Engenharia Civil

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http://repositorio.ufes.br/handle/10/17613

Programa de Pós-Graduação em Engenharia Civil

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URL do programa: http://www.civil.ufes.br/pos-graduacao/PPGEC

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Análise comparativa da estimativa do coeficiente de permeabilidade de solos por redes neurais artificiais e métodos estatísticos
(Universidade Federal do Espírito Santo, 2023-02-17) Moreschi, Morgana; Bicalho, Katia Vanessa; https://orcid.org/0000-0002-2157-7322; http://lattes.cnpq.br/9639299365620025; http://lattes.cnpq.br/5099811764251015; Romanel, Celso; https://orcid.org/0000-0002-8812-3456; http://lattes.cnpq.br/1721981607189967; Hisatugu, Wilian Hiroshi; https://orcid.org/0000-0001-8333-0539; http://lattes.cnpq.br/6597878238749014; Ferreira, Silvio Romero de Melo; https://orcid.org/0000-0002-5760-1494; http://lattes.cnpq.br/8035357058902261; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
This research analyzes and compares the performance of artificial neural networks (ANN), statistical methods and empirical and semi-empirical correlations in predicting values of the permeability coefficient of saturated soils (ksat), from index properties that characterize the particle size distribution and the fine fraction. 8258 experimental data of ksat of soils composed of coarse and fine grains (2.50x10-13  ksat (m/s)  4.50x10-2 ), published in 08 databases in the literature, were compiled and compared, in order to assist in the understanding of the hydraulic properties of saturated soils and in the description of ksat prediction problems. Subsequently, a set of samples was selected and analyzed with a combination of different input variables for predicting log(ksat), using multiple linear and polynomial regression and ANN. The input variables considered were percentage of fines (silt and clay) (%Fines), liquid limit (LL), effective diameter (d10), uniformity coefficient (Cu) and void ratio (e). The results were evaluated based on the values of the coefficient of determination, the root mean square error and the mean absolute error. The performance of the ANNs surpassed the regressions and correlations in the literature. Of all the results of the analyses performed, ANN302, which considered %Fines, LL, Cu and d10 as independent variables, presented, numerically, the best results. The addition of a third hidden layer reduced the accuracy of the networks. The regressions and ANNs were better than the empirical correlations for the prediction of ksat, for the investigated database, and showed that the choice of variables that characterize the particle size distribution and the fine fraction was satisfactory for the experimental database. Considering that ksat is a highly variable property and a function of several interdependent properties, the ANN technique proved to be viable, mainly because it does not require prior knowledge of the mathematical relationship between the variables and because of its ability to describe problems of greater complexity. The importance of including information on the particle size and nature of the fines in ksat databases is highlighted, mainly for characterizing the permeability of samples with hydraulic properties dominated by the fine fraction.
ANÁLISE COMPARATIVA DA ESTIMATIVA DO INDICE DE COMPRESSÃO DE ARGILAS POR REDES NEURAIS ARTIFICIAIS E CORRELAÇÕES EMPÍRICAS
(Universidade Federal do Espírito Santo, 2019-11-01) Oliveira Filho, Amandio Gonçalves de; Bicalho, Katia Vanessa; https://orcid.org/; http://lattes.cnpq.br/9639299365620025; https://orcid.org/0000-0003-0605-5830; http://lattes.cnpq.br/6546712936487518; Romanel, Celso; https://orcid.org/; http://lattes.cnpq.br/; Hisatugu, Wilian Hiroshi; https://orcid.org/; http://lattes.cnpq.br/; Frasson, Antonio Manoel Ferreira; https://orcid.org/; http://lattes.cnpq.br/; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
The compression index (CC) and the compression ratio (CR) are used to calculate consolidation settlement of foundations on soft soils when requested by external loads. Several empirical correlations have been published in the literature to predict CC and
Análise da emissão de CO2 de sistemas de piso misto composto por vigas celulares via algoritmos metaheurísticos
(Universidade Federal do Espírito Santo, 2023-08-23) Silva, Gabrieli Fontes; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509; https://orcid.org/0009-0001-1758-0238; http://lattes.cnpq.br/7583532122245733; Junges, Elisabeth; https://orcid.org/0000-0002-9094-2645; http://lattes.cnpq.br/4385254860391051; Silva, Amilton Rodrigues da; https://orcid.org/0000-0001-7122-2688; http://lattes.cnpq.br/1804042130645206
The increase in greenhouse gas emissions in the construction sector has led to the search for economically and environmentally more viable solutions. In recent years, there has been a growing adoption of mixed floor systems with full-depth beams. However, cellular beam floor systems have been relatively unexplored despite their advantages over full-depth beams. These advantages include the ability to span larger distances with reduced structural mass and, consequently, reduced CO2 emissions. The aim of this study is to present the optimization problem formulation for a mixed steel and concrete floor system composed of cellular beams, a steel deck slab, and steel columns. In addition to constraints related to ultimate and serviceability limit states, construction constraints related to cutting and welding were considered in the optimization problem. The solution was obtained through Genetic Algorithm and Particle Swarm Optimization. The design variables included not only beam sizing parameters but also the choice of the steel deck slab, the compressive strength of the concrete in the slab, the number of secondary beams in the floor, and the steel profile of the columns. An analysis of CO2 emissions was conducted for the optimal solutions found for the mixed floor system with cellular beams, comparing them to the mixed floor system with full-depth beams. The results indicated a reduction in emissions of over 30% when using the cellular beam system. Furthermore, it was found that constraints related to the cutting and welding process of cellular profiles did not have a significant contribution to the final floor emissions. This points to the environmental feasibility of using this type of beam.
Análise da interação solo-atmosfera em solos argilosos compactados não saturados: relação entre evaporação e sucção (ou umidade volumétrica)
(Universidade Federal do Espírito Santo, 2023-09-06) Poleto, Thiago Luiz; Bicalho, Katia Vanessa; http://lattes.cnpq.br/9639299365620025; http://lattes.cnpq.br/2670879835444801; Zuquette, Lazaro Valentim; Dantas, Bruno Teixeira; http://lattes.cnpq.br/9702567694302789; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
In this work, the influence of soil-atmosphere interaction is evaluated in a monitored experimental landfill divided into two symmetrical sections built with compacted clay soils treated with lime exposed to the same atmospheric conditions in Hericourt, Haute Saône region, France. For illustrating the influence of such interaction, data from monitoring soil moisture and suction and climatic conditions are presented and discussed. Potential Evaporation (Ep) values were calculated considering empirical formulations selected from the literature, commonly used and based on measurements of air temperature and relative humidity at the location. The analyzes carried out use climate data collected at a meteorological station built at the site of the landfill being monitored under study. The main objective of the work is to compare the potential evaporations (Ep) calculated by the selected empirical methods with the suction and volumetric humidity data measured in unsaturated compacted clayey soils on the surface of the landfill constructed in the study region. The measured variations of (θw) and (s) on the compacted surfaces of the two lime-treated soils (a high-plasticity clay and a low-plasticity clay) show consistency with local seasonal climatic variations. During the water deficit from May to June 2011, the measured suction values (s) increased consistently and the corresponding θw decreased, suggesting a relatively significant water evaporation effect. In the s x Ep relationship, from April to June 2011 for the empirical methods Ep based on air temperature exhibited a more substantial increase in evaporation with increasing soil suction. The empirical method based on air temperature and relative humidity did not adequately describe the water balance during the drying period. It is noteworthy that to apply the empirical methods for calculating Ep selected in these works to any location, a study with a larger database measured from different regions over several years is necessary.
APLICAÇÃO DE REDES NEURAIS ARTIFICIAIS NA ESTIMATIVA DE CURVAS DE RETENÇÃO DE SOLOS BRASILEIROS
(Universidade Federal do Espírito Santo, 2020-05-29) Totola, Lucas Broseghini; Bicalho, Katia Vanessa; https://orcid.org/; http://lattes.cnpq.br/9639299365620025; https://orcid.org/; http://lattes.cnpq.br/; Dantas, Bruno Teixeira; https://orcid.org/; http://lattes.cnpq.br/9702567694302789; Hisatugu, Wilian Hiroshi; https://orcid.org/; http://lattes.cnpq.br/; Mascarenha, Marcia Maria dos Anjos; https://orcid.org/; http://lattes.cnpq.br/; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
ABSTRACT The constitutive relationship between water content or degree of saturation and suction is determined soil-water retention curve (SWRC). The understand of the SWRC is important in the unsaturated soil mechanics study and in solving geotechnical e
Comparação entre os valores de limite de liquidez obtidos pelos métodos de Casagrande e cone para diferentes solos argilosos
(Universidade Federal do Espírito Santo, 2018-05-28) Crevelin, Letícia Garcia; Bicalho, Kaia Vanessa; Alves, Elcio Cassimiro; Frasson, Antônio Manoel Ferreira; Oliveira Filho, Waldyr Lopes de
In this present study, is highlighted the importance of specifying the procedure and equipment used to determine the liquid limit (LL) of a clay soil. The results of LL, obtained by percussion method proposed by Casagrande (LLc) and by the cone penetration method (LLp), measured by different operators and at different laboratories of clayey soils from different mineralogies and geological origins were compared. The LLp values were determined using British cone (20 mm fall cone penetration) and LLc values were determined using different hardnesses of Casagrande apparatus. Eight data base groups of LLc and LLp were evaluated, grouped according to the hardness of the percussion apparatus, mineralogy and LL value of the clayey soils. The experimental results using simple linear regression shows that the correlations between the two methods vary with the mineralogy of the clayey soil and the hardness of the base of the apparatus to the percussion. The liquid limit results obtained for kaolinites and ilites or low LL soils indicated LLp > LLc. The LL results of montmorillonites or soils with high LL value showed that there is greater dispersion among the correlations between both methods and that LLp < LLc. Residual statistical tests showed that, despite the high values of determination coefficients obtained, some linear correlations defined in this study are not valid or should be used with caution. The correlations were valid for montmorillonites (for clay content higher than 30%) and for clayey soils of several mineralogies with LL between 20-80% (this only for hard base percussion apparatus). It should be emphasized that this study seeks to stimulate the critical evaluation of the previously published correlations and those that will be elaborated in the future, and not to exhaust the subject about obtaining correlations between geotechnical tests
Desenvolvimento de sistema de baixo custo para medida do teor de umidade em solos não saturados baseado na técnica de Reflectometria no Domínio do Tempo - TDR
(Universidade Federal do Espírito Santo, 2017-07-28) Somensi, Cauê Stocchi; Esquivel, Edmundo Rogério; Bicalho, Kátia Vanessa; Alves, Elcio Cassimiro; Giacheti, Heraldo Luiz
The determination of moisture content is important in the design and construction stages of geotechnical works. The TDR - Time Domain Reflectometry technique stands out among the several methods for estimating the moisture content in unsaturated soils. The TDR tests present similar results to those determined through of the standard gravimetric method, with the advantage of promoting instantaneous measurements with non-destructive characteristics. In addition, they enable the portability and systems embedding. However, due to the its construction characteristics and working methodology, it considers a large number of variables, becoming complex and subject to inaccurate results. Currently, it is common the need for high investments for the acquisition of hardware and commercial software. The aim of the present work is the development of a low cost TDR system, including a control and analysis software. Features such as measurements by scheduling, automatic estimation of conductivity and moisture content. These estimates are made through calibration equation that can be provided to the software. Customized TDR probes have also been developed to work integrated with the proposed system, being manufactured with the 3D printing technology. Using solution with different concentrations of acetic acid, comparative tests were performed between the low cost TDR system and the TDR system formed by the TDR100 device and PC-TDR software, developed by Campbell Scientific Inc. The results show that with proper calibrations, the proposed system can be used for soil water content estimation in an efficiently and reliably way, with a standard error of the estimate of around 1%. The low cost TDR system was promising and could stimulate the use of TDR technique, increasing the alternatives of geotechnical testing apparatus in unsaturated soils.
Dimensionamento otimizado de vigas mistas alveolares por meio de algoritmos genéticos
(Universidade Federal do Espírito Santo, 2019-08-30) Ramos, Jose Ronaldo Soares; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509; https://orcid.org/; http://lattes.cnpq.br/8535225615285995; Rosa, Rodrigo de Alvarenga; https://orcid.org/0000-0003-0841-514X; http://lattes.cnpq.br/7706827408886021; Mappa, Paulo Cesar; https://orcid.org/0000-0001-8192-8991; http://lattes.cnpq.br/0342332166757546
The objective of this work is to present the formulation of the optimization problem and its applications for composite beams of steel e concrete with web openings. The implementation of the program was made in Matlab platform using the guide tool. The formulation of the problem was based on the studies of Lawson e Hicks (2011), described in the European Design Guide SCI Publication P355 with appropriate adaptations to NBR 8800:2008. The optimization problem was solved using Genetic Algorithm, because it is a discrete problem. Validation examples are presented and a study of the predominant collapse modes has been done to show the application and the advantages of the proposed formulation. A numerical analysis by the Finite Element Method was made for to demonstrate the predominant mode of collapse. The results found pointed out that the application of the genetic algorithm for this type of problem leads to more economical solutions when compared to the examples found in the specialized literature
Elaboração de rotas para atendimento às requisições de transporte das plataformas offshore de petróleo
(Universidade Federal do Espírito Santo, 2017-12-14) Vieira, José Reynaldo Gama; Rosa, Rodrigo de Alvarenga; Alves, Elcio Cassimiro; Resendo, Leandro Colombi
abstract
Estimação da vida útil remanescente de trilhos ferroviários por meio de técnicas de aprendizado de máquina
(Universidade Federal do Espírito Santo, 2019-08-27) Rocha, Gledson Fabio Cotrim; Rosa, Rodrigo de Alvarenga; https://orcid.org/0000-0003-0841-514X; http://lattes.cnpq.br/7706827408886021; https://orcid.org/; http://lattes.cnpq.br/8893742420123850; Cavalieri, Daniel Cruz; https://orcid.org/0000-0002-4916-1863; http://lattes.cnpq.br/9583314331960942; Sabino, Jodelson Aguilar; https://orcid.org/0000-0003-1690-7849; http://lattes.cnpq.br/5946878012544656; Krohling, Renato Antonio; https://orcid.org/; http://lattes.cnpq.br/5300435085221378; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
As the rail is the costliest element on the permanent track, finding tools to estimate the remaining life is important to make the most of them. Thus, it has hypothesized that machine learning algorithms trained from historical databases can assist the planner in performing this estimation. Two machine learning algorithms were tested: Artificial Neural Network (RNA) and Nearest K-Neighbors (k-NN). The historical databases used were from Vitória to Minas Railway (EFVM). The dataset has 1,275,034 records for the period of 6 years and 8 months. The RNA had 5 neurons in the input layer: 1) the degree of the curve; 2) internal or external rail curve; 3) the width of the rail; 4) the height of rail; and 5) average weight carried. The intermediate layer, regardless of the category for estimating the remaining rail life, had variations of 1, 2 and 3 layers and variations in the number of neurons of 30, 50, 100, 200 and 400. The output layer depends on the period category the remaining useful life of the rails: 1) month, with 80 neurons, 2) quarter, with 27 neurons, 3) semester, with 14 neurons and 4) year, with 7 neurons. For the k-NN algorithm, configurations ranging from k = 5, 7 and 9 were tested. For both algorithms, k-fold cross validation was applied, with f = 10, and performance was evaluated using the accuracy value and F1-score. The programming language was Python and the Scikit-Learn library. RNA configurations and k-NN configurations were compared and k-NN showed superior results to RNA. However, both algorithms reached the objective proposed in this dissertation, which was the estimation of the remaining rail life in order to help the railroad maintenance planner to replace the rails, where they obtained results in accuracy and F1-score higher than 80% for both algorithms for the semester and year period categories, these period categories being most used by rail operators. The k-NN algorithm always obtained better results when compared to RNA
ESTUDO ANALÍTICO DE VIGAS MISTAS DE AÇO E CONCRETO COM PROTENSÃO EXTERNA VITÓRIA
(Universidade Federal do Espírito Santo, 2021-03-12) Turini, Thiago Tononi; Calenzani, Adenilcia Fernanda Groberio; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879; https://orcid.org/; http://lattes.cnpq.br/; Kataoka, Marcela Novischi; https://orcid.org/; http://lattes.cnpq.br/; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
Composite steel and concrete beams with external prestressing is an underused structural system in Brazil due in part to the lack of standardization for its calculation. This work aims to propose a methodology for the analysis and design of composite stee
Estudo da variação da tensão admissível com a dimensão de sapatas apoiadas em subsolos arenosos
(Universidade Federal do Espírito Santo, 2018-05-30) Souza, Marco Wilker Figueiredo de; Bicalho, Kátia Vanessa; Alves, Elcio Cassimiro; Dantas, Bruno Teixeira; Frasson, Antônio Manoel Ferreira
The dimension of the footings is a factor of influence in the calculations of the bearing capacity and predictions of settlements of superficial foundations (for example, footings) on sandy soils. The study of the variation of the allowable stress design with the footings size allows to identify the most economical dimension of the footings for each pillar of the work, and to define the value of the allowable stress and the size of the footings that defines the highest possible allowable stress (B *) for the study case. In this dissertation it is evaluated some theoretical and semi-empirical methods adopted in the literature to predict the bearing capacity and settlements of footings in sandy soils by means of experimental results obtained in the literature, of load tests performed on real footings and plates of different sizes on sandy soils. The value of the deformation modulus of each adopted sublayer of the sandy soil is a determinant factor for the methods of settlements predictions, investigated in this study (Schmertmann, 1970; Schmertmann et al., 1978). It is observed the influence of the adopted correlations between the results of field tests SPT and cone penetration CPT in the predicted settlements. It is concluded that the size of the footing in sandy soils that define the allowable stress design of the shallow foundations analyzed in this study varied from 1.7m to 3.4m, according to the geotechnical parameters and to the adopted model of calculation methods. The higher the value adopted for the deformability module, higher the value of B*, and greater is the probability of the rupture to define the allowable stress design.
Estudo paramétrico do comportamento geotécnico de estruturas de contenção de solo reforçado
(Universidade Federal do Espírito Santo, 2018-02-26) Sarmento Junior, Rogério Gonçalves; Dantas, Bruno Teixeira; Bicalho, Kátia Vanessa; Alves, Elcio Cassimiro; Romanel, Celso; Ehrlich, Maurício
The use of reinforced soil wall (RSW) is a geotechnical response to the quick human dense settlement in urban areas. Techniques that insert elements in the soil mass in order to improve its resistance are very ancient in engineering history. In 1966, French architect Henry Vidal developed the first RSW design method, known as Terre Armée (Reinforced Soil). Currently, the development of new materials and construction techniques have enabled RSW to become more complex and sophisticated. Analysing the influence of the soil compaction and of the facing structure allows a deeper understanding of geotechnical behaviour of RSW. In order to evaluate the impact of soil compaction and facing system in RSW, this work performs computational analyses in different RSW using the finite element method. The finite element method was adopted because it provides more accurate and direct representation to complex real problems such as earthwork structure behaviour. The CRISP92-SC, software created on Cambridge University, performed a computational simulation of RSW. The Modified K-Stiffness (2008) and Dantas and Ehrlich (2000) calculation method were used and their results compared to those obtained in numerical simulations. Initially, the influence of the element of discretization was checked using the finite element mesh. The goal was to investigate if the use of different mesh elements could lead to distinct results to the same problem. In a second time, the impact of the compaction and of the type of facing used was verified. For that, results from Almeida (2014) together with the data obtained from this research for structures submitted to the compaction process were employed. The results showed that the compacting had a great influence on the final behaviour of the RSW. Its influence does not correspond only to the effect usually attributed to compaction in common earthwork calculations. Other effects were detected. Ignoring this fact can underestimate the stress on the reinforcement at the lower depths of RSW. The RSW facing structure may also exert a great influence on deformation and on resistance. Some types of facing could have a relevant impact on restricting the displacement of RSW base and their effect should not be neglected.
Modelo computacional avançado para análise de estruturas sob ação de gradientes térmicos
(Universidade Federal do Espírito Santo, 2019-12-16) Neves, Natan Sian das; Azevedo, Macksuel Soares de; https://orcid.org/0000000330113420; http://lattes.cnpq.br/6726295161401220; https://orcid.org/0000-0002-4679-0461; http://lattes.cnpq.br/3669643833173206; Silva, Valdir Pignatta e; https://orcid.org/0000-0003-3302-8520; http://lattes.cnpq.br/2431468701531047; Camargo, Rodrigo Silveira; https://orcid.org/0000-0001-9850-7018; http://lattes.cnpq.br/8613621447589176; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
Structural modeling of thermal effects has important practical applications in engineering, corroborating the continuing interest of academic scientific research in the field. In particular, since structural elements are subjected to high temperatures, the properties of the materials used in the structures deteriorate with increasing temperature, resulting in a considerable loss of strength and stiffness. Under these conditions, the structures present complex behaviors associated to nonlinear mathematical models, requiring advanced calculus analysis. Thus, current research aims to study the performance of structures under fire action. To this end, a computational model called NASEN (Numerical Analysis Software for Engineering) was developed, containing specific modules for physical engineering areas. For the characteristics of the research, highlight, firstly, the module for thermal analysis in structures, where the nonlinear transient two-dimensional heat conduction is studied. Then, the module for thermo-structural analysis is based on the solution of a coupling of sequential numerical processes, that is, the temperature field at the cross-sectional level is first determined and, subsequently, the mechanical response is obtained based the fiber model and nonlinear structural procedures. The numerical experiments carried out during the research transited about problems of thermal and structural nature, associated to the linear and nonlinear behaviors, well were tested different geometries, boundary conditions and types of materials. The numerical experiments carried out during the research transited about problems of thermal and structural nature, associated to the linear and nonlinear behaviors, where were tested different geometries, boundary conditions and types of materials. In general, the results obtained with the computer simulations led to satisfactory responses when compared to the experimental measurements, numerical or analytical solutions available in the literature.
Modelo matemático para planejamento da distribuição de locomotivas em pátios ferroviários para atendimento à demanda de formação de trens
(Universidade Federal do Espírito Santo, 2015-08-26) Nascimento, Fabiano Cézar Gomes; Rosa, Rodrigo de Alvarenga; Alves, Elcio Cassimiro; Sabino, Jodelson Aguilar
Rail transport has high operating costs and a major challenge is to reduce these costs so that such transport can be competitive. In a railroad there is a vast playing field with opportunities to implement improvements that optimize the use of railroad assets, and one of the main difficulties lies in the locomotives distribution planning in rail yards to meet the demand for trains formation. The major problem of locomotives distribution planning is the situation where there is a demand for locomotive in a certain rail yard in a certain time, but there is not enough locomotives to meet the demand and then it is necessary to move locomotives from one rail yard that has locomotives without demand to this rail yard that has demand. The locomotives can be moved from one rail yard to another in two ways, the first is when it travels coupled to another locomotive that tows, Deadheading, and the second when the locomotive travels alone and can only attach itself to other locomotives, Light Traveling. This paper aims to propose an Integer Programming mathematical model for the Locomotive Assignment Problem, which minimizes the costs of distributing locomotives. The model objective function aims to meet all the locomotive demand, minimizing the distribution costs sum, Deadheading and Light Traveling. In addition, the model prioritizes the distribution of larger capacity locomotives to meet the demand. It is also proposed the introduction of virtual locomotives to meet the demands that have not been met. These locomotives are used to indicate that the demand in that rail yard at certain time will be missed, so that the railroad professionals may take actions in order to deliver locomotives that rail yard and time or assume that demand will not be met. Tests in instances based on real data of the railroad Vitória to Minas (EFVM) were solved optimally using the solver CPLEX 12.6 and proved to be very adherent in operational use for support and decision making with regard to planning and distribution locomotives in rail yards to supply the trains training demand.
Modelo matemático para planejamento da logística reversa de pneus inservíveis com base no modelo two-echelon capacitated vehicle routing problem
(Universidade Federal do Espírito Santo, 2016-02-29) Fraga, Karina Pedrini; Ribeiro, Glaydston Mattos; Rosa, Rodrigo de Alvarenga; Alves, Elcio Cassimiro; Mauri, Geraldo Regis; Chaves, Gisele de Lorena Diniz
The number of vehicles circulating in the world has grown quickly, demanding rubber tires that can wear out by time out and need to be replaced. These tires must be disposed of properly after the end of their useful life as it can generates environmental and health problems. Alongside the growth of tire’s use, legislation has been created in order to establish the planning of reverse logistics of postconsumer products and also, the research in the field of reverse logistics, involving environmental factors, has been growing too. The Two-echelon capacitated Vehicle Routing Problem (2E-CVRP) is a vehicle routing problem into two levels which performs the goods’ distribution from the storage to the customers with the help of intermediate storages. From the perspective of reverse logistics, the 2E-CVRP enables the collection of waste products to their final disposal and/or recycling. In this context, this work proposes a new 2E-CVRP class, which was called Two-echelon capacitated Vehicle Routing Problem with Heterogeneous Fleet and Site Dependence (2E-CVRP-HFSD) for the planning of reverse logistics of waste tires. As a differential, the model considers the possibility of heterogeneous fleet on the second level of the problem and access restrictions for some vehicles to certain customers, according to the size of the vehicle. In addition, its objective function considers the fixed transport costs involved in the problem and not only variable transport costs, travel costs and the operating cost of the loads on satellites. The model was applied to the reverse logistics of waste tires in the state of the Espírito Santo. From the definition of 22 instances and by using the CPLEX solver 12.6, it was solved, optimally, 19 of the 22 defined instances, presenting gaps in the maximum 8.99% after a running time of 7200 seconds in the instances not solved optimally. This research contributed to the literature by presenting a new variation to 2E-CVRP model and treat the resolution of the reverse logistics of tires, as commonly the 2E-CVRP is modeled for distribution of goods and here it was developed forconsolidation, in a reverse flow.
OTIMIZAÇÃO DA EMISSÃO DE CO2 DE SISTEMAS DE PISOS MISTOS VIA ALGORITMOS METAHEURÍSTICOS DISSERTAÇÃO
(Universidade Federal do Espírito Santo, 2022-07-29) Arpini, Paulo Augusto Tonini; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509; https://orcid.org/0000000170665030; http://lattes.cnpq.br/; Kripka, Moacir; https://orcid.org/; http://lattes.cnpq.br/; Calenzani, Adenilcia Fernanda Groberio; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879
abstract
PLANEJAMENTO DA DISTRIBUIÇÃO DE CARGAS NO CONTEXTO DA LOGÍSTICA URBANA CONSIDERANDO A INTEGRAÇÃO DO TRANSPORTE AQUAVIÁRIO COM O TERRESTRE
(Universidade Federal do Espírito Santo, 2022-06-28) Carli, Amabile Cucco de; Rosa, Rodrigo de Alvarenga; https://orcid.org/0000-0003-0841-514X; http://lattes.cnpq.br/7706827408886021; https://orcid.org/; http://lattes.cnpq.br/; Mauri, Geraldo Regis; https://orcid.org/0000-0002-8393-7741; http://lattes.cnpq.br/7870111209439581; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
Retail companies have been looking for new transport alternatives for delivering cargo within cities in order to reduce their transport costs. In the context of cities that have waterway, maritime, or river connections, the integration of waterway transport with land transport is an interesting alternative, since restrictions on access to trucks have become increasingly present in urban centers. Therefore, this dissertation proposes an integrated cargo distribution strategy combining waterway and land transport. The use of public passenger Waterway Terminal infrastructure is considered to also receive cargo ships and, in parallel, generate alternative revenue for the State. Data from the municipalities of Vitória, Cariacica, and Vila Velha were chosen to test the proposed model since the government of the State of Espírito Santo (ES) is implementing a waterway passenger transport system between these three municipalities. To plan the two types of transport in an integrated way, a mathematical model inspired by the Twoechelon Capacitated Routing Problem (2E-CVRP) was created, considering a two-step distribution, multiple trips, time window, and access restriction. The first stage refers to waterway transport, which includes ships traveling between the Cargo Consolidation Center (CCC) and Waterway Terminals. The second stage, which is carried out by land vehicles, such as bicycles and motorcycles, concerns the route between the Waterway Terminals and the final customers. To solve the model, CPLEX 12.20 was used and the results indicated that the use of Waterway Terminals is a functional strategy and presents better results when integrated with the terrestrial fleet of bicycles with multiple trips. In addition, it was found that having a greater number of points for berthing ships, that is, greater availability of more Waterway Terminals, reduced the transportation costs by up to 6%.
Planejamento da logística de suprimento de plataformas offshore por meio de um modelo matemático 2L-CVRP com frota heterogênea e equilíbrio náutico
(Universidade Federal do Espírito Santo, 2015-06-01) Arpini, Bianca Passos; Rosa, Rodrigo de Alvarenga; Mauri, Geraldo Regis; Resendo, Leandro Colombi; Alves, Elcio Cassimiro
Oil is an important resource in today's world and its exploitation in Brazil is based mainly on deepwater exploration, for which offshore platforms are deployed. As these platforms are isolated and distant from the Brazilian coast, it is essential to plan the supply logistics, which includes, among other elements, the offshore support vessels, which are responsible for supplying the platforms and are an expensive resource. On logistics systems, is essential to plan and manage the activities of freight transport, because the transport costs represent a large portion of total logistics costs. Therefore, in the analyzed context, it is important to minimize transportation costs through efficient planning of the supply vessel. In this sense, there are two central aspects in the management of logistics distribution: Vehicle Routing Problems, used to determine the optimal route, and Loading Problems, used to define the best way of carrying goods in vehicles used for transport. Aiming to create routes and the two-dimensional storage of cargo, has been proposed in the literature the Capacitated Vehicle Routing Problem with Two-dimensional Loading Constraints (2L-CVRP). This essay aims to propose a mathematical model of Mixed Integer Linear Programming based on 2L-CVRP applied to planning the supply logistics of offshore platforms to create routes considering the nautical balance and better storage of cargo on deck, named Weight Balance Two-Dimensional Loading Heterogeneous Fleet Vehicle Routing Problem (WB2L-HFVRP). This model differs from other models because it considers heterogeneous fleet and uses a objective function that aims to minimize the number of ships, sailed distance, and the difference between the weights distributed between the sides of the ship, the nautical balance. Tests on instances based on real data from Petrobras were made in CPLEX 12.6 and showed a reduction of up to 25% compared to the actual sailed distance.
Planejamento das atividades e da utilização dos recursos na operação de vagões em terminais ferroviários
(Universidade Federal do Espírito Santo, 2018-03-22) Pimenta, Lucas de Barros; Rosa, Rodrigo de Alvarenga; Alves, Elcio Cassimiro; Resendo, Leandro Colombi; Sabino, Jodelson Aguilar
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