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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Agora exibindo 1 - 20 de 20

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/0000-0002-2157-7322; http://lattes.cnpq.br/9639299365620025; https://orcid.org/0000-0003-0605-5830; http://lattes.cnpq.br/6546712936487518; 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; Frasson, Antonio Manoel Ferreira; https://orcid.org/; http://lattes.cnpq.br/8909318465989135; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
The compression index, CC, and the compression ratio, CR, obtained through a unidimensional compression laboratory test, normally called consolidation test, are usually used to calculate the consolidation settlement of soft clay soils when requested by external loads. Several empirical correlations have been published in the literature to predict CC and CR values for different soft soils as a function of their index properties. The multiplicity of published correlations to estimate CC and CR indicates the need for selection criteria in their use. This research investigates a database of 2,022 soft soil samples from different geological sites in Brazil and other countries. The objective of this study is to evaluate the prediction capacity of the compression index and the compression rate through empirical correlations previously published in the literature and by empirical correlations of adjustments proposed in this research, compared to the use of Artificial Neural Networks (ANNs). Artificial neural networks were trained with the Levenberg-Marquardt algorithm, with one or two hidden layers operating sigmoid activation functions and an output layer activated by a linear function. The ANNs are trained in different groups, first with all soil samples from the dataset, and then only with soil samples from the Brazilian coast, in order to evaluate the generalization capacity of ANNs. Forecasting performance have been assessed using statistical techniques that include: (i) the root mean square error (RMSE), (ii) the estimated and measured compression index ratio (K), (iii) the ranking index (RI) and (iv) the ranking distance (RD). The presented results reveal that the adapted ANNs created for estimation of soft soils Cc and CR from Brazilian coast and other countries have potential application as an alternative to the empirical correlations, especially during preliminary investigation of suitability of a foundation site during planning stages
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
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
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
(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/9548278358821327; Kripka, Moacir; https://orcid.org/0000-0002-1997-3414; http://lattes.cnpq.br/7554233520986997; Calenzani, Adenilcia Fernanda Groberio; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879
Since the Industrial Revolution started in the XVII century, the emission of greenhouse gases, especially CO2, has increased significantly. In this work, the optimization of a system composed of main and secondary steel and concrete mixed beams and steel pillars was carried out. For the optimization routine, the genetic algorithm and the particle swarm optimization (PSO) were used. For the comparison between the algorithms, three numerical examples taken from works previously published in the literature were modeled. In addition to the numerical examples, a convergence test was modeled in order to verify the confidence of the examples. The results showed a better adaptation of the particle swarm optimization (PSO) compared to the results obtained by the genetic algorithm.
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 DAS ROTAS DE NAVIOS ALIVIADORES PARA RETIRADA DE ÓLEO PRODUZIDO DE PLATAFORMAS OFFSHORE DE PETRÓLEO CONSIDERANDO MÚLTIPLOS COMPARTIMENTOS, MÚLTIPLOS PORTOS E MÚLTIPLAS VIAGENS
(Universidade Federal do Espírito Santo, 2021-03-22) Dias, Jeani dos Santos da Silva; Rosa, Rodrigo de Alvarenga; https://orcid.org/0000-0003-0841-514X; http://lattes.cnpq.br/7706827408886021; https://orcid.org/; http://lattes.cnpq.br/0704476318177045; Resendo, Leandro Colombi; https://orcid.org/0000-0001-7604-2440; http://lattes.cnpq.br/8108487234297364; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
Oil is often produced in locations far from where it will be refined and distributed. In Brazil, most of the oil production occurs in the sea where the oil is stored on platforms until the moment of its transfer to the ports. As the capacity of the oil storage tanks on each platform is limited, it is necessary to adopt some methodology to remove the volume produced to maintain continuous production. The collection of oil produced by ships is one of these methodologies and involves several operational restrictions. Among the restrictions we can mention the type of ship that can dock at each platform and port, the transport capacities of each ship, the need to keep different types of oil separate on the ship, and the initial and final moment to start the withdrawal of oil in each request to remove oil from the platform so that it does not have to stop production if this capacity is fully occupied. The decision of which ships will collect the different types of oils produced by each platform, in which sequence and in which ports the ships will deliver oil, from a series of available ports, make routing difficult. To carry out this planning, a new mathematical model is proposed considering several trips, multiple ports, multiple holds, and the restrictions mentioned to reduce the cost of transportation. 33 instances were created based on the largest Brazilian oil exploration and production company. CPLEX 12.10 was used to solve the model and the reduction in the total cost was up to 17.8% and the decrease in the total distance traveled by the ships was up to 13.3%. The proposed method proved to be applicable to travel planning to meet the service requests of the platforms, as well as a tool to support strategic decisions.
Planejamento de portos graneleiros para atender a produção de usina pelotizadora considerando designação de áreas de pátio e fila de navios
(Universidade Federal do Espírito Santo, 2020-01-21) Braga, Thiago Bordal de Oliveira; Rosa, Rodrigo de Alvarenga; https://orcid.org/; http://lattes.cnpq.br/7706827408886021; https://orcid.org/; http://lattes.cnpq.br/1506132065681712; Resendo, Leandro Colombi; https://orcid.org/0000-0001-7604-2440; http://lattes.cnpq.br/8108487234297364; Alves, Elcio Cassimiro; https://orcid.org/0000-0001-6971-2645; http://lattes.cnpq.br/6509450210637509
One of main raw materials of steel industry is the iron ore pellet which is produced in pelletizing process. Due to its physic-chemical properties, the pellets are used mainly at blast furnace feeding, bringing a higher efficiency in steel production process. The iron ore pellets are produced in batches in a continuous process, and are stored at the bulk port „s stockyard until the times that are loaded into vessels to be delivered to customers. In case of lack of storage area availability, the pelletizing production must be discontinued, generating considerable financial impacts. Thus, the pelletizing planners must plan which stockyard and the position of each batch focusing in have sufficient area to store the pellets lots planned to be produced. At same time, they have to plan the lineup of vessels that will arrive at port and that will withdraw the batches from stockyard allowing areas be released for new batches storage. The objective is always to minimize eventual production stoppages due to lack of storage area. The well-known information by planners is the batches production planning date and vessels estimated time of arrival. For the location planning of cargoes at the stockyard, it is discussed at the literature the nominated Yard Assignment Problem (YAP). Considering the planning of vessels berthing sequencing, it is proposed the berth allocation problem (BAP). Although the wide number of BAP published studies, there is a scarcity of studies that discuss the BAP for bulk ports e even less studies integrating the BAP with YAP for pellets bulk ports. Furthermore, it is important to highlight that most of studies that discuss both problems combined has the focus on vessel quay and in reduce vessels permanence time at port. Unlikely of the others, this study has the objective of minimize the nonattendance of pellets batches production plan, in other words, reduce the time between the planned production time and the time the stockyard was used to receive the pellets batch, as well the time of vessels stay at port. To solve this problem is proposed a mathematical model to define the location of each pellets batch at stockyard in an integrated way to the vessels quay planning aiming to attend the pelletizing production plan and avoid eventual production stoppage due to lack of stockyard area. This study can be applied to other pelletizing companies in the worldwide that have different configurations in their own stockyards and quays. The obtained results indicate that the model has high applicability and can be used as a decision tool at the planning process of pellets production allocation at the stockyard
Planejamento do transporte de maquinistas para atendimento às locomotivas acopladas em trens
(Universidade Federal do Espírito Santo, 2018-08-23) Alves, Rafaela Pianca de Castro; Rosa, Rodrigo de Alvarenga; Alves, Elcio Cassimiro; Mauri, Geraldo Regis; Resendo, Leandro Colombi
To ensure rail transport, several processes are necessary, among them, an important one is the transport of train drivers to work in the locomotives coupled in trains, since it guarantees the availability of a driver to conduct the train. This transport happens because it is necessary to change the driver at the end of his shift by a driver initiating his shift. Thus, it must be provided transportation to the driver from your resting point to the train location and vice versa. Transportation planning should consider the operational and legal requirements of the driver profession. The process of exchanging drivers involves costs related to transport him, number of vehicles needed, and kilometers traveled, and costs related to unproductive hours, generated when the driver is not performing the function of driving the train in the period that includes his work shift. To meet both operational and legal requirements, vehicles must be used, and routes must be drawn to transport the drivers from their resting points to the exchange points or vice versa, at a lower possible transport cost and reducing the number of unproductive hours. To solve the problem mentioned, a mathematical model based on the Dial a Ride Problem (DARP) was proposed. To test the proposed mathematical model, it was applied to the region of the Costa Lacerda Station in Minas Gerais, one of the largest sorting yards of the Vitória-Minas Railroad (EFVM), where approximately 100 train drivers work scale daily. The planning done by the mathematical model achieve better results than the planning realized in an empirical way by the EFVM planners, reducing the costs related to the transport and the unproductive hours.
Redução da emissão de CO2 de lajes mistas de aço e concreto via algoritmos metaheurísticos
(Universidade Federal do Espírito Santo, 2023-08-29) Teixeira, Mariana Oliveira; Calenzani, Adenilcia Fernanda Grobério; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879; https://orcid.org/0000-0002-0774-0269; http://lattes.cnpq.br/8744379264600183; Neves, Francisco de Assis das; https://orcid.org/0000-0003-2735-1751; http://lattes.cnpq.br/1371573987063631; Alencar, Guilherme Santana; https://orcid.org/0000-0001-9822-4229; http://lattes.cnpq.br/8239901885386547; Oliveira, Janaina Pena Soares de; https://orcid.org/0000-0003-1131-0744; http://lattes.cnpq.br/6636717465476684; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509
Steel and concrete composite slabs are structural elements that stand out for their advantages, such as the possibility of construction without shoring, ease of installation, construction speed and reduction of tensile reinforcement in regions of positive moment. However, it is noted that in practice this system still has unexplored potential, such as, for example, not considering of continuity of composite slabs under the supports and not considering additional positive tensile reinforcement to the steel formwork. In addition, as civil construction is one of the main responsible for the emission of CO2 into the atmosphere, researches that seek less polluting structural solutions to the environment are necessary. In this context, this research looking for to present the optimal structural solution, with the lowest CO2 emissions, for the construction of composite steel and concrete slabs, considering simply-supported and continuous spans and the dimensioning in the composite phase. A computer program was developed in the MATLAB® numerical computation and programming platform for the analysis and dimensioning of composite slabs according to ABNT NBR 8800:2008. For the structural optimization, the Particle Swarm and Gray Wolf Algorithms were used. The tool was rightly validated and an analysis of simply-supported and continuous composite slabs composed of three different steel formwork available on the market, varying the thickness of the concrete layer, the thickness of the formwork, the compressive strength of the concrete and the diameter of the tensile reinforcement in the positive and negative moment regions was performed. The results indicate that, when comparing the optimal solutions with those provided by the manufacturers, emissions can be reduced by up to 40% and that the simply-supporting slabs are more efficient than the continuous slabs from an environmental point of view. Additionally, it was verified that the insertion of additional positive reinforcement reduces the emission of CO2 from the slab, as it reduces the consumption of steel in the formwork, which is the material responsible for most of the emissions.
Redução da emissão de co2 de vigas mistas protendidas de aço e concreto via algoritmos metaheurísticos
(Universidade Federal do Espírito Santo, 2023-08-30) Fiorotti, Kamila Madeira; Alves, Elcio Cassimiro; https://orcid.org/0000000169712645; http://lattes.cnpq.br/6509450210637509; https://orcid.org/0009-0007-8283-4533; http://lattes.cnpq.br/1896985595031492; Parente Junior, Evandro; https://orcid.org/0000-0003-0219-1376; http://lattes.cnpq.br/1774654203813780; Calenzani, Adenilcia Fernanda Groberio; https://orcid.org/0000000209369950; http://lattes.cnpq.br/9959808218883879; Rodrigues, Marcos Antonio Campos; http://lattes.cnpq.br/6963345955441105
The use of external prestressing has been increasing in recent decades, mainly in the reinforcement of beams in bridges and viaducts, due to its performance and less interference in the local traffic. ABNT NBR 6118:2014 deals with the application of prestressing in concrete structures, and ABNT NBR 8800:2008 presents the requirements for the design of steel beams as well as composite steel and concrete beams. However, the use of prestressing applied to these types of structures is not addressed by Brazilian technical standards. The present study aims to contribute to filling this gap by formulating the optimization problem of prestressed steel and concrete composite beams with full interaction in pretension and straight cables, to minimize CO2 emissions. The dimensions of the doubly symmetric and monosymmetric profiles, the choice of the steel deck slab, the choice of strength, the dimensions of the concrete slab and the number of prestressing cables were considered as the design variables for the optimization problem. To solve the optimization problem, metaheuristic algorithms, such as the Genetic Algorithm (GA) and the Particle Swarm Algorithm (PSO), were applied to compare the optimized solution. Experimental and numerical problems available in the literature were analyzed in the proposal validation step. A parametric analysis was carried out to identify which geometric patterns most influence the solution, as well as the final emissions. From the analysis, it was concluded that the final emissions are strongly influenced by the shape of the steel of slab and the metallic profileof beam, and that the use of prestressing is more suitable for beams with larger spans. It was also verified that the use of concrete with higher resistance in the slabs is more indicated for beams with larger spans. The final results indicates that the proposed formulation can be used to design more sustainable structures.

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