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In the field of structural safety, flat slab buildings represent a relevant category of construction. These buildings stand out for their constructive advantages and architectural versatility, which made them a popular choice between the 1970s and 1990s, especially in areas of high seismic risk such as the Pacific Ring of Fire. Currently, there are regulations that restrict the construction of this type of buildings in areas vulnerable to earthquakes, seeking to protect the lives of the inhabitants and the structural integrity of the buildings. The objective of this research is to implement and validate a macromodel for seismic evaluation by nonlinear static pushover analysis of flat slab systems. This will allow determining the structural behavior of these buildings against lateral loads by establishing the predominant failure modes. The validation of the macromodel is carried out using OpenSees structural analysis software and full-scale experimental data performed by recognized researchers. The focus of these experimental campaigns is to evaluate the structural performance of internal connections between a flat slab and a column subjected to lateral loads. Two macromodels are developed with the purpose of capturing the proposed failure modes; subsequently, pushover curves of the structure are obtained to indicate the general damage state of the system. Finally, stress-strain curves are analyzed to verify the failure mode produced.

Ecuador is in the Pacific Ring of Fire. It is a zone with high tectonic activity. Therefore, its population and infrastructure must be prepared to face seismic environments. It is the case of Cuenca, a city recognized by UNESCO as an Intangible Cultural Heritage of Humanity in 1999 due to its historic architecture with masonry buildings dating back more than a century. Between the 1940s and 1980s, the use of unreinforced masonry-bearing walls combined with flexible floor systems became popular in the construction of buildings. However, the lack of confinement and reinforcement in this type of structure results in poor seismic behavior compared to modern construction techniques. It emphasizes the need to evaluate their seismic capacity. In the present work, MNR buildings are characterized as a function of time and size, considering geometrical aspects such as the distribution of openings, inter-story heights, walls, and joint thicknesses. In addition, the mechanical properties of brick, mortar, and masonry are analyzed and characterized. Nine models representing the different construction periods were studied using two-dimensional macro-elements. Also, a family of capacity curves using nonlinear static analysis is studied. Subsequently, limit states are analyzed, and damage thresholds are established according to the NTC2018 standard. The results are analyzed in terms of ductility and maximum base shear.

In the present work, an analysis of the influence of openings on the seismic behavior of confined brick walls was carried out, using the ideal methodology to carry out nonexperimental comparative studies and thus obtain idealized pushover curves and a set of formulations selected from an important corpus of experimental and numerical simulation works of confined walls and masonry infilled frames subjected to the action of increasing lateral loads. This project focused on the influence of door and window type openings in the reduction of elastic lateral stiffness and lateral load resistance capacity, through a comparative analysis between the real values and calculated numerical values, the set of optimal formulations applicable to the typical confined masonry typologies of the city of Cuenca. The data obtained and tabulated were processed, in order to present the selected formulations. As a result, organized tables are displayed; with a brief description, information on the authors, year of publication and reference, as well as information on the masonry models in which said formulations were applied; the type of brick units (solid or hollow), opening variations (size, type and position), the type of lateral loading and the typology (infilled frame or confined masonry)

Santa Ana de los Cuatro Ríos de Cuenca, the capital of the Azuay province was founded on April 12, 1557. Since then, there have been many changes in the urban sprawl of the city and particularly in its Historic Center (CHC) (Jiménez, 2002). Because the city is located in an area of high seismic threat (Jiménez, Cabrera, Sánchez, & Avilés, 2018) and considering that the building material that was imposed since 1970 in the CHC has been brick (Jiménez, 2002), is taken as a working basis: Evaluación sísmica de edificios de mampostería no reforzada típicos de Barcelona: modelización y revisión de la aplicación del Método del Espectro de Capacidad (Jiménez, 2016). This research is used to compare the results obtained by the Red Sísmica del Austro (RSA) on prototypical unreinforced masonry buildings (URM) of the Cuenca Historic Center (CHC) (Jiménez, Cabrera, Sánchez, & Avilés, 2018), where the almost independent behavior of the resistant walls of the building is evident (modal behavior) as indicate Lagomarsino, Camilletti, Cattari, & Marino (2018) for irregular URM buildings with flexible floors, making it difficult to assess their seismic response using methodologies based on nonlinear static analysis (Quagliarini, Maracchini, & Clementi, 2017). On this basis, it is proposed to identify the influence of some geometric variables and mechanical characteristics on the building on the global dynamic behavior of an URM structure in terms of the form of its vibrational modes. Consequently, the dimensions of the spans between the walls, the symmetry of the building in terms of the stiffness of its structural elements and the transmission of lateral loads due to the existence of flexible floor diaphragms are analyzed

The Ecuadorian city Cuenca was declared Cultural heritage of Humanity since 1999. The main reason for this award is due the great variety of colonial buildings and the history inside each one of them. However, most of them buildings are build with adobe, this material have some features as low manufacturing costs and termal isolotation. On the other hand, the main risk with this type of construction is given by its high vulnerability to seismic events. Under this premise, in this thesis an evaluation of adobe buildings is made. Firstly, the behavior of adobe walls in the plane is validated, through methods that capture the deformation that occurs in the wall when subjected to a horizontal load. Secondly, in an extensive bibliographic review several trials were found to validate the chosen method, highlighting the equivalent gantry macroelement method. For the last one, there must be formulations required by the method for both shear and flex failures. In the literature there is only one formulation applied for shear failures, for this reason in this thesis the formulation verified in other works in brick masonry is validated in adobe. Finally, using the Ruaumoko program, the walls found are modeled and then compared with the results obtained.

The present research is focused on the study of the behavior of the building of the Empresa Eléctrica Regional Centrosur (EERCs), according to the modal parameters that govern its movement in the face of a seismic event, with a focus on the monitoring of structural health. For the analysis of the building, a structural survey is performed, focusing on the guidelines set forth in FEMA 154, starting with a visual inspection and determining the geometric dimensions of the structure. Then, the mechanical characterization of the building's concrete elements is carried out, 4 tests are performed (scanning of reinforcing steel, rebound number, extraction of concrete cores, resistance test) in the field and in the laboratory, focused on determining the concrete's resistance to compression; the influence of the nominal size of the coarse aggregate on the values obtained was determined. For the modal analysis, the structure is modeled by means of the program Etabs 17, seven models are proposed including gradual changes between these, depending on: the geometry of the building, the permanent loads such as walls and finishes, and the cracked sections of the concrete elements. In these analyses, the influence of the walls and cracked sections on the calculated vibration modes is studied. It was observed that generating loads on slab elements and the further away from the center of mass they are, the more flexible the structure becomes. Finally, for a study of an operational modal analysis, an instrumentation plan based on uniaxial, biaxial and triaxial sensors is proposed.

Ecuador is a country located in the Pacific ring of fire, it has high seismic risk and therefore the buildings are subject to seismic solicitations. Hence, cities such as Cuenca are subject to strong telluric movements due to the presence of the Girón fault and because it is a city whose urban layout conforms to the orthogonal plan established 400 years ago and whose most common buildings are made of masonry, which have remained over time, being rebuilt, restored and reinforced to maintain colonial architecture and therefore form part of the Historic Center, which have allowed to be recognized as a Cultural Heritage of Humanity. Therefore, the entire city and especially the Historic Center of Cuenca (CHC) is very vulnerable to earthquakes as found in the P-BID 400 project (1999-2002): “Peligro Sísmico en el Austro y Vulnerabilidad Sísmica en la Ciudad de Cuenca”, leaded by Red Sísmica del Austro de la Universidad de Cuenca (Jiménez, 2002). In this context it is necessary to carry out a seismic evaluation of the buildings with the typologies present in the CHC. In this work the seismic behavior of brick masonry buildings with tie beams (MNRL-VA) was studied. For this, 3 prototype buildings were defined depending on the construction area and a parametric study was carried out, varying the thickness of the walls, the quality of the materials, the stiffness of the floor and the influence of reinforcement of the tie beam, other masonry typologies were also modeled: unreinforced masonry (MNR) and confined masonry (MC) to see the influence of typology on the seismic-response of buildings. The models were implemented in the 3Muri program that allows pushover curves to be performed and that uses the equivalent frame model with macroelements, model proposed by Lagomarsino et al. (2013). Since this typology does not present studies carried out in the region, a bibliographic review was carried out in order to obtain information on the use and behavior of the tie beam in buildin

The main purpose of this work is to identify patterns and trends in buildings intervened in the historic center of Cuenca such as: construction styles, construction typologies, geometric characteristics, organization of walls, materiality of floors and roofs, masonry resistance, etc. This project is important because it will serve as a study base or starting point for other projects that require information on the architectural, typological, geometric or resistance characteristics of the masonry of buildings in the historic center of Cuenca. The results show that there is no trend marked with the interventions with respect to changes in the materiality of floors and roofs due to the regulation and intervention permits issued by the Directorate of Historic and Patrimonial Areas of Cuenca in order to conserve the patrimonial value of the buildings. With regard to the organization and modification of walls, it is established that in most cases the percentage value of both the continuity and the alignment of walls in the plant is slightly increased, so that the conditions are improved for an idealization and structural benefit. It is also important to emphasize that in the results obtained from the compressive strength of adobe and brick masonry, it is established that as buildings are more modern, their materials have greater strength but with a variation of increase in strength for the adobe for the brick.

Cuenca is a city located in an area of high seismic risk, with a large number of heritage houses built with the type of confined masonry (CM). CM walls are commonly constructed of brick units joined by cement mortar, confined with columns and reinforced concrete beams (RC) made in situ. There is a wide variety of modeling techniques developed for the analysis of this type of structures, with different degrees of refinement and precision. Based on the research carried out regarding the modeling techniques, macromodels were chosen, which are easy to apply and do not require a very high computational cost when compared with micromodels. This work is focused on the implementation of a macromodel proposed by Torrisi (2012), for the case of full CM walls, which was designed under the considerations of the equivalent diagonal model constituted by three compression diagonals, and thus represent the behavior of the masonry wall and the behavior of the confining elements, when subjected to lateral loads. The Ruaumoko program was the tool used for modeling and pushover analysis, obtaining satisfactory results in terms of initial rigidity and maximum capacity of the walls tested.

Cuenca is a city of the Southern Center of the Republic of Ecuador and is the capital of the province of Azuay. It is located on an area of high seismic hazard (Jiménez Pacheco, Cabrera Cajamarca, Sánchez Beltrán and Avilés Tenorio, 2017, NEC, 2015). The entire city, and in particular its Historic Center (CHC) is highly vulnerable as noted in the P-BID 400 project (1999-2002): Peligro Sísmico en el Austro y Vulnerabilidad Sísmica en la Ciudad de Cuenca, carried out by Red Sísmica del Austro de la Universidad de Cuenca (RSA) (Jiménez, 2002). Under this context, it is necessary to carry out a seismic evaluation of the four general building typologies of the CHC. In this work, the seismic behavior of buildings built with unreinforced masonry (MNR) was studied. To do this, a building model that represents the materials and the geometry of all its components is defined. This model was implemented in the Ruaumoko program, capable of obtaining the capacity curve (pushover). In order to cover as many results as possible, a parametric analysis was carried out, varying the thickness of the walls, the stiffness of the floor and the quality of the materials. In order to establish global damage assessment strategies in nonlinear static analysis, a review of recent literature was conducted

The city of Cuenca is located on an area with high seismic hazards, PGA=0.25g, according to the Ecuadorian Construction Standard. The history of seismic activity in the sector reveals disasters caused by at least one earthquake of magnitude 7 (February 1913), implying probable seismic scenarios to arise in different construction typologies of the city, such as structures reinforced concrete. Historically, since of the eighties, the structures respond to breach system and flat slab. The structure plant configuration has not been of great relevance at the moment of analyzing its behavior in front of an earthquake, for which it expects buildings with different degrees of asymmetry, leading to torsion problems in plant. The methodology of consideration of the torsion in plant is presented based on a statistical analysis of buildings with a frequent plant configuration, through schemes and architectural plans, establishing typical patterns of distribution of structural elements and indices that indicate the potential torsion in plant, for a future seismic evaluation by non-linear static methods, -pushover-, that consider the torsional effect produced by the movement of the soil, as a strategy for assessing the performance of buildings. The result is the point of intersection between the capacity curve obtained from the pushover analysis, -relationship between the basal shear and superior displacement-, and the elastic response spectrum. Subsequently, a comparison is made between the methods to define the best relevant methodology to the cases of the city of Cuenca.

The buildings constructed in the 80's in Cuenca, with design deficiencies due to lack of control, are susceptible to shear failure in their elements during an earthquake, being a critical problem when it occurs in columns. Due to the important number of these buildings in the city, in the present work their capacity is determined and their seismic performance is evaluated by means of current nonlinear static seismic analysis methods. For this, it is considered a 4-story reinforced concrete building representative of the city, with detailing of reinforcement in beams and columns according to the trends and constructive criteria of the time. The performance is determined by the Capacity Spectrum Method proposed by the FEMA 440 manual, which starts from the capacity curve of the structure obtained by a non-linear static analysis that includes the shear modeling, and the response spectrum of the study zone. The results obtained are: the capacity and the point of seismic performance for 3 representative cases of the epoch obtained from historical information. In addition, the contribution of the transversal reinforcement correctly detailed to the ductility of the structure is demonstrated from a parametric analysis that considers as variables the separation and the diameter of the transversal reinforcement in beams and columns. Finally, an estimate was made of the damage that the structure will suffer through the damage thresholds proposed in the project of the European Commission RISK-EU.

A common premise of the buildings seismic assessment is the occurrence of a global failure mode governed by in-plane failure mechanisms of walls. In the case of the traditional unconfined buildings of adobe or brick, this statement is not realistic, studies of post-seismic damage observation reveal that in these buildings the common failure mode is governed rather by out-of-plane failures mechanisms in walls. Due mainly to low connection degree between walls and between walls and floor. Thus, this work carries out of the out-of-plane failures in walls, assuming as object of study typical dwellings of the urban and rural sector in Cuenca. In the first instance, from a typological studies of adobe dwellings in Cuenca, a set of walls was stablished as study. In the second instance, based on the failure catalog revision proposed by D’Ayala y Speranza (2003), defines the most probable failure modes in function of geometric characteristics of walls. In terms to the seismic assessment of walls followed an analogous methodology (Cattari et al., 2015) to the Capacity Spectrum Method (Global in-plane failure), which consists on obtaining the performance point since the crossing between the capacity curve (represented by an effective secant period) and the demand curve (design spectrum). The obtained capacity curve is based on a tri-linear model (Doherty et al., 2002) which considered boundary conditions, connection degree, geometric parameters and collapse multipliers to represent out-of-plane failures. The seismic demand is obtained according to recommendations of the NEC-15 (2015a) for different levels of acceleration and verifying a reduction by overdamping due to incursion in the inelastic range. The final results, were presented through flow diagrams based on determinate the dominant failure mechanism in function of different geometric parameters and boundary condition of walls. This project took place within the framework of seismic vulnerability study of built heritage

Equator, located in the Pacific Ring of Fire, registers moderate to high seismic hazards. April 16th of 2016 in the coastline on Pedernales city the country suffered a 7,8 magnitude earthquake that coasted 663 lives and millions in material loss. One of the most destructive effects of seismic activity is the induction of landslides. This work studies Guarumales landslide, located in the oriental foothills of the Andes Mountains. There lies the Electric Corporation of Equator (CELEC) campsite for one of the most important hydroelectric projects in the country, Project “El Molino”. The fundamental methods for slope stability evaluation are limit equilibrium analysis and stress-deformation analysis. The most used procedure is the pseudostatic analysis, which is based in limit equilibrium. The objective of this study is to determinate the seismic coefficient for a pseudostatic slope stability analysis for Guarumales landslide. Usually the seismic coefficient is a fraction of the maximum horizontal acceleration. Bray and Rathje (1998) propose that fraction is a function of the ground motion parameters (magnitude, distance, duration of the earthquake and mean period of the earthquake). The American Society of Civil Engineers Los Angeles Section Geotechnical Group recommends this criteria to reduce unnecessary conservatism. The obtained seismic coefficient is lower than the previously used due to the reduction of uncertainties that the over simplification of a dynamic phenomenon to a static analysis. This method is recommended for slope analysis, however further prospection is needed if actions are meant to be done.

Cuenca is a medium city located on an area susceptible of moderate to severeseismic movement. The historical seismicity of the region reveals at least one earthquake that caused serious damage in the city (February 1913; estimated magnitude: 7). This dangerous context and the fact that the built heritage of the city (in particular the historical center) is not provided with the appropriateearthquake-resistancesupplies, creates a scenery of seismic vulnerability. In relation with the built heritage of the city, during the seventies and eighties, porticoedbuildings of reinforced concrete of low-rise were very popular. In this context, this projectfocuses on the seismic evaluation of a four-storyporticoedbuilding of representative features (global geometry, dimensions of members and amounts of reinforcement) of the existing buildings in the city. The proposed building was conceived with fully symmetrical floor. The seismic evaluation was conducted taking into account the guidelines of the capacity spectrum method proposed by the FEMA 440 manual, based on a pushover analysis. The model proposed is in line with the inelasticity concentrated models, considering only the inelastic behavior to the bending of beams and columns. The Ruaumoko program was the tool used for modeling and the pushover analysis, as well as the multispring item, the basis of the conformation of such members. Beginning with the prototype building, there were considered four cases of study according to the resistance of the materials and the hysteretic global model. The main results obtained from the application of the capacity spectrum method FEMA 440 were the maximum displacement demands of the cases studied, these are compared and analyzed. Special emphasis was placed on the collection of bends force-displacement of beams and columns, and the implementation of the capacity spectrum method FEMA 440.

Currently, there are very few programs specialized in seismic analysis of unreinforced masonry buildings. Most studies have focused on the seismic behavior of the walls or (in a 3D level) have not integrated the flexibility of the floor system in the problem. In this context, two were the primary objectives of this work: 1) develop a model for nonlinear static analysis of unreinforced masonry buildings considering the flexibility of the floor, 2) study the influence of the stiffening of the floor system in the global seismic performance of such buildings. A six-story prototype building, representative of the first period of the Eixample-Barcelona (1860-1880), was adopted as case study and benchmark. This building was generated from the review of several documentary sources. As regards the seismic action, it was assumed one of the analytical formulations of the RISK-UE project, covering both deterministic and probabilistic scenarios. Thus, on the basis of the premise of a second global failure mode, the proposed model falls within the equivalent frame approach. The modeling of the walls consisted in the assembly of vertical and horizontal macro-elements (piers and spandrels) with rigid links. The floor system, belonging to the type of unidirectional floors, was modeled as aggregation of diaphragm macroelements with a simple shear behavior. All macro-elements, those that constitute the walls as well as the floor system, were developed with spring-elements. The construction of the model followed a strategy of modeling and validation by stages, from the 2D equivalent frame model until the integral model of the prototype- building. As regards the analysis of the influence of the stiffening of the floor system, it was based on conventional methods of stiffening, from two basic variants of the prototype-building defined in function of the floor system: jack arch masonry slab and timber floor, typical in the Eixample’s buildings. On the basis of a sensitivity analysis, the, Actualmente, son muy pocos los programas que se especializan en el análisis sísmico de edificios de mampostería no reforzada. La mayoría de trabajos se han concentrado en el comportamiento sísmico de las paredes o (a nivel 3D) no han integrado la flexibilidad del sistema de piso en el problema. En este contexto, dos fueron los objetivos fundamentales de este trabajo: 1) desarrollar un modelo para análisis estático no lineal de edificios de mampostería no reforzada que considere la flexibilidad del sistema de piso, 2) estudiar la influencia de la rigidización del sistema de piso en el desempeño sísmico global de tales edificios. Como casobase de estudio se asumió un edificio-prototipo de seis pisos, representativo de la primera época del Eixample-Barcelona (1860–1880), el cual se generó a partir de la revisión de varias fuentes documentales. En cuanto a la acción sísmica, se asumió una de las formulaciones analíticas del proyecto RISK-UE, abarcando tanto un escenario determinista como probabilista. Así pues, a partir de la asunción de un segundo modo de falla global, el modelo propuesto se inscribe en la aproximación de pórtico equivalente. La modelización de las paredes consistió en la ensambladura de macro-elementos verticales y horizontales (pilares y vigas-dintel) mediante vínculos rígidos. El sistema de piso, perteneciente al tipo de pisos unidireccionales, se modelizó como agregación de macro-elementos diafragma con un comportamiento de corte simple. Todos los macro-elementos, tanto los que conforman las paredes como el sistema de piso, se elaboraron con elementos tipo resorte. La construcción del modelo obedeció a una estrategia de modelización-validación por etapas, a partir del modelo 2D de pórtico equivalente hasta el modelo integral 3D del edificio-prototipo. En cuanto al análisis de la influencia de la rigidización del sistema de piso, se basó en métodos convencionales de rigidización, a partir de dos variantes básicas del edificio-prototipo establecidas, Postprint (published version)

The city of Cuenca is located in an area of moderate high seismic risk, so there is a need for a study and analysis of the buildings that are in it, therefore our project focused on the nonlinear static analysis of two walls - prototype.For a theoretical study of the mechanical properties of both the masonry, as the elements that form, literature studies by several authors in the city of Cuenca it was used. In this project the failure mode was excluded bending and focused on the failure modes by cutting, in-filled walls and walls with openings.With the information obtained nonlinear models for two walls-prototypewas developed. These models are approximations of concentrated inelasticity for pushover analysis. For the development of this model, a system of springs, where each wall segment was represented by a spring cutting, with the respective physical and mechanical properties said wall segment was used. The maximum lateral resistance of each spring are calculated from empirical equations presented by different authors. The developed model was implemented in the Ruaumoko program. Through this study the seismic behavior of the prototype walls in terms of the pushover curves are analyzed. In addition, a comparative analysis of walls without openings are held, as well as implemented a model of masonry wall with or without columns confinement.