A otimizacao combinatoria e comumente utilizada na resolucao de aplicacoes reais complexas, onde ... more A otimizacao combinatoria e comumente utilizada na resolucao de aplicacoes reais complexas, onde geralmente a solucao pertence a um conjunto discreto, resultante de todas as combinacoes possiveis. Um problema desta natureza e o de alocacao de salas de aula em instituicoes de ensino onde, na distribuicao das salas de aula disponiveis, devem ser respeitados tanto o numero de alunos de cada disciplina/turma, como as capacidades das salas. Assim, neste trabalho apresenta-se uma formulacao desenvolvida para a otimizacao do problema de alocacao de salas na Universidade de Passo Fundo. Ao se buscar a solucao automatizada para este problema, foi elaborado um modelo de otimizacao, no qual objetiva-se minimizar a distância total percorrida pelos alunos, com intuito de realizar a distribuicao das salas de aula, dos diversos predios, de modo a manter os alunos o mais proximo possivel das suas respectivas unidades. O processo de otimizacao foi realizado atraves do metodo Simulated Annealing, uma...
Em funcao da grande diversidade de configuracoes possiveis, seja para superar um determinado vao,... more Em funcao da grande diversidade de configuracoes possiveis, seja para superar um determinado vao, seja para resistir a um determinado carregamento, as trelicas constituem um campo bastante fertil ao emprego de tecnicas de otimizacao. Com o emprego dessas tecnicas, busca- se quantificar o minimo de material necessario para que a estrutura suporte um determinado carregamento com a devida seguranca. Os problemas de otimizacao de trelicas sao classificados basicamente em tres categorias: otimizacao de secoes transversais, de geometria e de topologia. O presente trabalho apresenta um experimento desenvolvido na Universidade de Passo Fundo, atraves do qual objetivou-se a validacao de estudos numericos envolvendo a otimizacao de secao e de geometria de trelicas. Inicialmente, foram efetuadas diversas simulacoes com o emprego de um programa desenvolvido para a otimizacao de trelicas pelo Metodo do Recozimento Simulado (Simulated Annealing). Na sequencia, a partir dos resultados obtidos, for...
Apresentam-se resultados de uma investigacao qualitativa sobre influencias do uso tecnologias int... more Apresentam-se resultados de uma investigacao qualitativa sobre influencias do uso tecnologias interativas em sala de aula, referente a aprendizagem significativa de conceitos de Algebra Linear. Para tanto se propos o desenvolvimento e analise de dados sobre uma atividade de ensino que visou a aprendizagem significativa de sistemas lineares, propiciada pela resolucao de um problema contextualizado. A coleta de dados se deu por meio de observacoes ocorridas durante a aula, bem como por materiais escritos produzidos pelos estudantes. A analise dos dados indica que a atividade, realizada de forma colaborativa, em grupos, possibilitou por meio das reflexoes e discussoes, (re)significar conceitos sobre resolucao algebrica e sistemas de equacoes lineares. Ao perceberem seus usos na resolucao de um problema comum em suas areas de atuacoes profissionais, conseguiram relacionar conceitos das disciplinas de Estatica e de Algebra Linear. Alem disso, ao interagirem com o ambiente do software Geo...
Cold-formed profiles has been used in large scale in Building industry, due to the easy way to pr... more Cold-formed profiles has been used in large scale in Building industry, due to the easy way to product them and the wide range of sections feasible to accomplish with the project needs. The search for a maximum performance of structural elements with the low use of material is a challenge of today and future for engineering. This paper presents a numeric study to obtaining minimum weight of cold-formed channel columns, with and without lips, using the prescriptions of AISI 2007. Flexural, torsional and torsional–flexural buckling of columns was considered as constraints. The optimization was made through the method of Simulated Annealing. Several numeric simulations are presented and discussed to validate the proposal and an experimental example that qualifies the implementation. The relations between lips, web width and flange width are analyzed. Finally, the process shows excellent results to reduce the cross section area.
Dentre as diversas propostas pedagogicas, a aprendizagem por projetos tem adquirido crescente des... more Dentre as diversas propostas pedagogicas, a aprendizagem por projetos tem adquirido crescente destaque por proporcionar a construcao efetiva do conhecimento com a participacao ativa dos estudantes. Com a finalidade de consolidar o conhecimento adquirido na area de estruturas em cursos de engenharia civil, atividades envolvendo a construcao de estruturas em escala reduzida vem sendo cada vez mais empregadas. O presente trabalho relata uma atividade desenvolvida no Curso de Engenharia Civil da Universidade de Passo Fundo, caracterizada por uma peculiaridade em relacao a grande parte das atividades desse tipo: o desenvolvimento de um projeto experimental inicial, que possibilitou a elaboracao de etapas e de estabelecimento de criterios a serem utilizados nos desenvolvimentos de outros projetos semelhantes, realizado por colegas de curso. Ou seja, um grupo de alunos do Curso, constituido de bolsistas de iniciacao cientifica, foi incumbido de efetuar a proposta de uma atividade a ser des...
In order to support the structural designer with regard to the selection of structural materials,... more In order to support the structural designer with regard to the selection of structural materials, this work presents results obtained from the optimization of reinforced concrete beams and welded “I” steel beams. To achieve this objective, both problems were formulated according to Brazilian standards, considering the cost as objective function and section dimensions as design variables. For the optimization of the proposed problems, Simulated Annealing optimization algorithm was adopted. Beams were optimized considering spans from 1 up to 25 m and two different loads. To the structures analyzed, the final costs for steel beams have always been higher than reinforced concrete, but concrete beams are significantly heavier than steel beams.
Rosana Maria Luvezute Kripka Instituto de Ciências Exatas e Geociências, Universidade de Passo Fu... more Rosana Maria Luvezute Kripka Instituto de Ciências Exatas e Geociências, Universidade de Passo Fundo Brasil [email protected] Moacir Kripka Faculdade de Engenharia e Arquitetura, Universidade de Passo Fundo Brasil [email protected] Carlos Ariel Samudio Pérez Instituto de Ciências Exatas e Geociências, Universidade de Passo Fundo Brasil [email protected] Guilherme Fleith de Medeiros Faculdade de Engenharia e Arquitetura, Universidade de Passo Fundo Brasil [email protected]
The aim of this work is to present a procedure developed in order to minimize the cost of reinfor... more The aim of this work is to present a procedure developed in order to minimize the cost of reinforced concrete building frames. To achieve this objective the cross sections dimensions, the area of steel and the concrete strength of beams and columns were taken as design variables. The constraints related to dimensions and strength were based on the Brazilian standard ABNT NBR 6118 (2007). The total cost, composed by the costs of concrete, steel and formworks, was minimized by the usage of Harmony Search Algorithm (HS), an optimization method developed by Geem, Kim and Loganathan (2001), inspired by the observation that the aim of music is to search for a perfect state of harmony. The search process is compared to a musician’s improvisation process. Some structures were analyzed, and the results were compared to those obtained from the conventional design procedure, in an attempt to identify the influence of factors such as resistance class, material costs and beams/columns costs on t...
Competition among companies is growing globally, with the need to increase productivity and effic... more Competition among companies is growing globally, with the need to increase productivity and efficiency in the product sector. However, there is also a growing concern about global warming and the depletion of natural resources, as well as their effects on human health. In this context, all human activities that involve intense usage of resources must take into account sustainability as one of the decision criteria. This work presents the application of decision-making methods to define the best product mix in the agricultural machinery industry. With this objective, the current schedule of the production line was identified, along with the production flow, by performing an inventory analysis and an environmental impact study (endpoint). A total of seven alternatives for the production mix of grain trailers were defined, considering different materials and production processes. The selection of the best schedule according to the different criteria was performed through the analytic h...
Infrastructure is an indispensable and decisive requirement for the economic development of a cou... more Infrastructure is an indispensable and decisive requirement for the economic development of a country; it is directly linked to the set of structural economic activities and serves as the foundation for the development of other activities. In this context, the bridges have fundamental importance to the social and economical development of the cities, because the roads are to ensure the entry of inputs on farms, as well as the disposal of products and free movement of populations. The aim of this study is to present a survey of the existing bridges in the south region of Brazil, more specifically in the city of Pato Branco, identifying the most recurrent damages, in order to provide bases to administrators, with the intention of ensuring the correct functioning of the transport infrastructure and in the preservation of public property and security for the users. Data collection was conducted through visits, using the method of visual and photographic records. After the analysis was d...
Corresponding Author: Moacir Kripka Department of Civil Engineering, University of Passo Fundo, P... more Corresponding Author: Moacir Kripka Department of Civil Engineering, University of Passo Fundo, Passo Fundo, Brazil Email: [email protected] Abstract: The current scenario of structural engineering is guided by the growing ecological concern and constant search for efficient and economic structural solutions. In this sense, aspects related to the durability of structures have become a significant topic of study. Based on this context, the purpose of this work was to provide resources that allow the maximization of the useful life of reinforced concrete columns during the design phase. To achieve this objective, different scenarios were simulated for the properties of concrete and environmental properties and the corresponding transversal cross-sections were defined with the usage of an optimization method. The results obtained showed that the parameters that most interfere in the durability of the structure are the covering thickness and the compression strength. It was found that the ...
O objetivo do presente trabalho e estudar a importância da consideracao da sequencia de carregame... more O objetivo do presente trabalho e estudar a importância da consideracao da sequencia de carregamento e construcao, na analise de edificios, bem como as formas de melhor simular esta sequencia. Com esta finalidade foi desenvolvido um programa de computador, baseado no metodo dos deslocamentos, que efetua a analise tanto pelo procedimento convencional como pelo procedimento incremental construtivo. Este ultimo permite a obtencao nao apenas dos esforcos finais como tambem dos desenvolvidos durante uma determinada etapa de construcao, podendo-se reproduzir os efeitos do processo de escoramento e da construcao das alvenarias ou ainda efetuar a pesquisa dos esforcos extremos, entre outras facilidades. Atraves dos exemplos analisados foi possivel comprovar que o procedimento convencional de analise conduz a resultados pouco confiaveis, sendo portanto o procedimento incremental indispensavel para que se aproxime as reais condicoes a que as estruturas sao submetidas.
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica
When designing a building, the selection of the most appropriate structural material may be based... more When designing a building, the selection of the most appropriate structural material may be based on several factors such as cost, performance, availability, and, more recently, the possible environmental impacts produced. One way to select the best alternative based on several criteria may be the use of decision-making techniques. Multicriteria decision analysis standardizes the decision-making process through mathematical modeling, helping the decision maker to solve problems in which there are several objectives to be achieved simultaneously. Among the existing methods, one of the most widely used is the Analytic Hierarchy Process (AHP), which is based on the division of the decision problem into hierarchical levels and the paired comparison. The present work had as objective to present a methodology employed to compare three types of structural materials, concrete, steel and wood, according to both objective and subjective criteria. Among the results obtained, it was found that, despite the lower environmental impact attributed to the wood, as well as the better strength of steel, concrete was the material that presented the best total score, mainly due to its lower cost and to cultural aspects.
Journal of Construction Engineering, Management & Innovation
The application of optimization to the solution of practical structural engineering problems has ... more The application of optimization to the solution of practical structural engineering problems has been very limited, despite the great development of the techniques. One of the main reasons for this is the complexity of the generated models, which employ nonlinear functions and generate a space of nonconvex solutions. In addition, most design variables, as in the case of steel profiles, can only assume discrete values. Traditional methods of mathematical programming are very limited in solving problems with these characteristics, opening space to the usage of heuristic methods and, more specifically, to metaheuristic methods. The main advantage of this class of methods is the fact that they only involve values of the functions in the optimization process, regardless of the existence of unimodality or even continuity in the derivatives of the functions involved. The present work presents the application of a heuristic method, the simulated annealing method, to the optimization of steel trusses with parallel chords, also called flat trusses. Initially, several usual configurations of trusses were analyzed, aiming to identify which led to the lowest cost. The top chord coordinates were also included as design variables, with the purpose of verifying the relations between span and height normally indicated in the literature as the most economical. Among the results, it was verified that the inclusion of the height of the truss among the design variables can lead to a significant additional cost savings.
International Journal of Environmental Research and Public Health
The application of techniques to analyze sustainability in the life cycle of small-span bridge su... more The application of techniques to analyze sustainability in the life cycle of small-span bridge superstructures is presented in this work. The objective was to obtain environmental and economic indicators for integration into the decision-making process to minimize the environmental impact, reduce resource consumption and minimize life cycle costs. Twenty-seven configurations of small-span bridges (6 to 20 m) of the following types were analyzed: steel–concrete composite bridges, cast in situ reinforced concrete bridges, precast bridges and prestressed concrete bridges, comprising a total of 405 structures. Environmental impacts and costs were quantified via life cycle environmental assessment and life cycle cost analysis following the boundaries of systems from the extraction of materials to the end of bridge life (“from cradle to grave”). In general, the results indicated that the environmental performance of the bridges was significantly linked to the material selection and bridge...
Engineering, Construction and Architectural Management
PurposeThe fair wage potential (FWP) is a social assessment method that can serve as an important... more PurposeThe fair wage potential (FWP) is a social assessment method that can serve as an important measure to estimate the related social impacts along a product's life cycle; however, it does not admit a direct relation to the functional unit. This research presents the weighted fair wage potential (WFWP) method that relates the functional unit to the FWP. It is a simplified method to connect the material inventory to social data. This study aims to develop an approach to assess and choose the best construction typology for buildings based on the social sustainability of workers involved in the sectors.Design/methodology/approachThe study is presented in phases. Phase 1 selected and identified two Brazilian house projects, which were considered for the following processes: extraction of raw materials, manufacture of building materials and housing construction. Phase 2 assembled the social life cycle inventories and executed them using the social life cycle assessment (SLCA). The...
International Journal of Structural Glass and Advanced Materials Research
Concrete is one of most used materials in construction and also one of the main responsible for t... more Concrete is one of most used materials in construction and also one of the main responsible for the emission of carbon dioxide, or CO 2 , in the atmosphere. Thus, in order to study ways to reduce this impact, it is important to evaluate the influence of each raw material of the reinforced concrete, as well as the phases of the life cycle in which these impacts are more relevant. This paper presents a review of recent studies related to carbon dioxide emissions of the materials of reinforced concrete. In this review, we sought to identify the phases of the life cycle of reinforced concrete most focused by researches. It was found that the cement production stage is the most contemplated in the studies, many of them focusing on the additions of complementary cementitious products, since cement is among the materials that contributes decisively to the total CO 2 emissions. The structure sizing, with the definition of concrete strength to be adopted in the design, were also extensively investigated, since these are phases in which it is identified a greater possibility of contribution, by the researchers, for the minimization of the impacts.
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica
In a built environment, practice of sustainability is a responsibility of all involved in the des... more In a built environment, practice of sustainability is a responsibility of all involved in the design and execution. Most of the measures should be used in the design stage, in which there are the greatest implications regarding the dimensions, specifications and details incorporated into the structure. Therefore, prior identification and study of the impacts generated in the environment allow professional, company or public agencies to develop action plans and innovative solutions focused on reducing of negative impacts. This paper shows a literature review on the alternatives applicable in the project phase, in order to minimize the environmental impact of reinforced-concrete buildings. Initially, a brief history and a contextualization about sustainability has been presented. After, this work relates studies in civil engineering, with an emphasis on structural design. The proposed alternatives include the role of each professional in the project development, such as studies and applications on sustainable concrete, including the relationship between structural optimization and environmental impacts of reinforced-concrete buildings. Thus, it was possible to conclude that with these avaliable options, designer must verify which one will result better results with lower expenses and consumption of labor, financial and structural resources.
A otimizacao combinatoria e comumente utilizada na resolucao de aplicacoes reais complexas, onde ... more A otimizacao combinatoria e comumente utilizada na resolucao de aplicacoes reais complexas, onde geralmente a solucao pertence a um conjunto discreto, resultante de todas as combinacoes possiveis. Um problema desta natureza e o de alocacao de salas de aula em instituicoes de ensino onde, na distribuicao das salas de aula disponiveis, devem ser respeitados tanto o numero de alunos de cada disciplina/turma, como as capacidades das salas. Assim, neste trabalho apresenta-se uma formulacao desenvolvida para a otimizacao do problema de alocacao de salas na Universidade de Passo Fundo. Ao se buscar a solucao automatizada para este problema, foi elaborado um modelo de otimizacao, no qual objetiva-se minimizar a distância total percorrida pelos alunos, com intuito de realizar a distribuicao das salas de aula, dos diversos predios, de modo a manter os alunos o mais proximo possivel das suas respectivas unidades. O processo de otimizacao foi realizado atraves do metodo Simulated Annealing, uma...
Em funcao da grande diversidade de configuracoes possiveis, seja para superar um determinado vao,... more Em funcao da grande diversidade de configuracoes possiveis, seja para superar um determinado vao, seja para resistir a um determinado carregamento, as trelicas constituem um campo bastante fertil ao emprego de tecnicas de otimizacao. Com o emprego dessas tecnicas, busca- se quantificar o minimo de material necessario para que a estrutura suporte um determinado carregamento com a devida seguranca. Os problemas de otimizacao de trelicas sao classificados basicamente em tres categorias: otimizacao de secoes transversais, de geometria e de topologia. O presente trabalho apresenta um experimento desenvolvido na Universidade de Passo Fundo, atraves do qual objetivou-se a validacao de estudos numericos envolvendo a otimizacao de secao e de geometria de trelicas. Inicialmente, foram efetuadas diversas simulacoes com o emprego de um programa desenvolvido para a otimizacao de trelicas pelo Metodo do Recozimento Simulado (Simulated Annealing). Na sequencia, a partir dos resultados obtidos, for...
Apresentam-se resultados de uma investigacao qualitativa sobre influencias do uso tecnologias int... more Apresentam-se resultados de uma investigacao qualitativa sobre influencias do uso tecnologias interativas em sala de aula, referente a aprendizagem significativa de conceitos de Algebra Linear. Para tanto se propos o desenvolvimento e analise de dados sobre uma atividade de ensino que visou a aprendizagem significativa de sistemas lineares, propiciada pela resolucao de um problema contextualizado. A coleta de dados se deu por meio de observacoes ocorridas durante a aula, bem como por materiais escritos produzidos pelos estudantes. A analise dos dados indica que a atividade, realizada de forma colaborativa, em grupos, possibilitou por meio das reflexoes e discussoes, (re)significar conceitos sobre resolucao algebrica e sistemas de equacoes lineares. Ao perceberem seus usos na resolucao de um problema comum em suas areas de atuacoes profissionais, conseguiram relacionar conceitos das disciplinas de Estatica e de Algebra Linear. Alem disso, ao interagirem com o ambiente do software Geo...
Cold-formed profiles has been used in large scale in Building industry, due to the easy way to pr... more Cold-formed profiles has been used in large scale in Building industry, due to the easy way to product them and the wide range of sections feasible to accomplish with the project needs. The search for a maximum performance of structural elements with the low use of material is a challenge of today and future for engineering. This paper presents a numeric study to obtaining minimum weight of cold-formed channel columns, with and without lips, using the prescriptions of AISI 2007. Flexural, torsional and torsional–flexural buckling of columns was considered as constraints. The optimization was made through the method of Simulated Annealing. Several numeric simulations are presented and discussed to validate the proposal and an experimental example that qualifies the implementation. The relations between lips, web width and flange width are analyzed. Finally, the process shows excellent results to reduce the cross section area.
Dentre as diversas propostas pedagogicas, a aprendizagem por projetos tem adquirido crescente des... more Dentre as diversas propostas pedagogicas, a aprendizagem por projetos tem adquirido crescente destaque por proporcionar a construcao efetiva do conhecimento com a participacao ativa dos estudantes. Com a finalidade de consolidar o conhecimento adquirido na area de estruturas em cursos de engenharia civil, atividades envolvendo a construcao de estruturas em escala reduzida vem sendo cada vez mais empregadas. O presente trabalho relata uma atividade desenvolvida no Curso de Engenharia Civil da Universidade de Passo Fundo, caracterizada por uma peculiaridade em relacao a grande parte das atividades desse tipo: o desenvolvimento de um projeto experimental inicial, que possibilitou a elaboracao de etapas e de estabelecimento de criterios a serem utilizados nos desenvolvimentos de outros projetos semelhantes, realizado por colegas de curso. Ou seja, um grupo de alunos do Curso, constituido de bolsistas de iniciacao cientifica, foi incumbido de efetuar a proposta de uma atividade a ser des...
In order to support the structural designer with regard to the selection of structural materials,... more In order to support the structural designer with regard to the selection of structural materials, this work presents results obtained from the optimization of reinforced concrete beams and welded “I” steel beams. To achieve this objective, both problems were formulated according to Brazilian standards, considering the cost as objective function and section dimensions as design variables. For the optimization of the proposed problems, Simulated Annealing optimization algorithm was adopted. Beams were optimized considering spans from 1 up to 25 m and two different loads. To the structures analyzed, the final costs for steel beams have always been higher than reinforced concrete, but concrete beams are significantly heavier than steel beams.
Rosana Maria Luvezute Kripka Instituto de Ciências Exatas e Geociências, Universidade de Passo Fu... more Rosana Maria Luvezute Kripka Instituto de Ciências Exatas e Geociências, Universidade de Passo Fundo Brasil [email protected] Moacir Kripka Faculdade de Engenharia e Arquitetura, Universidade de Passo Fundo Brasil [email protected] Carlos Ariel Samudio Pérez Instituto de Ciências Exatas e Geociências, Universidade de Passo Fundo Brasil [email protected] Guilherme Fleith de Medeiros Faculdade de Engenharia e Arquitetura, Universidade de Passo Fundo Brasil [email protected]
The aim of this work is to present a procedure developed in order to minimize the cost of reinfor... more The aim of this work is to present a procedure developed in order to minimize the cost of reinforced concrete building frames. To achieve this objective the cross sections dimensions, the area of steel and the concrete strength of beams and columns were taken as design variables. The constraints related to dimensions and strength were based on the Brazilian standard ABNT NBR 6118 (2007). The total cost, composed by the costs of concrete, steel and formworks, was minimized by the usage of Harmony Search Algorithm (HS), an optimization method developed by Geem, Kim and Loganathan (2001), inspired by the observation that the aim of music is to search for a perfect state of harmony. The search process is compared to a musician’s improvisation process. Some structures were analyzed, and the results were compared to those obtained from the conventional design procedure, in an attempt to identify the influence of factors such as resistance class, material costs and beams/columns costs on t...
Competition among companies is growing globally, with the need to increase productivity and effic... more Competition among companies is growing globally, with the need to increase productivity and efficiency in the product sector. However, there is also a growing concern about global warming and the depletion of natural resources, as well as their effects on human health. In this context, all human activities that involve intense usage of resources must take into account sustainability as one of the decision criteria. This work presents the application of decision-making methods to define the best product mix in the agricultural machinery industry. With this objective, the current schedule of the production line was identified, along with the production flow, by performing an inventory analysis and an environmental impact study (endpoint). A total of seven alternatives for the production mix of grain trailers were defined, considering different materials and production processes. The selection of the best schedule according to the different criteria was performed through the analytic h...
Infrastructure is an indispensable and decisive requirement for the economic development of a cou... more Infrastructure is an indispensable and decisive requirement for the economic development of a country; it is directly linked to the set of structural economic activities and serves as the foundation for the development of other activities. In this context, the bridges have fundamental importance to the social and economical development of the cities, because the roads are to ensure the entry of inputs on farms, as well as the disposal of products and free movement of populations. The aim of this study is to present a survey of the existing bridges in the south region of Brazil, more specifically in the city of Pato Branco, identifying the most recurrent damages, in order to provide bases to administrators, with the intention of ensuring the correct functioning of the transport infrastructure and in the preservation of public property and security for the users. Data collection was conducted through visits, using the method of visual and photographic records. After the analysis was d...
Corresponding Author: Moacir Kripka Department of Civil Engineering, University of Passo Fundo, P... more Corresponding Author: Moacir Kripka Department of Civil Engineering, University of Passo Fundo, Passo Fundo, Brazil Email: [email protected] Abstract: The current scenario of structural engineering is guided by the growing ecological concern and constant search for efficient and economic structural solutions. In this sense, aspects related to the durability of structures have become a significant topic of study. Based on this context, the purpose of this work was to provide resources that allow the maximization of the useful life of reinforced concrete columns during the design phase. To achieve this objective, different scenarios were simulated for the properties of concrete and environmental properties and the corresponding transversal cross-sections were defined with the usage of an optimization method. The results obtained showed that the parameters that most interfere in the durability of the structure are the covering thickness and the compression strength. It was found that the ...
O objetivo do presente trabalho e estudar a importância da consideracao da sequencia de carregame... more O objetivo do presente trabalho e estudar a importância da consideracao da sequencia de carregamento e construcao, na analise de edificios, bem como as formas de melhor simular esta sequencia. Com esta finalidade foi desenvolvido um programa de computador, baseado no metodo dos deslocamentos, que efetua a analise tanto pelo procedimento convencional como pelo procedimento incremental construtivo. Este ultimo permite a obtencao nao apenas dos esforcos finais como tambem dos desenvolvidos durante uma determinada etapa de construcao, podendo-se reproduzir os efeitos do processo de escoramento e da construcao das alvenarias ou ainda efetuar a pesquisa dos esforcos extremos, entre outras facilidades. Atraves dos exemplos analisados foi possivel comprovar que o procedimento convencional de analise conduz a resultados pouco confiaveis, sendo portanto o procedimento incremental indispensavel para que se aproxime as reais condicoes a que as estruturas sao submetidas.
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica
When designing a building, the selection of the most appropriate structural material may be based... more When designing a building, the selection of the most appropriate structural material may be based on several factors such as cost, performance, availability, and, more recently, the possible environmental impacts produced. One way to select the best alternative based on several criteria may be the use of decision-making techniques. Multicriteria decision analysis standardizes the decision-making process through mathematical modeling, helping the decision maker to solve problems in which there are several objectives to be achieved simultaneously. Among the existing methods, one of the most widely used is the Analytic Hierarchy Process (AHP), which is based on the division of the decision problem into hierarchical levels and the paired comparison. The present work had as objective to present a methodology employed to compare three types of structural materials, concrete, steel and wood, according to both objective and subjective criteria. Among the results obtained, it was found that, despite the lower environmental impact attributed to the wood, as well as the better strength of steel, concrete was the material that presented the best total score, mainly due to its lower cost and to cultural aspects.
Journal of Construction Engineering, Management & Innovation
The application of optimization to the solution of practical structural engineering problems has ... more The application of optimization to the solution of practical structural engineering problems has been very limited, despite the great development of the techniques. One of the main reasons for this is the complexity of the generated models, which employ nonlinear functions and generate a space of nonconvex solutions. In addition, most design variables, as in the case of steel profiles, can only assume discrete values. Traditional methods of mathematical programming are very limited in solving problems with these characteristics, opening space to the usage of heuristic methods and, more specifically, to metaheuristic methods. The main advantage of this class of methods is the fact that they only involve values of the functions in the optimization process, regardless of the existence of unimodality or even continuity in the derivatives of the functions involved. The present work presents the application of a heuristic method, the simulated annealing method, to the optimization of steel trusses with parallel chords, also called flat trusses. Initially, several usual configurations of trusses were analyzed, aiming to identify which led to the lowest cost. The top chord coordinates were also included as design variables, with the purpose of verifying the relations between span and height normally indicated in the literature as the most economical. Among the results, it was verified that the inclusion of the height of the truss among the design variables can lead to a significant additional cost savings.
International Journal of Environmental Research and Public Health
The application of techniques to analyze sustainability in the life cycle of small-span bridge su... more The application of techniques to analyze sustainability in the life cycle of small-span bridge superstructures is presented in this work. The objective was to obtain environmental and economic indicators for integration into the decision-making process to minimize the environmental impact, reduce resource consumption and minimize life cycle costs. Twenty-seven configurations of small-span bridges (6 to 20 m) of the following types were analyzed: steel–concrete composite bridges, cast in situ reinforced concrete bridges, precast bridges and prestressed concrete bridges, comprising a total of 405 structures. Environmental impacts and costs were quantified via life cycle environmental assessment and life cycle cost analysis following the boundaries of systems from the extraction of materials to the end of bridge life (“from cradle to grave”). In general, the results indicated that the environmental performance of the bridges was significantly linked to the material selection and bridge...
Engineering, Construction and Architectural Management
PurposeThe fair wage potential (FWP) is a social assessment method that can serve as an important... more PurposeThe fair wage potential (FWP) is a social assessment method that can serve as an important measure to estimate the related social impacts along a product's life cycle; however, it does not admit a direct relation to the functional unit. This research presents the weighted fair wage potential (WFWP) method that relates the functional unit to the FWP. It is a simplified method to connect the material inventory to social data. This study aims to develop an approach to assess and choose the best construction typology for buildings based on the social sustainability of workers involved in the sectors.Design/methodology/approachThe study is presented in phases. Phase 1 selected and identified two Brazilian house projects, which were considered for the following processes: extraction of raw materials, manufacture of building materials and housing construction. Phase 2 assembled the social life cycle inventories and executed them using the social life cycle assessment (SLCA). The...
International Journal of Structural Glass and Advanced Materials Research
Concrete is one of most used materials in construction and also one of the main responsible for t... more Concrete is one of most used materials in construction and also one of the main responsible for the emission of carbon dioxide, or CO 2 , in the atmosphere. Thus, in order to study ways to reduce this impact, it is important to evaluate the influence of each raw material of the reinforced concrete, as well as the phases of the life cycle in which these impacts are more relevant. This paper presents a review of recent studies related to carbon dioxide emissions of the materials of reinforced concrete. In this review, we sought to identify the phases of the life cycle of reinforced concrete most focused by researches. It was found that the cement production stage is the most contemplated in the studies, many of them focusing on the additions of complementary cementitious products, since cement is among the materials that contributes decisively to the total CO 2 emissions. The structure sizing, with the definition of concrete strength to be adopted in the design, were also extensively investigated, since these are phases in which it is identified a greater possibility of contribution, by the researchers, for the minimization of the impacts.
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica
In a built environment, practice of sustainability is a responsibility of all involved in the des... more In a built environment, practice of sustainability is a responsibility of all involved in the design and execution. Most of the measures should be used in the design stage, in which there are the greatest implications regarding the dimensions, specifications and details incorporated into the structure. Therefore, prior identification and study of the impacts generated in the environment allow professional, company or public agencies to develop action plans and innovative solutions focused on reducing of negative impacts. This paper shows a literature review on the alternatives applicable in the project phase, in order to minimize the environmental impact of reinforced-concrete buildings. Initially, a brief history and a contextualization about sustainability has been presented. After, this work relates studies in civil engineering, with an emphasis on structural design. The proposed alternatives include the role of each professional in the project development, such as studies and applications on sustainable concrete, including the relationship between structural optimization and environmental impacts of reinforced-concrete buildings. Thus, it was possible to conclude that with these avaliable options, designer must verify which one will result better results with lower expenses and consumption of labor, financial and structural resources.
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Papers by Moacir Kripka