Navegando por CNPq "CNPQ::ENGENHARIAS::ENGENHARIA CIVIL"

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Acesso aberto (Open Access)
Aderência de armadura em concreto reforçado com fibra de aço
(Universidade Federal do Pará, 2018-02-22) ROSSI, Carlos Rodrigo Costa; OLIVEIRA, Dênio Ramam Carvalho de; http://lattes.cnpq.br/1324105476558186
This work evaluates the influence of steel fibers on the bond between reinforcement and concrete and the behavior of beams subjected to bending stress in the Ultimate Limit State, through an innovative test to compare with RILEM RC6 (1983) standard test. Some of the theoretical models that are willing to represent the bond behavior are prescribed by CEB-FIP (2010), ACI 408R (2003) and NBR 6118 (2014) and by the authors' proposed models: Orangun et al. (1977), Harajli (2009), Shen et al. (2016). In the experimental program will be analyzed steel bars with diameters of 8 mm, 10 mm and 12.5 mm in specimens molded with compressive strength concrete of 30 MPa, varying the length of development in lb; 0.75.lb and 0.5 lb (lb is anchorage length determined by NBR 6118, 2014). The steel fibers used with volumes ranging of 0; 39.25; 78.50 and 117.75kg/m³. There will be 27 beams for the proposed test and 12 cube for the standard Pull-Out Test. The beams were tested at 28 days after concreting, the experimental results were presented and compared with the normative predictions. In the standard test for Vf = 0.5%, increase of tension ≈ 4%, for Vf = 1.0%, increase of tension ≈ 11% and Vf = 1, 5%, increase of tension ≈ 15%. In the proposed test, since there was also variation of length development, the best results were for samples with Vf of 1.5% and with 0.5.lb presented higher tension and load of equivalent rupture. In relation to the theoretical analysis, it was concluded that the prescriptions of Orangun et al. (1977) and ACI 408R (2003) presented results closer to the experimental results, exp/teo ≈ 1, and presented a security level of 75% in the evaluation of security level and dispersion. Therefore, it is feasible to state that lengths developments of smaller CRFA exhibit behavior and performance similar to the lengths developments of reinforced concrete and that the work proposed is efficient for the study of the influence of steel fibers in the bond between reinforcement and concrete.
Acesso aberto (Open Access)
Análise comparativa de modelos digitais de terreno (MDT) como apoio no dimensionamento de projetos de saneamento
(Universidade Federal do Pará, 2018-08-21) MESQUITA, Daniel Alvino; DUARTE, André Augusto Azevedo. Montenegro; http://lattes.cnpq.br/1135221873341973; FERNANDES, Lindemberg Lima; http://lattes.cnpq.br/4641468846318922
In Brazil, when it is a question of information about the terrain relief characteristic, mainly in the North and Northeast regions, there is a lack of planialtimetric data, something that indirectly hinders the management and the planning of the cities, in relation to the design and elaboration of sanitation projects. In this way, it is possible to study methods and techniques that reduce the cost-benefit, highlighting the application of Digital Terrain Models (TDM) for better representation of the terrestrial surface. This work has as main objective the comparison of MDTs elaborated from different techniques, as well as to evaluate the implications of these in the water supply project and in the delimitation of water basin and drainage. The municipal seat of Ipixuna do Pará-Pá was adopted as a study area and two techniques were used to obtain altimetric data, namely: through SRTM images (Shuttle Radar Topographic Mission) and by topographic survey with Total Station. The interpolation kriging method was applied to generate the contour lines, aiming to subsidize the generation of MDT. Despite the good correlation obtained between the two MDTs generated. The Pearson correlation indexes of 0.85, agreement index of 0.97 and the performance index of 0.82 indicated that there is a good correlation between the altimetric data allowing the use of SRTM imaging in engineering projects. However, 72.5% of the points presented SRTM image scores higher than the Total Station altimetric data, with a difference between the 2.06 meter sources, indicating that due to the spatial resolution of the SRTM there is a disagreement in the delimitation of the basins for areas smaller than 1.73 km².
Acesso aberto (Open Access)
Análise computacional do rompimento hipotético da barragem de Tucuruí-PA com o auxílio do software Mike Flood
(Universidade Federal do Pará, 2017-10-10) SANTOS, Marlon Braga dos; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378; SANTOS, Viviane Almeida dos; http://lattes.cnpq.br/1489376127395764
Present work seeks to elaborate flood maps and to perform the flood wave analysis, due to the hypothetical break of the dam of the Tucuruí Hydroelectric Power Plant (Tucuruí HPP), using commercial software MIKE FLOOD. For such purpose, are considered, the overtopping scenario and the total rupture of the Tucuruí HPP concrete dam. Methodology adopted for the research consisted of the collection of technical information regarding the damming, in addition the hydrological study of the areas upstream and downstream of the dam, that are essential for the definition of the input parameters in the computational model to be elaborated. Computational hydrodynamic modeling was carried out in three stages: the first consisted of an one-dimensional analysis in MIKE 11 software; subsequently, with the MIKE 21 software, the triangular calculation mesh was generated for the two-dimensional analysis; and finally, the coupled analysis of the two models previously developed with the MIKE FLOOD software was proceeded. Results indicated areas of flood of up to 84.71 km² for the first one hundred and ten minutes after the rupture gap formation, with a reaction time of approximately eight minutes for the resident population in the urban area of Tucuruí, indicating high potential of loss of human life. It should be noted that the hypothetical floodplain covers residential areas and the commercial center of the city, as well as several urban facilities and public agencies, in addition of one of the most important access roads to the city, BR 422, which restricts the definition of evacuation of the affected population. Thus, it is concluded that the consequences of the rupture of the Tucuruí HPP for the analyzed scenario justify the elaboration of an Emergency Action Plan that guarantees the population security the downstream and that minimizes the economic and environmental impacts resulting from such event.
Acesso aberto (Open Access)
Análise da resistência à punção de sapatas de concreto armado
(Universidade Federal do Pará, 2016-06-07) SANTOS, Douglas Freitas Augusto dos; FERREIRA, Maurício de Pina; http://lattes.cnpq.br/4242041552985485
The footings is a kind of superficial foundation rather employed in construction and is used especially for small projects or when the soil is able to withstand the loads without deforming is exaggerated. Footings can present a brittle fracture mode, called puncture. To avoid this kind of disruption that occurs abruptly, it is possible in the design phase to take some measures, such as increasing the shoe height, reinforcement ratio of bending, the strength of concrete or the ratio a/d. In the literature, was carefully collected with a database 216 and tests analyzed by different standards such as the ACI 318 (2011), CSA A23.3 (2004), EUROCODE 2 (2004) and (2010) and NBR 6118 (2014), with the aim of contributing to a better understanding of the punching footings reinforced concrete Then, it was found that the load capacity ranged last much of a provision to another. Besides confirming that the ratio a/d (ratio of shear span the useful height) influence significantly the resistance to puncture. In the case of the standard EUROCODE 2 (2010), was the finding that the locking effect size decreases the resistance to punching footings, increasing the coefficient of variation with the experimental data. The desing recommendations of their countries are used for sizing the punch, but are mainly empirical rules, that is prepared a series of experimental data. Thus, the experimental results must play or come close to reproducing the reality that the component studied issue will be submitted in the case of footings in the soil. The wide range of test systems raises doubts as to need and reliability by verifying discrepancies between the rules and test systems mainly for the ability to last loads, generating uncertainty as to the suitability of these recommendations.
Acesso aberto (Open Access)
Análise da segurança e saúde do trabalho em canteiros de obras: estudo de caso em uma autarquia federal de ensino superior
(Universidade Federal do Pará, 2016-09-15) LIMA JÚNIOR, Moacir de Souza; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
The research analysed public works buildings, members works in the construction sector has feature live with dangerous activities, being necessary preventive actions implementing practices of occupational health and safety, undertaking construction sites more productive, safe and healthy. In order to identify and propose actions to optimize the control of safety and health at work in the construction sites of public institution, was used the case study as a research methodology that had place the campus of the Federal University of Pará, a federal higher education authority; and that investigated the bidding process, the federal legislation, institutional documents, the conditions of construction sites and interviewed professionals of the institution and of the contractors. Checking evidence of imprudence on the part of contractors and deficiencies in the institution’s practices, which demonstrated that the institution needs, to improve and resize your staff to achieve success in the supervision the construction sites. The research was intended to stimulate the public administration to incorporate current practices demonstrating credibility and objectivity to the occupational safety and health performance in his works, preserving the institution as to the compliance with the current legislation and promote your visibility.
Acesso aberto (Open Access)
Análise da tendência de precipitação e vazão na bacia hidrográfica do Rio Amazonas
(Universidade Federal do Pará, 2022-02-24) DIAS, Luanna Costa; FERNANDES, Lindemberg Lima; http://lattes.cnpq.br/4641468846318922
Studying rainfall and flow trends is important to understand hydrological variability and to determine what has influenced increases or decays. The present study analyzes the trends of the space-time annual series of precipitation (total annual precipitation and maximum annual precipitation) and flow (averages, maximums and minimums) in the Amazon River Basin through non-parametric Mann-Kendall and Sen's tests. Slope for five different periods (1975-2014, 1980-2014, 1985-2014, 1995-2014 and 2000-2014). The results indicate that the series of average flows are increasing in the Amazon Basin for all analyzed periods. In the sub-basins of the right bank of the Amazon River, Tapajós and Madeira, the most recent period (2000-2014) registered the greatest trends of increase in the average annual flow from 1998 (year of strong El Niño) and that reached the largest values already observed. In the maximum flow series, the Óbidos station had an increasing rate of increase for the five periods analyzed for extreme flood events, which directly affect the population residing in these areas. Mean flow decay trends were found at six stations in the Tapajós and Madeira sub-basins. As for precipitation, there are significant trends of increase and decay distributed in several distinct regions of the basin. The stations with the highest positive precipitation trends had a significant increase since 1997, reaching the highest peaks in 2013. The comparison of the magnitude of the trends by the Sen's Slope test shows that there is a behavior of increasing flow rates in the entire Amazon basin and in terms of precipitation there are areas of increase and decrease, that is, precipitation is not the only variable that influences the flows of the Amazon River basin.
Acesso aberto (Open Access)
Análise das causas de aditivos de custo e de prazo em obras públicas de instituições federais de ensino
(Universidade Federal do Pará, 2019-03-19) ALVARENGA, Felipe Campos; MAUÉS, Luiz Maurício Furtado; http://lattes.cnpq.br/7497951647889934
Completing works within the cost and schedule stipulated in the planning phase is a major problem faced by managers in the construction industry. With this, several studies have been carried out around the world to identify the main reasons that lead to noncompliance with the works at the time and cost initially established. The present study aims to analyze the contractual additions made in public works of the Federal Institutions of Education (IFEs) and the main reasons that led to their conclusion. To achieve this goal, statistical tools were used to compare the cost and time changes between the country regions. The data of this work includes public construction projects divided in all the 5 regions of the Country, filtered from the database of the Ministry of Education. A diagnosis was made showing the percentage of additives among the regions and the main justifications of the same ones indicated in a sampling in this database. Statistical techniques such as the Kruskall-Wallis Analysis of Variance and the Mann-Whitney U-Test were used for data analysis and inference. As results, the differences in the distribution of time and cost additives were statistically significant among the regions, with the South and Central-West regions presenting the greatest differences and the North, Northeast and Southeast regions with a statistically similar behavior among them. Of the 2178 projects collected, 69.05% had additives of term and 61.89% of cost. The main factors that affect time and cost of the projects were the inclusions and / or modifications of design and the additions of services. The ways to reduce the incidence of overruns point to the use of Building Information Modeling (BIM) technology, lean construction and greater experience in the management of works.
Acesso aberto (Open Access)
Análise estática e dinâmica de uma ponte ferroviária em concreto armado localizada na Estrada de Ferro Carajás
(Instituto Brasileiro do Concreto, 2010-09) TEIXEIRA, Ritermayer Monteiro; AMADOR, Sandro Diord Rescinho; OLIVEIRA, Dênio Ramam Carvalho de
This work presents results of static and dynamic analysis carried out on 593 m length bridge along Carajás railroad in Maranhão state. The bridge's behavior became important due to some changes over the static and dynamic loads once the future train will be heavier. Thus, a mathematic model was developed using the finite element method basis to evaluate its behavior and "in loco" structural moni- toring to get data as strains and vibrations when the trains go through. Several high precision accelerometers and strains gauges were placed along the slab, beams and columns. Numerical and experimental results are shown and the main conclusions validating the applied methodology are presented as well.
Acesso aberto (Open Access)
Análise mecânica e microestrutural da interação do bambu com o concreto
(Universidade Federal do Pará, 2018-04-03) SALGADO NETO, Francisco de Souza; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
Several materials have been used in construction, steel and concrete being the most used. However, such materials present high production costs and generate great impacts to the environment. The purpose of this research is to analyze the interaction between concrete and bamboo of the species Dendrocalamus giganteus as well as to verify the potential of the annealed wire as a reinforcement of bond between the above-mentioned materials, justified by the search for alternative and renewable materials concomitantly with the defense of sustainability. The experimental schedule is divided into 3 stages: morphological, physical and mechanical characterization of bamboo; concrete dosing; and study of bamboo concrete interaction, analyzing the use of two types of wrapping wire on the bamboo surface as a mechanism of bond reinforcement: single spiral and double spiral, from the determination of the bond strength at 28 days for each case, of the load x displacement behavior and the microstructural analysis of the concrete bamboo interaction. The fixed factors were: compressive strength of the concrete (28 MPa), 200 mm is the length of bonded interface, bamboo sticks with rectangular section of 20 mm x 10 mm. All the results obtained were analyzed by statistical tests and it was verified that the presence of the node and the use of wire increases the bond strength by 42% and at least 25%, respectively.
Acesso aberto (Open Access)
Análise para implementação de usina para reciclagem de resíduos da construção civil em Tucuruí-Pa
(Universidade Federal do Pará, 2018-05-25) SIQUEIRA, Rafaela Ribeiro; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
Civil Construction Waste (RCC), as they are known, is generated in construction, remodeling, repairs, excavation of land for civil works and demolitions. In this context, the work was carried out in the municipality of Tucuruí in the State of Pará, with the objective of evaluating the economic feasibility of implementing a RCC Recycling Plant. Research was carried out to diagnose the management of RCCs by the public authority of the city and it was verified that management does not take place efficiently. Thus, through the collection of information, it was possible to estimate the generation of RCC in Tucuruí, the daily generation is around 1.566,33 m3. Thus, to carry out the economic feasibility analysis, the annual gross revenue was determined, where the costs of implementation of the project and operation were calculated, and from the calculated net values, the cash flow from the Recycling Plant and the investment analysis method was calculated using the Net Present Value (NPV), Internal Rate of Return (IRR) Payback (PB) and the Profitability Index (IL) for the time horizon of 20 years, not considering the inflation. In order to define the Minimum Attractiveness Rate (TMA), a rate of 12% was adopted, since it is close to the SELIC rate for the year 2017, 12.25%. The results show that there is economic and financial feasibility in the implementation of this investment, thus, NPV R $ 1,148,946.06 positive, IRR 14%, PB will be completed in 4.2 years and IL 1.71, demonstrating the economic viability of the project. The estimation of three different scenarios was also done, with 5% increase in gross revenue, 5% increase in expenses and increase in TMA by 15%, thus concluding attractive results for the investment.
Acesso aberto (Open Access)
Aplicação de madeiras amazônicas em elementos de madeira lamelada colada (MLC)
(Universidade Federal do Pará, 2023-03-16) NEVES, Paulo Henrique Lobo; MOUTINHO, Victor Hugo Pereira; http://lattes.cnpq.br/8464600937488553; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
Timber is considered on the world stage as the primary building material of the 21st century. However, for this potential to be actualized, technologies for unfolding and using the raw material, such as Glued Laminated Timber (glulam), need to be disseminated and used in a wider range of species. In this regard, we emphasize that, despite the great existing diversity, only some studies are found to verify the potential use of Amazonian timber in glulam. This way, this paper aims to analyze the gluing of ten species native to the Amazon, namely: Jacaranda sp., Simarouba amara Aubl., Astronomium lecointei, Couratari sp., Cedrela fissilis., Cordia Goeldiana Huber, Hymenaea courbaril., Dipteryx odorata. Euxylophora paraensis., Mezilaurus itauba., and the combination with four different types of adhesives, two structural resistant to moisture and two non-structural, using a shear sample of solid timber as a evidence, with a minimum of 20 repetitions per treatment. Complementary tests such as delamination and static bending were carried out. We verified that for some species there was an adhesive with statistically equal and superior resistance in some combinations compared to the control sample, demonstrating that the studied species have the potential for the production of glulam, as well as for other products that use adhesives.
Acesso aberto (Open Access)
Aplicando concreto de elevada resistência reforçado com fibras de aço na supressão do reforço convencional de vigas em concreto armado de resistência normal
(Universidade Federal do Pará, 2020-01-14) SOUSA, Elielson Oliveira de; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
High strength steel fiber reinforced concrete (HS-SFRC) used as suppression of conventional reinforcement normal strength reinforced concrete beams (NS-RC) has been in the current experimental research. Five 150x300x2700 mm³ size beams were prepared and submitted to four point bending test until failure. The beam reference have been produced without steel fibers (fc = 30.0 MPa), with longitudinal reinforcement ratio (ρl,t = 0.91%), and transverse reinforcement (ρw = 0.11%), representative of practice applications. Four other HS-SFRC beams were produced with fc = 60.0 MPa, ρl,t = 0.39% (≈ 60.0% suppression relative to reference beam), ρw = 0.0 % (100.0% suppression) and fiber consume (Cf) alternating in 45,0,60,0, 75,0 and 90,0 kg/m³. The behavior beams was analyzed from load-displacement and moment-curvature relations. The viability to design HS-SFRC beams with suppression conventional reinforcements was verified based on these results and material characterization tests, exposing equivalent mechanical behavior and some cases higher that of NS-RC beams.
Acesso aberto (Open Access)
Aprendizagem Baseada em Problemas (ABP): identificação das dificuldades docentes para a utilização do método no curso de Engenharia Civil.
(Universidade Federal do Pará, 2019-08-28) SILVA, Sidnei Silva e; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
The technical training of engineering teachers brings with it difficulty in mediating in an educational process way of building knowledge, which negatively influences student training. To minimize such effects, we used the Problem Based Learning (PBL) as an alternative. Therefore, this paper aims to present the difficulties identified in the teacher's perception for the use of the method in the civil engineering course through the construction of an implementation proposal in two disciplines in a public university of Marabá. The research is characterized as action research and was developed in eleven cycles proposed in the disciplines. These problems were built based on the contents offered for these subjects and a technical visit to a teaching institution that uses PBL as a curricular basis. Besides, we used observations of similar studies developed on the use of the PBL method. The results demonstrate the feasibility of using the technique, shown by the good acceptance of both the teacher and the students involved in the research. Besides that, we observed which the students have gotten excellent performance at the end of each discipline. However, some difficulties were found: the cultural elements, the curriculum, and the lack of some teaching skills as factors that can hinder the use of the PBL either by the student or by the teacher himself. From these results we concluded that the studies demonstrate the feasibility of using the method, however, essential elements present in the educational process would need to be enhanced so that the PBL could be fully used within the institution, such as teacher training, or curriculum-related issues could contribute to the development of the topic addressed in this study.
Acesso aberto (Open Access)
A aprendizagem baseada em problemas (ABP): uma aplicação na disciplina “Gestão empresarial” do curso de Engenharia Civil
(Universidade Federal do Pará, 2011-10-25) MACAMBIRA, Paulo Marcelo Fecury; NEVES, Renato Martins das; http://lattes.cnpq.br/6538317425557058
The methodology of Problem-based Learning or PBL, unlike conventional methods of teaching is an approach which uses problems to close the gap between theory and practice in the learning process. In addition to encouraging the construction of knowledge, proposes to contribute to the development of some non-technical professional attributes considered important for the practice of engineering in a society in constant and rapid changes. This work, an action research, experienced and sought to analyze the efficiency of the method during its application in the Business Management course, taught to the students at the penultimate and last semester of undergraduate courses in Civil Engineering. Data for analysis were collected through participant teacher / tutor´s observations and through evaluation reports, in which students were asked about PBL, its advantages and disadvantages and their potential to achieve those goals. In the three case studies, although applied to different classes, show through the students´ reports and through a continuous assessment that the learning occurred as well as the knowledge and the development of some skills and attitudes targeted in the discipline, such as: research capacity, entrepreneurship development, methodological innovation and searching for knowledge. In general, students reacted positively to the BPL. This suggests that its applicability is possible in the contexts studied. The methodology also proved to be a useful tool for professional development for teacher regarding to his practice.
Acesso aberto (Open Access)
Argamassa autonivelante com adição mineral (fíler) de resíduo de beneficiamento de mármore e granito.
(Universidade Federal do Pará, 2019-02-04) CHAVES, Patrícia da Silva; PICANÇO, Marcelo de Souza; http://lattes.cnpq.br/4535052395600357
The process of processing marble and granite rocks generates solid waste along its production chain. These residues have environmental impact potential when not properly managed. The waste produced in the polishing phase of marble and granite slabs can be incorporated into the construction industry as an alternative material for the production of concrete and mortar, contributing to technical performance, economic and environmental viability. In this aspect, this work aims to characterize the marble and granite beneficiation residue (RBMG), in its natural state, and uses it as a self-leveling mortar addition to promote cohesion, similar to the viscosity modifying additive (VMA). For this, a reference mortar was produced, one with addition of RBMG and one with addition of VMA. Where, first, the rheological behavior of the pastes and mortars was analyzed. Then, the mechanical properties, durability and microstructural properties of self-leveling mortars were measured. The results show that the RBMG has no pozzolanic potential. The mortar with RBMG presented optimized mechanical properties and durability in relation to the reference mortar, and similar to the mortar with VMA. The microstructural assay demonstrated that RBMG promoted pore refinement of the cementitious structure, probably due to the granular variation of the particles of the residue, providing greater compactness with the optimization of grain packing. It is concluded that the RBMG can be used as an alternative material to replace the VMA, which is an expensive and difficult to reach product in Belém/PA.
Acesso aberto (Open Access)
Avaliação a suscetibilidade de deslizamento de terra na bacia hidrográfica do Rio Trombetas via lógica fuzzy
(Universidade Federal do Pará, 2018-04-03) VIEIRA, Artur Sales de Abreu; PESSOA, Francisco Carlos Lira; http://lattes.cnpq.br/8031687016215046
The landslides are defined as rapid mass movements, which present a well-defined rupture plane causing considerable social and economic damages worldwide each year. The phenomena of mass instabilisation are conditioned by many factors, such as climate, lithology and rock structures, pedology, morphology, anthropic action and others. Prevention actions such as the effective warning system and the establishment of areas susceptible to these processes are necessary because they can minimise the losses and damages caused by these disasters. In this sense, the objective of this research was to elaborate a map of the susceptibility of the landslide to the Trombetas River basin through fuzzy logic, since the area of study is of great economic interest, mainly to the exploration mineral. We used a Geographic Information System (GIS) environment software and the MATLAB in Mamdani type Fuzzy Inference System (FIS) to develop a qualitative model for predicting susceptibility and critical thresholds of landslide warning scenarios. Seven (7) input parameters were included in the model, characterising the topographic, pedological and environmental conditions. The results showed that in the Trombetas River basin there are areas classified as very low (14.11%), low (47.23%), moderate (35.08%), high (0.20%) and very high (3.39%) susceptibility of the landslide.
Acesso aberto (Open Access)
Avaliação de modelos de inteligência artificial híbridos na estimativa de precipitações
(Universidade Federal do Pará, 2022-03-18) GOMES, Evanice Pinheiro; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
The hydrological analyzes carried out from rainfall in the Amazon are essential due to its importance in climate regulation, regional and global atmospheric circulation. However, in this region, there are limitations related to data series with short periods and many flaws, especially in the daily scale. Despite significant advances in science and technology, practical and accurate predictions have been a major concern due to their complexity. Therefore, several conceptual models, empirical or hybrid, have been tested to forecast rain with greater precision. Among empirical models, those that incorporate artificial intelligence (AI) methods are potentially useful approaches to simulate the precipitation process. Artificial Neural Networks (ANN), as AI models, are able to establish a relationship between historical inputs (rain, flow, etc.) and the desired outputs, through a non-linear function composed of several factors that are adjusted to the observed data, allowing your prediction. Thus, to improve the precipitation analysis, hybrid models were developed, involving Artificial Neural Network (ANN) of the type with Time Delay (TDNN), ELMAN network, Radial Base network (RBF) and Adaptive Neuro-Fuzzy Inference System (ANFIS), coupled with Maximum Overlap Discrete Wavelet (MODWT). Six rainfall gauge station were adopted, which are located in different biomes of the region, and satellite data (CMORPH). Rainfall data were evaluated by seasonal periods (rainy and dry). The results obtained demonstrated that the MODWT-ANFIS model had the best capacity to simulate the daily precipitation of the evaluated rainfall gauge station, even for dry periods, which are known to be more difficult to be simulated in relation to the rainy periods. In this case, data entries lagged by 4 days and 5 days performed better, with Nash values close to 1.0 and root mean square errors below 0.001.
Acesso aberto (Open Access)
Avaliação dos métodos normativos para previsão da resistência à punção de lajes sem armadura de cisalhamento e com conectores de aço
(Universidade Federal do Pará, 2016-06-06) PEREIRA FILHO, Manoel José Mangabeira; FERREIRA, Maurício de Pina; http://lattes.cnpq.br/4242041552985485
This work presents an evaluation of the code provisions of various standards for the punching shear failure load on slab-column connections without shear reinforcement and reinforced with steel connectors. The code provisions evaluated are the ACI 3118 (2014), Eurocode 2 (2004), AC Eurocode 2 (2010), UK NA (2004), DIN NA (2011), EHE (2008), NBR 6118 (2014), ETA 12 / 5404 (2012), an adaptation of the ETA proposed by MUTTONI and BUJNAK (2012) and the fib Model Code 2010 (2011). These code recommendations are evaluated for accuracy, safety and economy through 340 test results in flat slabs without shear reinforcement and 140 results flat slabs reinforced with various types of steel connectors arranged in two databases, and all slabs had centered load. In both databases the performance of recommendations was evaluated from a statistical analysis, dispersion analysis of the results and penalized according to the "Demeter Points Classification" (DPC). In addition to the database with slabs without shear reinforcement analysis, in order to assess the reason for the dispersion of code provisions observed the influence of various parameters (fc, ρ, d, u0/d) in code provisions of punching shear resistance load. For the database with results of slabs reinforced with connectors, beyond the initial analysis, the database was divided into groups according to the failure modes of slab. In all groups was carried out the evaluation of equations for each mode of breakage by means of a statistical analysis, dispersion penalty and analysis of results using the "Demeter Points Classification" (DPC). In all groups were assessed the influence of various parameters in the provisions.
Acesso aberto (Open Access)
O balanço de massa das unidades componentes de uma estação de tratamento de esgoto e a utilização da estatística multivariada como ferramenta de verificação do comportamento físico, químico, bacteriólogico e de metais no esgoto bruto e tratado. Estudo de caso: estação de tratamento de esgoto doméstico – ETE Sideral - Belém - PA
(Universidade Federal do Pará, 2013-10-04) FARIAS, Flavia da Silva; MENDONÇA, Neyson Martins; http://lattes.cnpq.br/7534816053779593
The mass balance of the component units of a wastewater sewage treatment and use of multivariate statistics as a tool for verifying the behavior of raw sewage and treated, was implemented in ETE Sidereal Municipality of Belem do Para in Brazil. This study observed the entire flowchart constituent of the station that is designed to receive a maximum flow of raw sewage of 73 l / s. and now serves a flow of only 1.7 l / so that decreases in 96% of the station was designed, realizing then that today the Sidereal ETE is oversized. In verifying the constituent physical parts of the station there were not in compliance measures that have been suggested in the executive project and were perceived as "in situ". In the mass held for three types of flows: maximum (73 l / s) averaged 43 l / if current 1.7 l / s realized that the decrease in attendance constituent units of the system decreases somewhere around 97.5% the volume to which the components are designed for and found in the Sewage Treatment Station Sidereal. In the characterization of the metals present in the raw sewage treated and it was found that the Principal Component Analysis of the boron (B) (63.5%) and followed by barium (Ba) with (21.9%) justify 84.48% the coefficient of variation that determine how prevalent metal in the influent. In Effluent Boron (B) showed a coefficient of variation of 73.7% which justifies as the main component in the influent of WWTP. In the characterization of metals in the sludge was observed that with a percentage of 98.8% the Barium (Ba) is the main element found. The results obtained with principal component analysis to characterize the physic-chemical and bacteriological analyzes of raw sewage and treated ETE observed that the variable "total COD" is positively related to component BOD and negatively correlated with the Total Alkalinity . Regarding physic-chemical and bacteriological, high levels of BOD, Fecal coliform, TSS and VSS, from the releases of effluents, making present the highest concentrations of organic load remaining.
Acesso aberto (Open Access)
Behavior prediction models and control charts for safety control of concrete dams
(Universidade Federal do Pará, 2012-06) LOPES, Romulo Antonio Chaves; SANTOS, Eurípedes Pinheiro dos; VELOSO, Luís Augusto Conte Mendes
This paper presents a study for improving measurement procedures on concrete dams based on the development of behavior prediction models using multiple regression and control charts. The series of displacements of the TA-2 concrete block crest of the Tucuruí Hydroelectric Power Plant, the largest Brazilian hydroelectric power plant, was taken as an example of application. The methodology that was used generated a behavior prediction model that is in good agreement with the measured displacements. Two types of control charts were tested, both of which identified the change in structural behavior of the block.