Maestría en Ingeniería Civil con Mención en Estructuras Metálicas

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Capacidad sísmica residual de un edificio reforzado con perfilería metálica usando análisis no lineal en la ciudad de Ambato
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022) Cisneros Sánchez, Francisco Vinicio; Peñafiel Valla, Lourdes Gabriela
To start with the execution of this project we took into account a building located in the city of Ambato, province of Tungurahua, this was born due to the informal construction and non-compliance of structural plans and poor quality of materials. The structure was built of reinforced concrete, reinforced with the method of jacketed columns and beams on metal structure, it has 5 floors and its use is residential. The building was studied the different behaviors that it could have with an Occasional, Frequent, Rare and Very Rare earthquake, as recommended by the NEC-2015 through static and dynamic analysis, verifying its current design conditions and concluding that the building complies with current structural design regulations. The seismic capacity of a structure refers to the total energy that it is capable of dissipating during a seismic event and the residual seismic capacity corresponds to the energy that the structure can still dissipate after a seismic event, under which it has not exhausted all its capacity. In the present investigation, the capacity indexes of the building were determined without reinforcing its mezzanine floors, in this behavior there would have been severe damages in a design seismic event and with reinforcement it could have light damages. The seismic capacity reduction factor calculated with the dissipated energy method by the Japanese Damagexviii Assessment Guide (JBDPA 2015) was determined that for an earthquake Frequent Tr=72 years, Occasional Tr=225 years the damage class would be of a level I that could appear fine cracks smaller than 0, 2 mm and in a Rare Tr=475 years and Very Rare Tr=2500 years earthquake, the damage class would be of a level II where the members of the structure could yield and there could be visible cracks at their ends between 0.2 mm to 1.0 mm wide. In order to complete the study, the costs of rehabilitation and maintenance were determined by means of FEMA P-58 in each seismic event, concluding that currently in a frequent, occasional and rare earthquake it is recommended to repair it, but in a very rare seismic event the cost is similar to the current value of the structure and it is recommended to demolish it.
Diseño y análisis del parqueadero central de la ciudad de Ambato de hormigón armado y estructura metálica con el uso de elastómeros en la cimentación
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022) Sánchez Tenesaca, Estefanía Jacqueline; Fiallos Condo, Jéssica Tatiana; Chérrez Gavilanes, Diego Sebastián
In the present research work several factors are taken to determine the seismic safety of buildings, materials such as elastomers have been used for structural protection. The design and analysis of the central parking lot of the city of Ambato of reinforced concrete and metal structure with the use of elastomeric insulators in the foundation helps to improve seismic behavior. A modeling was carried out using software analyzing each of the structural elements, especially the behavior of the foundation. Structural and economic analysis shows that a structure equipped with elastomeric insulators in the foundation reduces its initial investment in the structural system since these are responsible for dissipating much of the energy that enters the system so the sections of the structural elements are reduced which implies savings. Its benefit is given in the long term reflected in the performance that the structure can achieve. In the analysis torsional distortion was visualized, we did not find the use of prequalified connections, factor of importance of the structure equal to one, vibration modes insufficient for a minimum mass participation of 90 percent, so we performed a verification through a linear analysis and a static nonlinear analysis with a factor of importance I = 1.5, , additionally, we must analyze the essential structures by means of a non-linear analysis for a return period of 2500 years as stipulated in the NEC SE DS 15. Therefore, this research determines the level of structural performance, as stipulated in the Ecuadorian Construction Standard in force, in the chapter of seismic design thus deducing that it was necessary to implement a structural reinforcement system, which at least allows the structure to remain at a level of (Life Safety) LS which is what the standard requires us.
Análisis del comportamiento estructural del centro integral y cultural de los gobiernos parroquiales rurales de Pastaza en estructura metálica con el uso de aisladores elastoméricos, en la ciudad del Puyo, cantón y provincia de Pastaza
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022) Velasteguí Lara, Janne Carolina; Cañizares Ortega, Freddy Fernando
The present research work performs an analysis of the structural behavior of a six-story building in metallic structure with the use of elastomeric seismic base isolators, which allows us to perform a comparative analysis of the structural behavior through the vibration periods that directly influence the floor drifts as displacements, of an isolated and non-isolated structure. It was performed prior to the analysis of several structural probabilities, seeking that the structure complies with the minimum seismic resistant requirements suggested by the Ecuadorian Construction Standard "NEC 15", as well as the Complementary Technical Standards for Earthquake Design, "NTC-DS-2017", the Chilean Standard "NCH-2745", the American Institute of Steel Constructions "AISC 341- 16" code and the American Society of Civil Engineers "ASCE 7-16, ASCE 41-13, which, by their design characteristics, provide seismic resistant safety. The mathematical model for the calculation was made based on the characteristics of the architectural and structural drawings, making a stabilized structure obtaining floor drifts and displacements in accordance with the requirements of the NEC-15 recommendations, consequently, the seismic isolation was made through the pre-dimensioning and design of the elastomeric base isolators with lead core type LRB. Subsequently, the scaled accelerograms were entered into the structural model of the software, in order to establish a nonlinear dynamic time-history analysis and to obtain a real analysis of the structure, a nonlinear static analysis was performed. With the data entered into the software, results were obtained for a building without isolation, including: vibration periods, displacements, floor drifts, basal shear, accelerations, overvoltage of the structure and energy balances; likewise, the basic seismic isolation was implemented in which the expected results were obtained, in order to perform a comparative analysis of a structure with and without isolation.
Propuesta de reforzamiento de vigas de alma llena de puentes metálicos con fibra de carbono y resina epóxica
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022) Peña Jordán, Francisco Agustín; Yunapanta Velasteguí, José Luis; Guerra Avendaño, Oswaldo Marcelo
Full web steel girders are used for vehicular bridges. These structural members are subjected to cyclic loading, which causes damage over time. The bridges are designed for a service life of at least 50 years, which is why they require maintenance, either for repair or repowering. An alternative is the reinforcement with carbon fiber and epoxy resin sheets. With the present research, a three-dimensional mathematical model was obtained that adjusts to the real behavior of beams composed of steel and concrete, reinforced with carbon fiber. The research was developed by applying real bending tests, and through finite elements in ANSYS RESEARCH - WORKBENCH software. The results between these tests of the composite beam were compared and a max difference of 4,8303 mm was obtained. The three-dimensional model obtained can be used to estimate the reinforcement of full web steel beams used in steel bridges.
Análisis estático no lineal (Push Over) de los talleres de la Facultad de Ingeniería Civil y Mecánica y de la Facultad de Ingeniería en Sistemas Electrónica e Industrial, con aisladores sísmicos, ubicadas en el campus Huachi de la Universidad Técnica de Ambato
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022) López Sánchez, Byron Leonardo; Ureña Aguirre, Maritza Elizabeth
This research work presents a comparative analysis of the structural behavior of a conventional structure and another with the implementation of seismic isolators, which are devices that allow the building to deform elastically and dissipate energy during the occurrence of earthquakes of considerable magnitude. The structures analyzed were the workshops of the faculties of: Civil and Mechanical Engineering and Systems, Electronics and Industrial Engineering and they are classified as special according to the Ecuadorian Construction Standard (NEC 2015), and present a structural system of special earthquake resistant gantries made of hot rolled steel with stiffening diagonals, they are also used as laboratories for the production area and as a higher education center.xxiii As a first study, a linear analysis of the structures was performed to verify their current state by analyzing their vibration period, displacements and permissible drifts, then a non-linear static analysis was performed to determine their seismic performance, and then the isolation system was pre-dimensioned. It was designed taking as a priority the ASCE/SEI 7-10 standard, the dead loads of the building plus 30 percent of the live load above the isolation system and based on the information provided by the manufacturer. It should be taken into account that there are a large number of options of anti-seismic devices to improve the performance and behavior of a structure; in this case study, the lead core elastomeric isolator (LRB) was chosen. Subsequently, all the established limits such as drifts, shear and displacements were verified, taking into account the provisions of the Ecuadorian Construction Standard. For the workshop of the Faculty of Civil and Mechanical Engineering with isolated base, the floor drifts were reduced by 64 percent compared to the structure without isolation, for the basal shear and horizontal displacements a reduction of 73 and 51 percent respectively, likewise for the workshop of the Faculty of Systems, Electronics and Industrial Engineering the floor drifts, shear and displacement were reduced by 69, 74 and 63 percent respectively.
Desarrollo de un software específico para el diseño de conexiones de arriostre o viga-columna para pórticos especiales arriostrados concéntricamente, conforme a la normativa ANSI/AISC 341 -16
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) López López, Liliana Lizbeth; Pico Núñez, María Fernanda; Medina Robalino, Wilson Santiago
The present research project has as purpose the codification of a specific software for bracing connections or beam-column connections design for steel special concentrically braced frames (SSCBF). It allows us to design in a quick and safe way the simple beamcolumns (bolted) connection, welded beam-column connection, double braced beam column (welded) connection, X brace-beam (welded) connection, simple beam-column (bolted) corner connection, and simple beam-column (welded) corner connection. For the design of the different connections, they were analyzed by ANSI/AISC 341-16 Standards criteria. From it the calculation equations for a design by capacity were taken. For the development of the software, we started with the manual calculation of the different connections, with this the software programming code was developed and at the same time the graphic interface for the visualization of the results was created. For the veracity of the SCBF DESIGN CONNECTION software, the results obtained by the developed software were compared with the manual method; resulting in a margin of error of less than 1.50 percent, thus verifying that the results obtained by the software are reliable.
Caracterización de elementos estructurales de acero que hayan sido expuestos a diferentes tiempos y temperaturas debido a un incendio
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) Guamanquispe Vaca, Fernanda Patricia; Espín Lagos, Segundo Manuel
In the present investigative work, different structural elements such as columns, beams and steel straps ASTM A 36 exposed to flagella were characterized, considering different times and temperatures of exposure; For the experimental part, the conditions were simulated by using a conventional furnace in which several samples of steel and combustible material were placed, trying to simulate a real scourge, after which samples were taken at temperatures of 600, 800 and 1000 degrees celsius and exposure times of 30, 45 and 60 minutes, to which hardness and macroscopy tests were carried out in the materials laboratory of the Faculty of Civil and Mechanical Engineering and to be able to determine the mechanical properties of the material subjected under these conditions and compare them with those of the unexposed material; By means of the hardness it was possible to determine the ultimate resistance of the material and from the percentages of Ferrite and Perlite it was also verified that the ultimate resistance toxvi traction increased by 9-10 percentage since the samples were cooled by means of a cold water jet, a condition that occurs when a fire is extinguished; Although it is true that the mechanical properties of the specimens did not vary significantly, from the bibliographic review it was possible to determine that in real time of the flagellum, the resistance to creep decreases in inverse proportion with the temperature, so it is possible that the structure collapses. At that time, from the aforementioned, it can also be said that if the structure does not collapse during the fire and is still standing and without deformations in the structure, it can continue to provide service; Finally, after the analysis, it was possible to conclude that the mechanical properties of the structural steel elements at the time of the fire depend on the time and temperature of its exposure.
Desarrollo de un software para el diseño de vigas y columnas metálicas de acero conforme a la normativa AISC 360-16
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) Zambrano Salazar, Luis Leonardo; Peñafiel Valla, Lourdes Gabriela
In the present research project, the graphical interface and the coding of a calculation software for the pre-design and design of steel beams and columns were carried out in accordance with the AISC 360-16 standard, through the use of a programming software and its tool guide. The software allows us to obtain pre-design sections for both beams and columns, which were verified in the design process, proven that they resist the requests to which they are exposed to the structure under analysis, all this is done by entering data such as: geometric configuration of the structure, load states and properties of the steel to be used. For the development of the software, it has been necessary to carry out a bibliographical investigation where the LRFD (Load and Resistance Factor Design) method is extended, for the design of steel beams and columns, which is approved by the American Institute of Steel Construction. (AISC 360-16) and the Ecuadorian Construction Standard (NEC 2015). Once the calculation method was determined, the algorithms necessary for the software coding were developed, once defined, the graphical interface of the same was elaborated. Once the development of the software was completed, a debugging of the programming code was carried out where the calculation algorithms were optimized to achieve a better and faster operation of the software. The validity of the developed program will be verified through a comparison of the results obtained through the software, manual calculations and a commercial program, obtaining an error rate of less than 0.8 percent, with which it was possible to verify that the calculation values obtained through the software developed in this research they are valid and reliable, thus achieving an optimization in the calculation time and precision in them, since being an automated software the human factor capable of committing involuntary errors during the manual process is eliminated. of calculation.
Análisis de los procesos de soldadura SMAW, GMAW Y FCAW en varillas de acero estructural corrugado ASTM A706, mediante juntas a tope con bisel en V simple y doble, y su incidencia en las propiedades mecánicas de la junta soldada
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) Armas Real, Daniel Alberto; Vaca Ortega, Wilson Henry
In order to provide an alternative to the traditional method of overlapping between reinforcing steel rods, it is intended to analyze some applicable welding processes to join reinforcing steel rods in the present work. The base material corresponds to reinforcing steel ASTM A706, the same one that is marketed nationally by the main steel mills and whose main characteristic is its good weldability. The welding processes used were the SMAW, GMAW and FCAW processes, and the joints used were single and double beveled butt joints for a rod diameter of 14 mm. The weld seams were made by a qualified welder and the welding processes were qualified by a welding inspector. The destructive tests carried out were the tension and macroetch tests, while the non-destructive test carried out was the penetrant dye test, which was carried out based on the structural welding code and based on structural welding code – steel reinforcing bars. Once the data was tabulated, the type of joint that presented the best mechanical properties for the FCAW process was the double V-bevel butt joint, while for the SMAW process good results were obtained for both types of bevel, however, after performing the analysis of welding costs, the type of butt joint with double V bevel was the one that reached the best cost-benefit ratio, despite the fact that compared to the other processes it was the most expensive; an additional benefit of this process is that it does not require an external shielding gas. The GMAW process, despite complying with the requirements of the code, did not obtain a good result in the percentage of elongation; Regarding the FCAW process, additional specimens were made to carry out the macroetch tests, because if a correct cleaning between passes is not carried out and the correct parameters are not used in the welding, a lack of fusion is obtained between the base metal and the base metal. input.
Estudio de conexiones precalificadas y su incidencia en el diseño sismo resistente de edificaciones irregulares
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) Sánchez Guevara, Nelson Hernan; Guerra Avendaño, Oswaldo Marcelo
Ecuador es un país de alta actividad sísmica. En el año 2016 se vio afectado por un evento sísmico el cual fue generado a raíz de un fenómeno producido entre la subducción de la placa de Nazca y la placa Sudamericana, lo cual dejó cuantiosas pérdidas económicas, humanas y de edificaciones, siendo esto un factor principal de suma importancia para la investigación en el campo de la ingeniería estructural. En el presente trabajo de investigación se realizó un análisis sismorresistente de tres edificaciones irregulares de baja, mediana y gran altura, conformadas por un sistema resistente a carga lateral de pórticos especiales resistentes a momento SMF de acero estructural, compuestos por columnas de tipo HEB y vigas IPE. Para empezar el proyecto se realizó un análisis de la configuración estructural de las edificaciones planteadas para luego aplicar las consideraciones que establece la norma ecuatoriana de la construcción para tomar en cuenta los casos correspondientes de irregularidad en las edificaciones tanto en elevación como en planta. Luego se procedió a resolver las estructuras mediante un análisis estático y dinámico lineal, logrando obtener resultados que muestran un adecuado comportamiento estructural y cumplan con los chequeos obligatorios normativos, como son el chequeo de las derivas de piso, la verificación del criterio columna fuerte – viga débil y el diseño de sus elementos estructurales. Las conexiones de acero son de gran importancia para garantizar el comportamiento sismorresistente de las edificaciones. En zonas de alta sismicidad es necesario utilizar sistemas de pórticos especiales resistentes a momento y que sus conexiones sean precalificadas, lo que garantizará la formación adecuada de las rotulas plásticas contribuyendo a obtener como resultado un apropiado comportamiento en el rango no lineal. Una vez finalizado los diseños estructurales de las edificaciones planteadas, se procedió a diseñar dos conexiones precalificadas como son la Conexión de Placa de Ala Empernada (Bolted Flange Plate BFP) y la Conexión de sección de viga reducida (Reduced Beam Section RBS) descritas en la norma AISC 358-16. Las conexiones se diseñaron de forma manual cumpliendo todos los parámetros establecidos en la normativa AISC 358-16 para finalmente realizar su respectiva validación y comparación de resultados obtenidos mediante el uso de un software especializado en el diseño de conexiones de acero obteniendo resultados similares.
Reducción de la vulnerabilidad sísmica de estructuras ocupacionales de acero en el cantón Ambato
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) Jiménez López, Geovanny Gabriel; López Villacis, Gonzalo Eduardo
In this degree work, a seismic vulnerability study is carried out for two representative structures that constitute the typical occupation given to steel buildings constructed within the urban area of Ambato Canton. These buildings, according to the NEC-2015, are categorized as essential and special type structures respectively. As an initial part, a preliminary design check was performed using the design spectrum prepared according to the standard for this sector, where compliance was reviewed in terms of floor drifts, soft floor and torsion in plan. Subsequently, by means of a nonlinear pushover static analysis, the capacity of the structure and its performance level in the presence of moderate and extreme earthquakes were determined. Likewise, certain influences of the infill masonry used in this type of structures were determined, and finally, according to the performance obtained, a reinforcement was proposed through the use of concentric diagonals and energy dissipaters in order to improve their performance level and avoid their collapse.
Estudio de pórticos arriostrados concéntricamente en V, V invertida y arriostramiento en K y su incidencia en el diseño de un edificio en acero de 7 pisos
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-03) Salinas Villegas, Edisson Xavier; Espín Lagos, Segundo Manuel
In this research paper, a comparison was made between three types of bracing: in V, in Inverted V and in K of a 7-story building with the possibility of applying it in our environment as it is in the city of Ambato and also so that can be used at the national level since both national and American regulations were used. The pre-designs of the structural elements were made, both for the columns, main and secondary beams, collaborating plate, and the bracing elements to then carry out their respective design, first checking their compactness and slenderness in each of their elements. Through the use of finite element software, each of the structural elements was modeled, entering properties and specifications to its elements, a static and dynamic analysis was carried out, for which the load combinations were defined, and also the load spectrum. design, as well as the configurations of the structure in plan and elevation, in addition to the seismic zone according to the project that is being investigated, all this so that the 7-story structure is earthquake resistant and each of the checks stipulated by the Ecuadorian Construction Standard (NEC 2015). Comparisons were also made with the three different types of bracing and the price of the structure was analyzed. Finally, it was concluded that the best type of structure was the inverted V bracing, because it has a lower drift than the previous two with values less than two percent and has a good structural behavior compared to the other checks carried out as in the dynamic analysis that complies with a percentage greater than 80 percent, the rotational analysis less than 30 percent in both X and Y; and the participation of the mass greater than 90 percent.
Análisis y diseño estructural del edificio Mushuc Runa de diez pisos en estructura metálica, mediante comparación del análisis estático lineal, modal, estático no lineal (Pushover), dinámico no-lineal (historia de respuesta), y diseño estructural en concordancia con el AISC 341-16, AISC 358-16, e incidencia en las condiciones actuales de la edificación
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-08) Argüello Freire, César Hipólito; Guamanquispe Toasa, Jorge Patricio
The degree work in question consists of analyzing, through non-linear mathematical models, the seismic vulnerability of a building built in 2018 with structural steel (A572 GR 50) and a height of 9 floors with respect to the road. Likewise, the structural design carried out in 2017 (prior to construction), and compared with international standards, specifically those described in ANSI - AISC 341-16, 358s-16, 360-16, ASCE 41-13, FEMA 440, FEMA 273. The company AyF, Consultoría y Construcción provided all the necessary documents to carry out a correct seismic performance analysis; among the most important: mathematical model of analysis and structural design prepared in 2017, as-built plans prepared at the end of the work in 2018, ultrasound tests on welds, material quality certificates, architectural plans, among others. In this way and with all the documentation available, the expected results were obtained through nonlinear analysis (NSP) and (NDP), comparing maximum displacements, floor drifts, shear forces, formation of plastic hinges, failure, hysteresis diagrams and amount of energy dissipation; in this way, the level of seismic performance and the seismic vulnerabilityxviii of the structure were obtained for a design earthquake of 475 years of return period (earthquake considered due to the type of building) and it is expected that the civil works in question resist the design earthquake and is between the Operational – Functional states. Within the resilience rating with respect to FEMA P-58-1, the category that corresponds to the current system is "GOLD", where 10 percent damage and 4 weeks of occupation time are expected. Likewise, a comparison was made of the design carried out prior to construction (2017), with respect to the analysis carried out in this document; therefore, the dimensioning of cross sections used in the different structural members is justified. It should be noted that practical results have been obtained for the structural analysis specifically to the value related to the coefficient R (coefficient of seismic reduction) and that they can be extrapolated to different scenarios.
Análisis del comportamiento estructural mediante el uso de aisladores sísmicos y disipadores de energía en un edificio de estructura metálica, aplicando la norma NEC-15
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-08) Beltrán Vargas, Luis Miguel; López Arboleda, Gissela Vanessa; López Velástegui, Jorge Enrique
In this project there is the need of understanding the dynamical behavior of the building, so there are three structural models that are presented, the first model consisted in an analysis of a conventional building. In the second and third models, seismic isolators and energy dissipators were incorporated, respectively, taking into consideration the criteria of the Ecuadorian Construction Standard (NEC 15), American Society of Civil Engineers (ASCE 7-16, ASCE 41-13), American Institute of Steel Constructions (AISC 341-16). In the first stage of the analysis, the structure was analyzed and balanced, applying the recommendations of the NEC-15. Once the building was stabilized, the analysis of the conventional structure was carried out in order to determine floor drifts and displacements. Subsequently, the pre-dimensioning and corresponding design of the base seismic isolators was carried out, which were considered as elastomeric type devices with a lead core. In the third model, the design of the energy dissipators was carried out. With the necessary information, the values were entered into the calculation program to carry out the study of the structuralxv models. Once the structural model was generated in the software, data from the accelerograms were entered in order to perform a nonlinear dynamic time-history analysis, and a complementary nonlinear static analysis was performed. With the information entered in the software, the results for the first structural model were obtained, among the main results obtained from the structural package are: the floor drifts, displacements, displacement diagrams, energy balance diagrams, results of lateral loads, among others. In the same way, those analyses were developed in the structural models with the base isolation and energy dissipation devices, which, once the required results were obtained, a comparative analysis of the structural behavior was carried out, taking as main parameters of consideration the floor drifts, displacements obtained and energy balances.
Análisis dinámico no lineal de un puente colgante vehicular tipo de 100 metros de longitud ante cargas sísmicas y de viento, según AASHTO LRFD 2017 y NEC 2015
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Núñez Meneses, Jorge Luis; Medina Robalino, Wilson Santiago
The design of bridges is an area little shared in the third level of higher education, much less if they have special characteristics and large spans, such as suspension bridges. The present work contemplates the design of a 100-meter long suspension bridge, performing a linear and nonlinear analysis of wind and seismic loads, as well as assembling a document of manual calculations for the design of all the elements of the bridge, which can serve as a guide for professionals interested in this branch of engineering. As a first part, the analysis and design of the bridge super structure was carried out by means of dynamic analysis by vehicular loads, including, on the one hand, the wind load calculation method established in the AASHTO LRFD and NEC 2015 and, on the other hand, a wind tunnel. With a speed pattern equal to 80 mph (according to AASHTO LRFD), it was evidenced that the dynamic analysis by means of a wind tunnel is predominant with respect to the static analysis based on forces, since it shows in a real way the effects of the loads on each of the elements managing to obtain unfavorable situations, since, in general terms there are values of displacements higher by 10 percent. After the design of the superstructure, the analysis of the substructure under seismic loads was carried out, performing a spectral modal analysis vs. a nonlinear analysis in the time domain, using acceleration records of real earthquakes scaled to the design target spectrum, where the large differences between the demands produced in such analysis can be evidenced, although both methods are dynamic, it will always be advisable to perform it in the nonlinear range, since the real behavior of the seismic event is evidenced, besides allowing us to know the behavior and the variation of stresses and deformations during the duration of the seismic event. The nonlinear analysis in the time domain was performed based on 9 accelerograms that were scaled appropriately to the calculated target spectrum, whose results were unfavorable compared to the spectral modal analysis, since the calculated drifts are 74 percent higher in the Y direction; 10 percent higher in the X direction. Finally, a manual-type document with the design of the bridge elements according to AASHTO LRFD is presented.
Estudio comparativo entre las juntas de conexión empernadas y por soldadura en el área de acceso vehicular y entre piso de la edificación del parqueadero ubicado en la av. 12 de Noviembre de la ciudad de Ambato y su incidencia en el comportamiento mecánico operacional
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Zavala Córdova, Luis Eduardo; Ureña Aguirre, Maritza Elizabeth
This degree work is based on a building that was built in the city of Ambato in order to determine what would be the optimum behavior to the requirements established by the structural design standards, for which we proceeded to perform a quantitative analysis in the collection and analysis of results in the comparison of the joints that are currently built by welding, to perform the analysis by connections of RBS and BFP joints, taking into account the criteria of the Ecuadorian Construction Standard (NEC-15), Load and Resistance Factor Design (LRFD) and American Institute of Steel Construction (AISC 360-16), this analysis contributes to the modeling of bolted and welded connections, in order to analyze the localized buckling phenomenon in the wings and web of the metal profiles of the beam-column joint in the vehicular access area and the joint between floors, The results obtained showed that the RBS connection has a better deformation behavior without affecting the web and flanges of the profile, and that the BFP connection cannot be used in the same way as the BFP connection, the BFP connection cannot be used in joints where the inclination of the beam towards the column has a steep slope because the plates must be connected perpendicularly and the welding connection tends to be the most economical and can be used in any area, however it tends to reach the equivalent stressstrain deformation limit, in relation to the cost of materials used for the installation of the BFP joint it is more expensive because it implies placing more supply of elements in the joint.
Evaluación de edificios de mediana altura en estructura de acero con diagonales excéntricas, concéntricas
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Abril Gavilanes, Bernarda Estefanía; Guerra Avendaño, Oswaldo Marcelo
The purpose of this research project is to use stiffening systems that allow for better structural performance in the presence of seismic events by comparing structural energy dissipation systems such as: buildings with concentric diagonals in the form of x and buildings with eccentric diagonals with a link length of 1 meter in medium-rise steel buildings considering the mechanical and physical properties of these elements as well as the implementation and construction advantages. In this project, two 20-story steel buildings were compared, which have seismic stiffening systems that were located symmetrically in the structure, for modeling the ETABS 2016 software was used, applying the Ecuadorian Construction Standard (NEC-15). ), as well as the verification of compliance with the AISC 341-16 standard, from which an optimal seismic-resistant structural design was obtained that is within the permitted parameters. The use of concentric and eccentric diagonals allows to guarantee the stability in the structure, to obtain an appropriate structural behavior that allows to be able to minimize the horizontal movements caused by the earthquakes and the wind, it requires a greater rigidity and stability to the structure. The result was obtained by using concentric diagonals a vibration period of 2.037 seconds, the inelastic floor drift was 0.0129 mm, likewise the value of static and dynamic shear were 580.78 and 464.62 respectively, while when using eccentric diagonals the period of vibration was 1.921 seconds, with inelastic floor deviations of 0.0118 mm, complying with the requirements established by the NEC-15 norm, in the same way a static shear of 615.868 and a dynamic shear of 492.695. Additionally, a non-linear static analysis (Pushover) was carried out, where a load pattern was applied to all the nodes that join the main beams and columns, which is related to the modal shapes of the first two vibration modes of the steel structure. of medium height, where from the static capacity curve it was possible to observe that in the two models used concentric diagonals as well as eccentric diagonals the result is similar in terms of resistance drops, however compared to the concentric system, the system of Eccentric diagonals have higher ductility.
Desempeño de estructura metálica mediante análisis dinámico con acelerogramas ajustados con espectro medio condicional (CMS)
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Pérez Galarza, Christian Danilo; Chérrez Gavilanes, Diego Sebastián
The present investigation is carried out in Huachi Loreto in Ambato city, starting as a first point, to identify the geological faults near this study site that can contribute to generate a seismic event that affects the structures in the area. Using empirical formulas, the value of the shear wave velocity was obtained based on calculated values, specific to the site, such as the length of the fault, source - study distance, focal depth, expected moment magnitude, and values of the number of blows of the SPT test performed in situ. This shear wave velocity allows determining the type of soil existing in the area according to the ranges established by the Ecuadorian Construction Standard (NEC 2015). Subsequently, an attenuation model was chosen (Montalva) that allows to determine, by applying certain equations called GMPEs (ground motion prediction equations), a possible behavior of the soil based on complementary data to those already mentioned specific to the site such as distance and hypocentral depth. From the GMPE graph and the uniform hazard spectrum (UHS) and applying certain equations determined in the Bakker model, the conditional mean spectrum (CMS) was obtained. The use of this spectrum allowed a comparison of the behavior of a metallic structure proposed in this study, with respect to the elastic spectrum imposed by the NEC. This comparison was made on the basis of the results provided by the nonlinear dynamic analysis (time-history), through which the performance of the same structure subjected to scaled seismic events was determined with respect to the CMS and the NEC spectrum. It was obtained as a result that the seismic demand produced by the NEC spectrum is greater than that produced by the CMS, since the pseudospectral accelerations have a great difference between these spectra, which is why the maximum displacements and drifts are reduced by approximately 65 percent by applying the CMS in the present investigation.
Vulnerabilidad sísmica del parqueadero municipal del Gobierno Autónomo Descentralizado de Ambato, ubicado en la calle Cuenca y Montalvo
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Lucio Álvarez, Diego Ricardo; Peñafiel Valla, Lourdes Gabriela
Ecuador is located in the ring of fire, so different earthquakes at various levels are very common, the structures must be designed to withstand an earthquake of a rare level, the constructions must be ductile; the ductility is the time that the occupants of the structures have to be able to go out to a safe place, the secondary waves of the earthquakes are the ones that knock down the buildings, through the present study a building located in the central area of Ambato was taken as a sample , this structure should be in a life safety acceptance criteria, to start the present study the forms established by FEMA 154 and NEC 2015 were used and a visual inspection of the structure was carried out to know the irregularities in plan and elevation, In addition to knowing pathologies that the structure has, the main pathology is the short column, the parameters of the forms were established and it was concluded that it has a medium seismic vulnerability, with this information a nonlinear static analysis was carried out, it was necessary to use a computer program such as Etabs19, where the steel area was placed in each of the beams and columns, with this information formation we obtainedxxiv the plastic hinges, as well as the performance point and the capacity of the building under study, in which it was observed that the structure does not meet this acceptance criterion for the design earthquake, which is why it is necessary to carry out a reinforcement in beams, but above all in C2 columns, which are the columns that act the most in these two buildings. There are several methodologies for reinforcing structures among the most common (reinforcement with carbon fiber, reinforcement with screeding of structural elements and reinforcement with steel), reinforcement with angles and plates of A36 steel was chosen, these angles fastened with plates and bolts they help to gain ductility and more shear strength of the structure in order to meet the acceptance criteria for this type of building, which is life safety.
Análisis técnico económico del coeficiente de reducción de respuesta estructural con aplicación y comparación en sistemas aporticados de estructuras metálicas
(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Jácome Guanopatín, Ángel Patricio; Cañizares Ortega, Freddy Fernando
In this degree work, the analysis and calculation of the seismic reduction factor for a structure with special moment frames (PEM or SMF) composed of four different mathematical models where the seismic reduction factor changes with values of R=8, 6, 4, 5 and 3. 5 and 3; performing the dynamic linear structural analysis of the four models, each structure changes according to the demand required by the seismic forces, determining that the lower the value of R the larger sections are required in the structure, in spite of the above, the fundamental vibration period of the structures was maintained for R= 8, 6 and 4. 5, while for the factor R=3 the period is slightly reduced resulting in a stiffer structure, as the seismic response factor is reduced, more robust sections are required to provide more weight to the structure to meet the demand. An economic analysis was performed with the sections obtained, which shows that the lower the R value, the structure requires a higher weight and therefore influences a higher cost, so the structure with the lowest cost is the structure with an R=8. Additionally, a pseudo-static non-linear analysis was determined to determine the structural performance of each of the four models using the ATC-40 and FEMA- 440 methods, highlighting that the models maintain the same architectural and geometric configuration but with different sections in certain elements that required a higher geometry as the R value decreases, after obtaining the results of the static non-linear analysis, the performance point was determined using the ASCE 41-17 and FEMA 440 (2005) methodology, resulting in the R=8, 6, 4. 5 and 3 for 475 years has a performance level in X and Y of immediate occupancy. For the determination of the structural response factor, the methodology proposed by Dr. Aguiar 2006 was followed, which is similar to that of ATC-19 (1995), where the ductility, resistance and redundancy factor is determined, data that are collected from the performance point obtained for the elastic design spectrum with a return period of 475 years, the structural response factors R obtained establish that the average range is between 6 and 7.5, on the other hand the structure that presents greater capacity and performance is the one that was designed with R=4. 5 so having extremely rigid sections does not guarantee stability and ductility in a structure, finally a high level of performance (immediate occupation) and seismic energy dissipation capacity is established in the structure designed with a R=6 where its value is similar and slightly lower than 4.5, so it is concluded that for a structure of special steel composite moment frames a design with a structural response factor equal to 6 should be sought.