak and post-peak behavior. Although parameters could be calibrated to obtain the appropriate peak strength, neither stresses nor did strains correspond to what was observed in the experimental campaign.

Even though Irish meteorological conditions are adverse for the development of earthen con-structions, earth has been used as a construction material in Ireland for more than 4000 years. The objective of this paper is to present a summarized and concise picture of the present situation of the remaining earthen buildings in the country, identify their main characteristics, the values that make such buildings important, evaluate their vulnerability as vernacular architectural style and therefore, understand and better approach any future intervention on such kinds of structures. In particular, the paper highlights the lack of a detailed descrip-tion of traditional construction techniques and of recommended procedures for the conservation of existing earthen structures. The paper identifies the pertinent Irish texts and suggests how recent research on the me-chanical properties of cob and state-of-the-art numerical analysis techniques and constitutive models can be used to assess the strength and stability of existing historic structures.

The structural simulation of masonry elements has been traditionally conducted with Finite Element Models (FEM). Studies from the literature show that these models are capable of accurately reproduce the structural behavior at a micro and macro-scale levels. Despite the good results obtained, the application of FEM implies simplifications regarding the failure modes and the constitutive laws used to represent the behavior of bricks and mortar, as well as the interface between them. Alternative methods are available nowadays for the same purpose. An example is the Discrete Element Model (DEM) that is based on a particle-particle interaction. The simple definition of the interactions in the DEM is an advantage for the simulation of masonry elements. The objective of this master thesis is to evaluate the applicability of DEM to simulate the structural behavior of masonry at a micro and macro-scale level, reproducing the response in terms of deflections, ultimate load and failure modes. First, a review on the literature about DEM and about its application to the analysis of masonry structures was performed. Then, experimental programs conducted by other authors were selected and taken as a reference. Next, the tests found in these experimental programs were simulated with DEM. The numerical results were compared with the experimental data in order to highlight the accuracy, advantages and drawbacks of this approach. A parametric study was as well conducted to evaluate the sensibility of the results to changes in the input parameters of the model. Finally, further research proposals are presented in order to explore in a deeper and more extended way the topics presented on this dissertation It was found that the use of DEM to simulate the structural behavior of masonry at a micro and macroscale level, reproducing the response in terms of deflections, ultimate load and failure modes presents quite good results. Good agreement was shown in the description of failure modes and low percentage errors (below 10 %) were found on the computation of the parameters of interest such as strength of the material and maximum resistant load. La simulación estructural de elementos de mampostería se ha realizado tradicionalmente con modelos de elementos finitos (FEM, por sus siglas en inglés). Los estudios de la literatura muestran que estos modelos son capaces de reproducir con precisión el comportamiento estructural a micro y macro-escala. A pesar de los buenos resultados obtenidos, la aplicación de FEM implica simplificaciones con respecto a los modos de falla y a las leyes constitutivas utilizadas para representar el comportamiento de ladrillos y mortero, así como la interfaz entre ellos. Métodos alternativos están disponibles hoy en día para el mismo propósito. Un ejemplo es el Método de los Elementos Discretos (DEM, por sus siglas en inglés) que se basa en una interacción partículapartícula. La definición simple de las interacciones en el DEM es una ventaja en la simulación de elementos de mampostería. El objetivo principal de esta tesis es evaluar la aplicabilidad de DEM para simular el comportamiento estructural de la mampostería a un nivel de micro y macro-escala, y reproducir la respuesta del material en términos de desplazamientos, carga última y modos de falla. En primer lugar, se realizó una revisión de la literatura sobre el DEM y sobre su aplicación al análisis de estructuras de mampostería. A continuación, un programa experimental llevado a cabo por otros autores fue seleccionado y tomado como referencia. Después, las pruebas de laboratorio realizadas en dicho programa experimental se simularon con DEM. Los resultados numéricos obtenidos se compararon con los datos experimentales con el fin de poner en relieve la precisión, ventajas y desventajas del enfoque DEM. Se llevó a cabo además un estudio paramétrico para evaluar la sensibilidad de los resultados a los cambios en los parámetros de entrada del modelo. Finalmente, una serie de propuestas para futuras investigaciones es presentada con el fin de explorar más a detalle y de forma extendida los temas tratados en la presente tesis. Se encontró que el uso de DEM para simular el comportamiento de la mampostería a niveles micro y macro-escala, reproduciendo la respuesta en términos de desplazamientos, carga última y modos de falla, presenta buenos resultados. Concordancia en la descripción de los modos de falla y valores bajos de errores porcentuales (debajo del 10 %) fueron encontrados en el cálculo de los parámetros de interés como lo son la resistencia de los materiales y la carga última soportada.

El análisis estructural abarca el procedimiento mediante el cual se determina la respuesta de unaestructura ante las distintas acciones externas que actúan en ella a lo largo de su vida útil. Esteprocedimiento se puede dividir en tres etapas que son: a) Modelar la estructura. b) Determinar las acciones de diseño. c) Determinar los efectos de las acciones de diseño en el modelo de estructura elegido. El propósito de este proyecto es aportar en la primera de estas etapas al presentar un modelo quese apegue más a la realidad y que por lo tanto proporcione resultados que concuerden mejor conlo que se pudiera presentar en campo en este tipo de estructuras. La importancia de esto estribaen la necesidad de representar nuestro modelo lo más realista posible ya que si no tomamos encuenta este aspecto los resultados obtenidos aún con los mejores y más avanzados métodos deanálisis no representarán de una manera adecuada el comportamiento de nuestra estructura y surespuesta ante las acciones externas actuantes en ella. No se busca modificar lo establecido en reglamentos de diseño o construcción ni tampocoestablecer nuevos parámetros de diseño. Este trabajo busca profundizar un poco más en lostemas de Análisis Estructural e ir más allá de lo visto en las clases impartidas en la licenciatura.Más específicamente, este trabajo se enfoca en el análisis de estructuras por el método matricialde las rigideces o también llamado de desplazamientos. Presentaremos la inclusión de los segmentos rígidos en los nodos y de la influencia que estospueden tener en el análisis de una estructura, sobre todo en el valor de los desplazamientoscalculados de esta. Para esto desarrollaremos este planteamiento desde tres enfoques distintos,el primero es una relación estática entre grados de libertad y elementos mecánicos que involucrael desarrollo de la matriz de flexibilidades de un elemento marco, y con la ayuda de una matrizde relación estática podremos obtener la matriz de rigideces de dicho elemento. El segundo esun planteamiento basado en condensación estática en el cual de inicio se plantea la existenciade tres elementos en lugar de solo uno, pero gracias a este proceso podremos disminuir losgrados de libertad a tratar en la solución del sistema, obteniendo una matriz de rigidez de unaespecie de macro elemento, y finalmente en un capítulo subsecuente desarrollaremos unplanteamiento basado en transformaciones cinemáticas. Dada la dependencia directa que sepresenta en los grados de libertad en el extremo con respecto a los que están en el límite delsegmento rígido, se generará una matriz extra de transformación que modificará la matriz derigideces del elemento incluyendo así la influencia de los segmentos rígidos en el análisis de laestructura. Inicialmente presentamos un capitulo referente a los antecedentes de esta área de estudio dentrodel cual tratamos de manera somera los hechos más importantes que han contribuido en eldesarrollo y en la gran importancia que tiene actualmente el análisis estructural matricial. Después ahondamos un poco en los conceptos básicos que nos ayudan a comprender y manejaresta poderosa herramienta. Concluiremos este capítulo con un resumen del procedimiento quese debe de seguir para aplicar el método matricial para la obtención de los desplazamientos enuna estructura. A continuación presentamos el tema de los segmentos rígidos en los elementos y su influenciaen el comportamiento de una estructura lo cual es el punto principal de este trabajo de tesis.Igualmente desarrollamos el primero de los enfoques mencionados y en dos capítulossubsiguientes cubrimos los otros dos enfoques restantes. Una vez que se han expuesto los conceptos básicos y la teoría de la inclusión de estos elementosen el análisis estructural proseguimos a la aplicación práctica mediante el uso de algunosejemplos que nos permitirán llevar a cabo el análisis comparativo del que es objeto esteproyecto. Finalmente presentamos el análisis de los resultados y las conclusiones que obtuvimos de los ejemplos y análisis realizados.