AM - Grupo de Investigación en Estructuras y Materiales

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Clasificación: A - Convocatoria 2018.

Conceptos básicos y principales metodologías del diseño estructural para condiciones de incendio según normas internacionales, aplicadas al Reglamento Colombiano de Construcciones Sismorresistentes (NSR-10)

Torres Zafra, Fabián | 2018

Entre los principales cambios que trajo la aplicación del reglamento NSR-10, se encuentra el incremento en la seguridad estructural que se les debe proporcionar a las edificaciones, la cual debería preverse desde el mismo inicio de los diseños tanto arquitectónicos como estructura-les, para luego aplicarla en la construcción de éstas. Los cambios más notables que trajo la aplicación del reglamento NSR-10 se plasmaron en los títulos F (estructuras metálicas) y J (requisitos de protección contra incendios en edificaciones), en lo referente al diseño estructural para condiciones de fuego, tema integrado en especial para estructuras de acero (dada su vulnerabilidad ante esta acción). En la práctica del diseño estructural en Colombia, este diseño es novedoso, pues su fi-nalidad radica básicamente en que la estructura no puede ser causante de pérdidas de vidas humanas al colapsar ante la acción del fuego.En el presente artículo se pretende compilar los principales conceptos y premisas del diseño estructural para condiciones de incendio en Colombia (plasmados en la NSR-10), con base en las normas interna-cionales, y definiendo las metodologías de análisis del diseño estructural más usadas actualmente.

Evaluación de la resistencia a compresión en morteros de cal, sometidos a diferentes condiciones de curado

Espitia Morales, Andrés Felipe | 2019

En este artículo se presenta la evaluación de la resistencia a compresión en morteros de cal, sometidos a diferentes condiciones de curado y diferentes edades de ensayo. En total, se evaluaron las propiedades mecánicas sobre tres tipos de morteros: uno con cal, y los restantes adicionados con puzolanas como metacaolín y polvo de ladrillo. Adicio-nalmente, en cada uno de los componentes de los morteros se evaluó la composición química mediante el ensayo de fluorescencia de rayos X. La resistencia a compresión se evaluó a cuatro edades, utilizando tres ambientes de curado: cámara de humedad y temperatura, cámara de carbonatación acelerada y condiciones atmosféricas. Los resulta-dos mostraron que las muestras curadas en cámara de carbonatación presentaron resistencias superiores a las de los especímenes curados en cámara de humedad, debido a que los morteros de cal aumentan su resistencia con la carbonatación del Ca(OH)2 de la cal. Así mismo, se encontró que la resistencia de las probetas expuestas a condiciones atmosféricas resultó inferior a las curadas con las otras metodologías. A partir de la investigación, se destaca que el uso de puzolanas en morteros de cal mejora las propiedades mecánicas, lo cual resulta atractivo para la rehabilitación de edificaciones patrimoniales y que el tipo de curado se encuentra ligado al desarrollo de la resistencia.

Explosions and Structural Fragments as Industrial Hazard: Domino Effect and Risks

Ahmed, Mebarki | 2012

This study deals with industrial accidents and domino effects that may occur in an industrial plant, the initial accident being supposed to take place in any of the tanks either under or at atmospheric pressure. This initial sequence might generate sets of structural fragments, fire balls, blast waves as well as critical losses of containment (liquid and gas) that threaten the surrounding facilities and may cause serious damages. The structural fragments, the blast wave and the fire ball can be described following database and feedback collected from past accidents. The vulnerability of the potential targeted tanks is investigated in order to assess the risk of propagation of the first sequence of industrial hazard. Cascading sequences of accidents, explosions and fires can take place, giving rise to the domino effect. This risk of domino effect occurrence is investigated herein. The interaction and the behavior of the targets affected or impacted by the first explosion effects are described by adequate simplified mechanical models: perforation and penetration of metal fragments when they impact surrounding tanks, as well as global failure such as overturning, buckling, excessive bending or shear effects, etc. Sensitivity analysis is performed thanks to Monte Carlo simulations: the probability of impact and risk of failure of target tanks are reported. A comparison between risks due to blast wave and fragments impacts is performed.

Rigidez de una conexión de columna-cimentación para estructuras de Guadua angustifolia Kunth

Lamus Báez, Fabián Augusto | 2014

Una de las limitantes que encuentran los ingenieros estructurales para el diseño de una edificación y, en general, de cualquier estructura en Guadua angustifolia Kunth es la falta de información técnica relacionada con los parámetros necesarios para realizar un adecuado modelo numérico de esta. El grado de empotramiento que puede brindar un apoyo al elemento estructural que soporta es una variable importante durante la modelación estructural, debido a que el criterio del ingeniero en la selección de este parámetro para la modelación puede incidir en la rigidez de la estructura y, por tanto, en su periodo de vibración. En este artículo se presentan los resultados experimentales de la constante de rigidez de una conexión entre una columna de Guadua angustifolia Kunth y un elemento de concreto que forma parte de la fundación, cuando la columna está solicitada a cargas laterales monotónicas. Adicionalmente, se ha evaluado la incidencia de cada uno de los componentes de la conexión en la rigidez de la estructura.

Vulnerability and Resilience under Effects of Tsunamis: Case of Industrial Plants

Mebarki, Ahmed | 2014

The resilience approach represents a unified and integrated framework for the restoration process following disasters. Under given resilience parameters values, a resilient system is able to recover and be strengthened within a defined recovery period; otherwise, it is a non-resilient system. This paper considers different structures and focuses on several parameters which govern resilience together with their mechanical vulnerability under various hazards. A new method of theoretically measuring resilience, its link with mechanical vulnerability and its sensitivity analysis are investigated for industrial plants under the effects of flood and tsunami hazards: -Coastal industrial plants under the effects of a tsunami hazard: structural failure in tanks results from buoyancy (uplift), overturning, sliding by shear effect, excessive bending, or buckling. -Vulnerability and fragility curves are developed for various tanks of small and large sizes.

Los puentes metálicos: su historia y la experiencia colombiana

Uribe Escamilla, Jairo | 1996

Modelos estructurales: Gran incentivo para aprender el comportamiento estructural

Uribe Escamilla, Jairo | 2005

Aciem frente a los exámenes de calidad de la Educación Superior - ECAES de Ingeniería. Algunos modelos de flexibilidad curricular en América Latina. Apertura de Ingeniería Química en la Universidad de Cartagena: innovación en flexibilidad e integralidad curricular. Atomatización y mecatrónica en la educación. Bodegas de datos: instrumento fundamental para la autoevaluación con miras a la acreditación. Competencias en emprendimiento y liderazgo: necesidad o mito en la formación del ingeniero. De lo abstracto de un modelo curricular a lo práctico de un plan de estudios. Determinación de competencias profesionales en diez especialidades de la ingeniería. Diseño curricular en la formación de tecnólogos e ingeneiros bajo la modalidad de ciclos propedéuticos. Efectos de la acreditación en las instituciones y programas de ingeniería en Colombia. El espacio Europeo de Educación Superior y su incidencia en la Educación Superior en Colombia (Programas de Ingenierías). El ingeniero general que Colombia requiere en el marco de la formación por competencias. Elaboración de un currículo basado en competencias. Evaluación de programas de las asignaturas: antesala del logro de la acreditación y calidad educativa. Formación doctoral colombiana en ingeniería vs grupos de investigación y programas nacionales de ciencia y tecnología. Formación y desempeño: retos para el curriculo en ingeniería. ¿Formar ingenieros o tecnólogos?. Identificación de competencias genéricas para profesionales de la ingeniería. La pedagogía del aprendizaje de las ciencias en el ciclo básico de ingeniería. Logística de conocimiento para la gestión de registro calificado. Los ECAES como generadores de dinámicas académicas. Modelo sistémico para la formación de un ingeniero clase mundial en Colombia. Planteamientos generales para el diseño de una propuesta curricular por ciclos propedéuticos. Sistemas y auditorias de calidad en la educación

Domino Effects and Industrial Risks: Integrated Probabilistic Framework – Case of Tsunamis Effects

Mebarki, Ahmed | 2013

This paper presents an integrated probabilistic framework that deals with the industrial accidents and domino effects that may occur in an industrial plant. The particular case of tsunamis is detailed in the present paper: simplified models for the inundations depths and run-ups as well as their mechanical effects on industrial tanks. The initial accident may be caused by severe service conditions in any of the tanks either under or at atmospheric pressure, or triggered by a natural hazard such as earthquake, tsunami or extreme floods for instance. This initial event generates, in general, a set of structural fragments, a fire ball, a blast wave as well as critical losses of containment (liquid and gas release and loss). The surrounding facilities may suffer serious damages and may also be a new source of accident and explosion generating afterwards a new sequence of structural fragments, fire ball, blast wave and confinement loss. The structural fragments, the blast wave form and the features of the fire ball can be described following database and feedback collected from past accidents. The surrounding tanks might be under or at atmospheric pressure, and might be buried or not, or protected by physical barriers such as walls. The vulnerability of the potential targets should therefore be investigated in order to assess the risk of propagation of the accidents since cascading sequences of accidents, explosions and fires may take place within the industrial plant, giving rise to the domino effect that threatens any industrial plant. The present research describes the risk of domino effect occurrence. The methodology is developed so that it can be operational and valid for any industrial site. It is supposed to be valid for a set of sizes, forms and kinds of tanks as well as a given geometric disposal on the industrial site. The interaction and the behavior of the targets affected or impacted by the first explosion effects should be described thanks to adequate simplified or sophisticated mechanical models: perforation and penetration of metal fragments when they impact surrounding tanks, as well as global failure such as overturning, buckling, excessive bending or shear effects, etc. The vulnerability analysis is detailed for the case of tanks under the mechanical effects generated by tsunamis.

Evaluation of the Permeation Properties of Concrete Added with a Petrochemical Industry Waste

Torres Castellanos, Nancy | 2015

In this work, the evaluation of the performance of concrete added with a petrochemical industry waste called Fluid Catalytic Cracking Catalyst residue (FCC) from a Colombian petroleum company is presented. Results of this concrete are compared, with the results of concrete added with a pozzolan with similar characteristics such as the Metakaolin (MK). The analysis of the pozzolanic materials included the determination of the particle size, the pozzolanic activity, and the chemical and mineralogical composition. Different percentages of FCC were used as Portland cement replacement in proportions of 0, 10, 20 and 30 %; similarly concrete added with 20 % of MK as replacement was elaborated. The curing time was 28, 56, 90 and 180 days. These concretes were evaluated through the permeation properties such as: total absorption, porosity, surface absorption and capillary absorption. Results showed that concrete with FCC and MK had similar behavior, and slightly superior than the control sample. The total absorption and porosity were less than 3 % and 10 % respectively for the all of the samples; it means that these concretes had good quality and compactness. The results of surface absorption and capillary absorption showed that these concretes had low permeability too. This behavior is enhanced with the curing age.

Connection between a Column and its Foundation for Guadua Angustifolia Structures under Lateral Loads

Andrade Pardo, Sofía | 2015

In Colombia, as in other developing regions, social housing shortage related problems has led local authorities to propose low cost housing projects that allow its quickly and easy construction. Among the requirements of this type of construction are solicitations for vertical and lateral loads caused by wind or earthquake forces, as well as the sustainable use of natural resources Considering this, the use of Guadua angustifolia Kunth (Guadua a.) as a structural material has awaken a great interest, considering its renewability, high-speed growth, ecological benefits and because is easily obtainable all across the country. Due to the lack of additional information, structural joints in this type of materials, are usually pinned, assuming that there is no moment transmission between the different elements, however, some types of connections can partially restrict the rotation in the supports. Additionally, the degree of constrain that any support can provide to the column is a variable that has not been studied enough, despite being essential for modeling and structural design.In this work a connection between a column of Guadua a. and its foundation was studied. The influence of each component on the connection behavior under horizontal loads was assessed, testing seven different configurations. Monotonic and dynamic testing of connections as well as the characterization of the materials used in its construction were included in the experimental schedule. It was determined that the presence of mortar grouting together with the use of longitudinal bolts slightly increases the connection strength as drastically reduce its ductility. The use of transversal bolts is the best alternative to obtain a strong, stiff and ductile connection, especially when are combined with the use of hoops.

Educación e investigación en Colombia de arquitectura en tierra

Ruiz Valencia, Daniel Mauricio | 2016

CDW Integrated Management, from Linear to Circular Economy in Bogota

Rodríguez Bello, Luz Angélica | 2019

Construction and demolition waste (CDW) has become an environmental, social and economic problem in some regions. Many initiatives to increase CDW recycling and concrete with recycled aggregates have failed or have not accomplished the goals, due to the lack of good management. In Bogotá, even though regulations establish that 25% must be harnessed, only 17% is achieved. To obtain rates as high as the global ones, a CDW diagnosis in works is run and policy instruments that would allow the application of a circular economy concept as opposed to a linear economy are determined. It is found that economic and informative instruments are the most popular worldwide and the most requested at the national level, in comparison to regulatory instruments which currently prevail in Bogotá. Likewise, the literature highlights prevention actions and the national context prefers recycling and disposition actions.

Assessment of Anchorage Methods and FRP Laminate Strengthening Configurations for URM Walls Under In-Plane Loading

Torres Castellanos, Nancy | 2018

In order to ensure a continuous and reliable path for the lateral loads caused by earthquake or wind forces, FRP-strengthened masonry walls that are part of the lateral load resisting system of a building require the joint work of the FRP strengthening to resist tensile stresses in the masonry and anchorage to the boundary structural elements (foundations or beams) to transfer the loads. This article presents the results of an investigation on the assessment of anchorage methods and FRP strengthening configurations for unreinforced masonry (URM) walls subjected to in-plane loads. Fourteen masonry walls were constructed for this experimental program. All of the walls were built with hollow clay bricks, typical of URM structures in Colombia and other parts of the world. The specimens for this investigation included slender and squat walls. The dimensions of the slender walls were 1.20 m. [4 ft] long, 1.90 m. [6.2 ft.] high, and 120 mm [4.8 in.] thick. The dimensions of the squat walls: 2.50 m. [8.2 ft.] long, 1.90 m. [6.2 ft.] high, and 120 mm [4.8 in.] thick. The walls were strengthened using two configurations: (1) Layout ‘H’ involving horizontal CFRP laminates along on wall side, and vertical CFRP laminates at each wall toe on one side of the wall, and (20 Layout ‘X’ involving diagonal CFRP laminates oriented at approximately 45 degrees on one side of the wall. Four anchor systems were evaluated: (1) System 1 (CFRP anchors embedded in the base beam), (2) System 2 (CFRP bonded to the base beam), (3) System 3 (FRP bonded to grout blocks), and (4) System 4 (FRP wrapped around grout blocks). The walls were tested in two series: (1) Series 1 – Monotonic Loading, and (2) Series 2 – Cyclic Loading. The test results demonstrated that Anchor System 4 was the most effective anchorage system. The walls strengthened with Anchor System 4 failed due to rupture of the CFRP laminates wrapped around the grout block. In general, the largest increases in in-plane capacity, when compared to the control walls, were observed in the slender walls. The walls with the ‘H’ Layout showed more ductility and less degradation of the lateral stiffness than the walls strengthened with the ‘X’ Layout.

Masonry Walls Reinforced with FRP Bars Subjected to Out-of-Plane Loading

Tumialan, Gustavo | 2018

This article presents the results of a research program on the behavior of masonry walls reinforced with FRP bars subjected to out-of-plane loads. The article also proposes a preliminary protocol for the flexural design of masonry walls reinforced with FRP bars. The objectives of this investigation were: (1) evaluate the flexural behavior of masonry walls reinforced with FRP bars subjected to out-of-plane loads, and (2) develop preliminary design recommendations. Ten masonry walls, 2 m [6.6 ft] high, were subjected to out-of-plane loads, tested under quasi-static loading cycles. The test specimens included walls constructed using concrete and clay masonry units, reinforced with Glass FRP (GFRP) and Carbon FRP (CFRP) bars in different configurations. All the FRPreinforced masonry walls showed a bilinear moment-deflection curve with one steep slope up to cracking of masonry and a decrease in stiffness after cracking. The majority of the walls failed due to crushing of masonry in the compression side. After failure occurred and as the out-of-plane load was progressively removed, the walls returned to a position close to the initial vertical position. In general, the approaches used to calculate flexural strengths and deflections provided good agreement with the experimental results.

Development of cost-efficient UHPC with local materials in Colombia

Abellán García, Joaquín | 2020

Ultra-high-performance concrete (UHPC) is an essential innovation in concrete research of recent decades. However, because of the high contents of cement and silica fume used, the cost and environmental impact of UHPC is considerably higher than conventional concrete. The use of industrial by-products as supplementary cementitious materials, in the case of recycled glass powder and fluid catalytic cracking catalyst residue (FCC), electric arc slag furnace (EASF), fly ash (FA), ground granulated blast slag furnace (GGBSF), rice husk ash (RHA) as partial substitution of cement and silica fume allows to create a more ecological and cost-efficient UHPC. Moreover, other products like limestone powder could be added to the mixture to reduce the final cost of UHPC and improve its rheology. For the 22 UHPC families with different binder composition tested, the design of the concrete mixtures was based on the goal of achieving mechanical and rheological properties with minimum amounts of cement, and a maximum amount of silica fume of 100 kg/m3, through a 3-factor Design of Experiments (DoE). The factors considered in this research were cement content in kg/m3 (factor A), water to binder ratio (factor B), and volume of superplasticizer (Factor C). Statistical tools such as Pareto plots, Principal Effect Plot, Stepwise Backward, Quadratic-order Regression, and Response Surface Methodology (RSM) were used to find the models for mechanical and rheological properties which included compressive strength at 1, 7, and 28-day, slump flow. Models for 28-day compressive strength and slump flow were the starting point for multi-objective optimization. The use of 590 kg/m3 of ASTM Type III cement, blended with micro limestone powder and recycled glass flour should be considered the most appropriate dosage to be employed in UHPC mixtures to reach a 28-day compressive strength over 150 MPa with a proper spread flow.

Machine Learning Prediction of Flexural Behavior of UHPFRC

Abellán García, Joaquín | 2020

To evaluate the possibility of predicting the flexural behaviour of UHPFRC, four analytical models were developed, based on artificial neural networks (ANN), to predict the first cracking tension or Limit of Proportionality (LOP), its corresponding deflection (δLOP), ultimate strength or Modulus of Rupture (MOR), and its corresponding deflection (δMOR) of UHPFRC under bending test. The models that were composed of an input level, one output level, and four hidden levels were developed through the R platform. The input level applied the most significative Principal Components (PC) of a large dimension of input dataset. To avoid overfitting K-fold validation and l2 regularization was used. After the models were created, an improvement based on assembling of models by incorporating the predicted values in the dataset of features. The results indicated that the developed assembling models have a good accuracy for the prediction of the behaviour of UHPFRC under three or four points bending test, even when containing supplementary cementitious materials and hybrid mixture of fibers.

Análisis de estructuras

Uribe Escamilla, Jairo | 1991

Microcomputadores en ingeniería estructural

Uribe Escamilla, Jairo | 1995

El impresionante desarrollo de las computadoras personales ha causado un impacto profundo en los procedimientos de análisis y diseños de estructuras. Si bien esto ha facilitado enormemente su cálculo mediante el uso de programas comerciales muy poderosos, se corre el riesgo de que los utilicen ingenieros sin la experiencia suficiente que les permita detectar posibles errores en los resultados. Ello se debe, en su mayoría, al aplicar equivocadamente el modelo matemático utilizado en dichos programas a estructuras que no cumplen los supuestos involucrados. Es por eso que los códigos de diseño de la mayoría de lo países exigen como lo hace en Colombia la norma AIS 100-95, que cuando se utilicen procedimientos de cálculo electrónico sea obligación del ingeniero conocer a fondo los fundamentos bajo los cuales se desarrollaron los programas utilizados y las suposiciones que el programa utiliza internamente, con sus correspondientes limitaciones. Microcomputadoras en ingeniería estructural fue escrito con ese propósito.

Análisis de estructuras

Uribe Escamilla, Jairo | 2000

Esta es la segunda edición revisada y actualizada de esta magnífica obra que trata los fundamentos de la teoría de estructuras y los métodos tradicionales para el análisis de todo tipo de estructuras reticulares, y el aprendizaje de las técnicas de análisis tradicionales y modernas. Hace énfasis en los conceptos fundamentales de la ingeniería estructural y en el estudio de los métodos más adecuados para cada tipo de problema. Gran parte del libro está dedicada al análisis matricial, que constituye la herramienta más apropiada para el análisis de estructuras utilizando computadores.

Natural hazards, vulnerability and structural resilience: tsunamis and industrial tanks

Mebarkia, Ahmed | 2016

The paper presents an integrated framework which deals with natural hazards (tsunamis), physical vulnerability modelling, risk of failure for industrial structures (metal structures) and structural resilience provided by plastic adaptation. Simplified models are proposed to describe the run-up and wave height attenuation in case of tsunamis. The results are calibrated in the case of important tsunamis having taken place in Asian region. The mechanical vulnerability of cylindrical metal tanks erected near the shoreline is also investigated. The fragility curves are then developed in order to describe the multimodal failure: overturning, rupture of anchorages and sliding, buoyancy, excessive bending effects or buckling. Corresponding fragility curves are developed under various conditions: height of tsunami waves, filling ratios and service conditions of the tanks, friction tank/ground as well as dimensions effects. Probabilistic description of the natural hazard and the fragility curves are presented. Sensitivity analysis is also performed in order to investigate the effect of various governing parameters. Furthermore, resilience concepts and metrics are proposed. Theoretical description of the damages and post-disaster recovery functions are discussed: plastic adaptation as well as elastic and plastic attractors.