Trafikverkets drift- och underhållsentreprenader "basunderhåll väg" anses av entreprenörerna ha en obalanserad riskfördel. Huvudfrågan är om totalentreprenad är den bästa lösningen på Trafikverket driftkontrakt på vägsidan. Examensarbetet har utförts tillsammans med NCC. Datainsamlingen har gjorts dels genom litteraturstudier och dels genom intervjuer med Trafikverket, Sveriges Byggindustrier samt de stora entreprenörerna Svevia, NCC, Peab och Skanska. Slutsatsen av arbetet är att kontrakten innehåller för många oklarheter för att upphandlas på totalentreprenad, men får Trafikverket kontroll på mängder som ska utföras framöver är det fullt möjligt att upphandla kontrakten på totalentreprenad. Däremot kommer det inte att hinnas med någon inventering av mängderna inför kommande upphandling. Av den anledningen föreslås att kontrakten 2018 upphandlas som samverkansentreprenad utan incitamentsavtal under de två första åren då entreprenören tillsammans med Trafikverket inventerar och planerar vad som ska utföras under den fyraåriga kontraktstiden. Inför tredje och fjärde året görs ett incitamentsavtal 50/50 när omfattningen är mera känd. / Trafikverket:s Road maintenance contracts, "Basunderhåll väg", is considered by the contractors to have an uneven distribution of risk between the partners. The main question is if Design-build contract is the best solution for Trafikverket:s Road maintenance contracts on the roadside. The essay has been written on behave of NCC account. The study is based upon literature studies, but also by interviewing staff from big companies, whom are affected by these contracts (Trafikverket, Sveriges Byggindustrier, NCC, Svevia, Peab, Skanska). The main conclusion with the essay is that the contracts maintain too many uncertainties to be procured at a Design-build contract. However, if Trafikverket manages to control the amount mass data, it is highly possible to procure contracts with Design-build contract contracts in the near future. Although, it will not be obtainable to have some sort of inventory of these amounts for the upcoming procurements. By this reason, the proposal is Partnering contract procured by 2018 without any incentives during the first two years. Both the contractors and Trafikverket plan the inventory of what shall be done during the four-year contract period. For the third and the final year they shall make an agreement on a target price for the incentive 50/50 when the extent is better known. Key

For the last two decades, the road maintenance concept has been gaining tremendous attention. This has brought about new institutional changes, predominant of which is the challenge for maintenance managers to achieve maximum performance from the existing road system. Such challenge makes it imperative to implement comprehensive systems that measure road maintenance performance. However, the road maintenance performance measurement systems developed and implemented by researchers and state departments of transportation (DOTs) mainly focus on the effectiveness measures, e.g., the level-of-service. Such measurement systems do not sufficiently elaborate on the efficiency concept, e.g., the amount of resources utilized to achieve such level-of-service. Not knowing how "efficient" state DOTs are in being "effective" can lead to excessive and unrealistic maintenance budget expectations. This issue indicates the need for a performance measurement approach that can take the efficiency concept into account. Another important concept that is not investigated in the current road maintenance performance measurement systems is the effect of the environmental factors (e.g., climate, location, and etc.) and operational factors (e.g., traffic, load, design-construction adequacy, and etc.) on the performance of the road maintenance process. This issue, again, indicates the need for a performance measurement approach that can take such external and uncontrollable factors into account. The purpose of this research is to develop and implement a comprehensive framework that can measure the relative efficiency of different road maintenance strategies given the (i) multiple inputs and outputs that characterize the road maintenance process and (ii) uncontrollable factors (e.g., climate, traffic, etc.) that affect the performance of such process. It is challenging to measure the overall efficiency of a process when such process is a multiple input-multiple output process and when such process is affected by multiple factors. To address this challenge, an innovative approach to efficiency measurement, Data Envelopment Analysis, is used in this research. It is believed that this research, by taking the efficiency concept into account, will significantly improve the ways that are currently used to model and measure the performance of road maintenance. The findings of this research will contribute new knowledge to the asset management field in the road maintenance domain by providing a framework that is able to differentiate effective and efficient maintenance strategies from effective and inefficient ones. / Ph. D.

In the late 1980s and early 1990s few transportation agencies around the world considered performance-based specifications as an alternative to improve the efficiency of the services provided to the public. These initiatives are better known as Performance-Based Road Maintenance (PBRM). PBRM calls for performance-based work, in which a desired outcome is specified rather than a material or method. This type of specification promises to be an excellent tool to improve government efficiency in maintaining transportation networks; however, without proper monitoring, it could likely yield adverse outcomes. Since PBRM is relatively new, the availability of reliable and comprehensive sets of guidelines to evaluate the effectiveness and efficiency of this type of specifications in the roadway maintenance arena is limited. Transportation agencies currently rely on criteria and procedures they have had developed from their traditional methods used to evaluate performance. Unfortunately, some of these procedures cannot appropriately assess the benefits, if any, accrued by the government as a result of implementing performance-based specifications for the maintenance of the roadway system. This research presents the development of a framework for monitoring PBRM more comprehensively and accurately. The framework considers the assessment of five main areas -- Level of Service Effectiveness, Cost-Efficiency, Timeliness of Response, Safety Procedures, and Quality of Services -- in order to guarantee the comprehensiveness and reliability of the evaluation process. The major contribution of this framework is to provide transportation agencies with guidelines for evaluating the effectiveness and efficiency of PBRM as an alternative delivery method to maintain and preserve the roadway system. / Ph. D.

Performance based contracting in the transportation arena is a rather recently implemented concept which has a few number of applications in the United States up to date. Nonetheless, the US Department of Transportation has vigorously promoted (by issuing memorandums to be distributed to the Highway Agencies and State Departments of Transportation) the conversion of traditional contracts to performance based contracts to reach a goal of 80% of the service contracts and actions being performance based by the end of fiscal year 2004 (Tomanelli 2003.) Virginia Department of Transportation (VDOT) has been one of the first state agencies that took the initiative of using a performance based contract for the maintenance of a portion of its interstate highway system. This initiative resulted in the establishment of the 'Comprehensive Agreement for Interstate Highway Asset Management Services' between VDOT and a private contractor in 1996 which resulted in the privatization of highway maintenance services. One of the important aspects of this contract related to this research is that it does not encompass any warranty clauses. In other words, the contractor does not provide any warranty to the VDOT for the services it is obligated to undertake. The contract is mute in this subject, making the contractor incur no liability for the underperformance of the maintenance activities. According to this research, this might lead to some cases which VDOT would not be willing to encounter. Just like performance based contracting, the use of warranties in highway contracts in the United States is a quite new concept which mainly dates back to 1995. There are different views possessed by different parties about the possible outcomes of implementing warranties in highway contracts. Nonetheless, this research proposes that the incorporation of warranty clauses into the VDOT issued performance based road maintenance contracts is vital to ensure the quality and durability of the work after the project completion. According to this research, warranty clauses, if developed carefully, give the contractor the motivation to implement superior maintenance practices to improve the overall conditions of the assets during the contract period. This is done in order to lengthen the life of each asset item and achieve the long term performance. Ultimately, the incorporation of warranty clauses is believed to reduce the risk imposed upon VDOT. Within the context of the discussion presented above, this research first illustrates that the complete satisfaction of one of the parties (VDOT) may be in question due to the absence of the warranty clauses within the contract, then lists and explores the benefits that would/may be gained by the incorporation of warranty clauses into the contract, and finally develops a warranty clause template and proposes it to be used in the future performance based road maintenance contracts issued by VDOT. At the bottom line, this study aspires to help the party in question (VDOT) to reduce the risk imposed upon it and to improve the future performance based road maintenance contracts it will issue. This research uses the VDOT contract as a baseline to define the problem and to propose a solution (i.e. the developed warranty clause template) for that. Nonetheless, some of the principles and approaches used during the development of the warranty clause template can also be referred to for the development of warranty clauses for the performance based road maintenance contracts issued by the other state DOTs. / Master of Science

This thesis research has attempted to address two challenging problems in winter road maintenance, namely road surface condition (RSC) estimation and forecasting. For RSC estimation, the goal of the research was to develop models to discriminate RSC classes based on continuous friction measurements (CFM) and other available data such as temperature and precipitation history. A systematic exploratory study was conducted on an extensive field data set to identify the categorical relationship between RSC and various aggregate CFM measures, such as those related to probability distribution and spatial correlation. A new multi-level model structure was designed, under which binary logistic regression models were calibrated and validated utilizing several carefully chosen aggregate measures to classify major RSC types. This model structure was found to be effective in capturing the overlapping nature of CFM ranges over different RSC types -- a problem which has not been addressed adequately in the past studies. An alternative model with support vector machine (SVM) was also developed for benchmarking the performance of the proposed logit model. It was found that the two types of models are comparative in performance, confirming the high performance of the proposed multi-level model. For road surface condition forecasting, a novel conceptual framework for short-term road surface condition forecasting is proposed, under which the short-term changing process of surface temperature, friction level and contaminant layer depths, is comprehensively explored and analyzed. This study framework is designed to consider all important conditional factors, including weather, traffic and maintenance operations. The maintenance operations, especially salting, are handled by loosening the strict Markovian assumption, i.e., a history instead of one single time interval of salting operations is considered. In this way, the variation of snow/ice melting speed caused by both residual salt amounts and salt/contaminant mixing states is incorporated in the forecasting model, which enables accurate short-term forecasting for contaminant layers. This approach practically circumvents a major limitation of previous studies, making the post-salting RSC forecasting more reliable and accurate. Under the proposed model framework, several advanced time series modelling methodologies are introduced into the analysis, which can capture the highly complex interactions between RSC measures and conditional factors simultaneously. Those methodologies, especially the univariate and multivariate ARIMA methods, are for the first time applied to the winter RSC evolution process. The forecasting errors of surface temperature, friction level and contaminant layer depths are all found to be small, implying that both the proposed study framework and the resulting solutions closely match the real-world observations. The proposed forecasting models are simple in structure, easy to interpret and mostly consistent with physical knowledge. Compared to the existing models, the proposed models provide extra flexibility for refactory, tuning and deployment. Furthermore, all the modelled RSC measures are numerical and the forecast errors are relatively small, suggesting empirical models could be an efficient alternative to physical models. With the well-designed modelling methods, the resulting empirical models as calibrated in our study can be implemented into a decision support and simulation tool with high temporal resolution and accuracy.

Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.

FARIAS, Teresa Raquel Lima. Estradas rurais não pavimentadas como fonte de sedimentos em bacia hidrográfica do semiárido. 2016. 97 f. : Tese (doutorado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2016. / Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-08-05T17:12:33Z No. of bitstreams: 1 2016_tese_trlfarias.pdf: 2470558 bytes, checksum: 30335a2cc35e4a28efe3e35816823a1e (MD5) / Approved for entry into archive by guaracy araujo (guaraa3355@gmail.com) on 2016-08-05T17:15:47Z (GMT) No. of bitstreams: 1 2016_tese_trlfarias.pdf: 2470558 bytes, checksum: 30335a2cc35e4a28efe3e35816823a1e (MD5) / Made available in DSpace on 2016-08-05T17:15:47Z (GMT). No. of bitstreams: 1 2016_tese_trlfarias.pdf: 2470558 bytes, checksum: 30335a2cc35e4a28efe3e35816823a1e (MD5) Previous issue date: 2016 / Approximately 80% of the road network in Brazil is unpaved. Studies have reported high erosion rates and runoff produced by the road infrastructure in various parts of the world and report that unpaved roads are significant sources of sediment in river basins. For two years (2013-2014), monitoring in the field under natural rainfall conditions was conducted to characterize runoff and sediment yield of unpaved rural road segments and the respective slopes in semiarid area of the Caatinga biome of northeastern Brazil, vulnerable to desertification. It was assessed the application of modelling in the yield of sediments from road surface. The sediment yield values measured in the years 2013-2014 ranged from 0.30 Mg.ha-1.year-1 to 0.92 Mg.ha-1.year-1, higher than those recorded in the preserved area, but generally lower than those reported in the literature for unpaved roads. However, it is a semiarid area with low rainfall and characterized by low runoff coefficients, which limits the sediment yield and the hydrological connectivity in the area, additionally the two monitoring years coincided with drought in the region. In the monitored road slope segments, sediment yield from the non-vegetated slope was about ten times that of the slope with vegetation. On the road surfaces, the annual sediment yield (normalized by the slope) in a segment with traffic was three times higher than that without traffic, in addition, events occurring after maintenance activities generated sediment concentration peaks as high as 5,000 mg.L-1 in these areas. In the road segment scale, among the models tested for the predicting of sediment yield, the USLE associated with the Maner equation, proved to be a suitable approach, the best results being obtained for the road without traffic due to no interference from external factors, such as traffic and maintenance activities, which are not explained by the model. In the scale of the Benguê catchment (933 km²), where the roads occupy only 0.7% of the surface, the modelling indicated that these areas contributed with approximately 7% of the total soil loss. The results of this study suggest that the sediment yield from roads and slopes with bare surface is at least one order of magnitude higher than those recorded in the preserved areas of the basin. Maintenance activities on roads and traffic of vehicles contribute to the increased availability of sediments and impacting the sediment concentrations, but produce lower impact on the sediment loads, which depend on runoff and the its occurrence after reprofiling of roads. It was also found that the natural vegetation of the semiarid region has potential in capturing sediments in road slopes, with an important role in breaking down connectivity between sediment flows from unpaved roads and the natural drainage system of the catchment. / Aproximadamente 80% da malha viária no Brasil não possui pavimentação. Estudos têm registrado elevadas taxas de erosão e escoamento superficial produzidas pela infraestrutura viária em várias partes do mundo e reportam que estradas não pavimentadas são fontes significativas de sedimentos em bacias hidrográficas. Durante dois anos (2013-2014) foi conduzido monitoramento em campo sob condições de chuva natural para caracterizar escoamento e produção de sedimentos de segmentos de superfície de estradas rurais não pavimentadas e talude viário, em área semiárida do bioma Caatinga do nordeste do Brasil, vulnerável à desertificação. Também avaliou-se a aplicação de modelagem na predição da produção de sedimentos de superfície de estradas. Os valores de produção de sedimentos medidos nos anos de 2013-2014, variaram de 0,30 Mg.ha-1.ano-1 a 0,92 Mg.ha-1.ano-1, superiores aos registrados na área em condição preservada, porém em geral inferiores aos reportados na literatura para estradas não pavimentadas. Entretanto, trata-se de uma área semiárida com baixa pluviometria e caracterizada por baixos valores de coeficiente de escoamento superficial, o que limita a produção de sedimentos e a conectividade hidrológica da área, além de os dois anos de monitoramento terem coincidido com período de seca na região. Nos segmentos de talude rodoviário monitorados, a produção de sedimentos do talude sem vegetação foi cerca de dez vezes superior à do segmento com vegetação. Na superfície de estradas, a produção de sedimentos anual (normalizada pela declividade) em um segmento com trânsito foi três vezes mais elevada que da estrada sem trânsito, além disso, eventos que ocorreram após atividades de manutenção das vias geraram picos de concentração de sedimentos superiores a 5.000 mg.L-1 nessas superfícies. Na escala de segmento de estrada, entre os modelos avaliados para predição da produção de sedimentos, a USLE associada a equação de Maner, mostrou-se uma abordagem adequada, em que os melhores resultados foram obtidos para a estrada sem trânsito, devido a não interferência neste segmento, de fatores externos como trânsito e atividades de manutenção, não explicados pelo modelo. Já na escala da Bacia do Benguê (933 km²), onde as estradas ocupam apenas 0,7% da superfície, a aplicação de modelagem mostrou que estas contribuíram com aproximadamente 7% do total de perdas de solo na área. Os resultados deste estudo sugerem que a produção de sedimentos em estradas e taludes com superfície desnuda é pelo menos uma ordem de magnitude superior àquelas registrada nas áreas preservadas da bacia. Atividades de manutenção nas estradas e o trânsito de veículos contribuem para o aumento da disponibilidade de sedimentos com impacto nos valores de concentração de sedimentos, mas impactando menos as cargas de sedimentos que dependem do escoamento superficial e da ocorrência de eventos após manutenção das vias. Constatou-se que a vegetação natural do semiárido tem potencial na captura de sedimentos em taludes rodoviários, com papel importante na quebra de conectividade entre fluxos de sedimentos provenientes de estradas não pavimentadas e o sistema de drenagem natural da bacia.

Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Aproximadamente 80% da malha viÃria no Brasil nÃo possui pavimentaÃÃo. Estudos tÃm registrado elevadas taxas de erosÃo e escoamento superficial produzidas pela infraestrutura viÃria em vÃrias partes do mundo e reportam que estradas nÃo pavimentadas sÃo fontes significativas de sedimentos em bacias hidrogrÃficas. Durante dois anos (2013-2014) foi conduzido monitoramento em campo sob condiÃÃes de chuva natural para caracterizar escoamento e produÃÃo de sedimentos de segmentos de superfÃcie de estradas rurais nÃo pavimentadas e talude viÃrio, em Ãrea semiÃrida do bioma Caatinga do nordeste do Brasil, vulnerÃvel à desertificaÃÃo. TambÃm avaliou-se a aplicaÃÃo de modelagem na prediÃÃo da produÃÃo de sedimentos de superfÃcie de estradas. Os valores de produÃÃo de sedimentos medidos nos anos de 2013-2014, variaram de 0,30 Mg.ha-1.ano-1 a 0,92 Mg.ha-1.ano-1, superiores aos registrados na Ãrea em condiÃÃo preservada, porÃm em geral inferiores aos reportados na literatura para estradas nÃo pavimentadas. Entretanto, trata-se de uma Ãrea semiÃrida com baixa pluviometria e caracterizada por baixos valores de coeficiente de escoamento superficial, o que limita a produÃÃo de sedimentos e a conectividade hidrolÃgica da Ãrea, alÃm de os dois anos de monitoramento terem coincidido com perÃodo de seca na regiÃo. Nos segmentos de talude rodoviÃrio monitorados, a produÃÃo de sedimentos do talude sem vegetaÃÃo foi cerca de dez vezes superior à do segmento com vegetaÃÃo. Na superfÃcie de estradas, a produÃÃo de sedimentos anual (normalizada pela declividade) em um segmento com trÃnsito foi trÃs vezes mais elevada que da estrada sem trÃnsito, alÃm disso, eventos que ocorreram apÃs atividades de manutenÃÃo das vias geraram picos de concentraÃÃo de sedimentos superiores a 5.000 mg.L-1 nessas superfÃcies. Na escala de segmento de estrada, entre os modelos avaliados para prediÃÃo da produÃÃo de sedimentos, a USLE associada a equaÃÃo de Maner, mostrou-se uma abordagem adequada, em que os melhores resultados foram obtidos para a estrada sem trÃnsito, devido a nÃo interferÃncia neste segmento, de fatores externos como trÃnsito e atividades de manutenÃÃo, nÃo explicados pelo modelo. Jà na escala da Bacia do Benguà (933 kmÂ), onde as estradas ocupam apenas 0,7% da superfÃcie, a aplicaÃÃo de modelagem mostrou que estas contribuÃram com aproximadamente 7% do total de perdas de solo na Ãrea. Os resultados deste estudo sugerem que a produÃÃo de sedimentos em estradas e taludes com superfÃcie desnuda à pelo menos uma ordem de magnitude superior Ãquelas registrada nas Ãreas preservadas da bacia. Atividades de manutenÃÃo nas estradas e o trÃnsito de veÃculos contribuem para o aumento da disponibilidade de sedimentos com impacto nos valores de concentraÃÃo de sedimentos, mas impactando menos as cargas de sedimentos que dependem do escoamento superficial e da ocorrÃncia de eventos apÃs manutenÃÃo das vias. Constatou-se que a vegetaÃÃo natural do semiÃrido tem potencial na captura de sedimentos em taludes rodoviÃrios, com papel importante na quebra de conectividade entre fluxos de sedimentos provenientes de estradas nÃo pavimentadas e o sistema de drenagem natural da bacia. / Approximately 80% of the road network in Brazil is unpaved. Studies have reported high erosion rates and runoff produced by the road infrastructure in various parts of the world and report that unpaved roads are significant sources of sediment in river basins. For two years (2013-2014), monitoring in the field under natural rainfall conditions was conducted to characterize runoff and sediment yield of unpaved rural road segments and the respective slopes in semiarid area of the Caatinga biome of northeastern Brazil, vulnerable to desertification. It was assessed the application of modelling in the yield of sediments from road surface. The sediment yield values measured in the years 2013-2014 ranged from 0.30 Mg.ha-1.year-1 to 0.92 Mg.ha-1.year-1, higher than those recorded in the preserved area, but generally lower than those reported in the literature for unpaved roads. However, it is a semiarid area with low rainfall and characterized by low runoff coefficients, which limits the sediment yield and the hydrological connectivity in the area, additionally the two monitoring years coincided with drought in the region. In the monitored road slope segments, sediment yield from the non-vegetated slope was about ten times that of the slope with vegetation. On the road surfaces, the annual sediment yield (normalized by the slope) in a segment with traffic was three times higher than that without traffic, in addition, events occurring after maintenance activities generated sediment concentration peaks as high as 5,000 mg.L-1 in these areas. In the road segment scale, among the models tested for the predicting of sediment yield, the USLE associated with the Maner equation, proved to be a suitable approach, the best results being obtained for the road without traffic due to no interference from external factors, such as traffic and maintenance activities, which are not explained by the model. In the scale of the Benguà catchment (933 kmÂ), where the roads occupy only 0.7% of the surface, the modelling indicated that these areas contributed with approximately 7% of the total soil loss. The results of this study suggest that the sediment yield from roads and slopes with bare surface is at least one order of magnitude higher than those recorded in the preserved areas of the basin. Maintenance activities on roads and traffic of vehicles contribute to the increased availability of sediments and impacting the sediment concentrations, but produce lower impact on the sediment loads, which depend on runoff and the its occurrence after reprofiling of roads. It was also found that the natural vegetation of the semiarid region has potential in capturing sediments in road slopes, with an important role in breaking down connectivity between sediment flows from unpaved roads and the natural drainage system of the catchment.

Tudo que merece ser mantido e preservado merece ser gerenciado e o gerenciamento da manutenção alcança seu ápice quando tratado na forma de sistema. A sistematização do gerenciamento da manutenção, em que pese ser uma abordagem relativamente recente na ciência e envolver a aproximação dos níveis estratégico e operacionais, é considerada essencial na busca de vantagens competitivas, redução de custos, confiabilidade na produção e prestação de serviços. Desde que as rodovias são consideradas um patrimônio e como tal digno de preservação e gerenciamento, mister que essa gerência da manutenção seja conduzida de forma sistêmica. As rodovias, no caso presente, são as rodovias não pavimentadas localizadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Esse estudo apresenta uma proposta conceitual para a modelagem de um sistema de gerenciamento da manutenção de rodovias não pavimentadas no âmbito de empreendimentos de exploração florestal para extração de celulose. Nesse processo, o estudo tratará de sistemas de gerenciamento da manutenção de rodovias, particularizando os entendimentos de sistemas, gerenciamento e manutenção aplicados às rodovias, assim como apresentará uma visão particularizada da evolução do gerenciamento da manutenção e tratará das abordagens do gerenciamento da manutenção em nível de rede e de projetos. As rodovias não pavimentadas é outro tópico tratado destacando-se as abordagens relacionadas à caracterização e importância dessas rodovias, o conceito de serventia aplicado às rodovias não pavimentadas, os mecanismos de deterioração, modelos de previsão de desempenho e alternativas de manutenção para essas vias, assim como benefícios associados à manutenção, caminhos para priorização seja das intervenções, seja para a seleção das vias, e análises econômicas e financeiras. Outra seção tratará dos empreendimentos florestais de exploração de celulose, oferecendo uma visão geral desses empreendimentos, um panorama do sistema de colheita florestal, trará uma discussão sobre a manutenção de rodovias em empreendimentos privados e as vantagens econômicas de gerenciar a manutenção de redes de rodovias não pavimentada. Todos os conceitos tratados anteriormente são os fundamentos do sistema de gerenciamento da manutenção de rodovias não pavimentadas que se propõe, entre os quais a utilização da ferramenta ‘Relational Unified Process’, uma proposta para condução do processo de gerenciamento da rede não pavimentada, sugestões de políticas e alternativas de intervenções de manutenção, e formas de encaminhamento para a apropriação de dados relativos à frota de veículos e à condição da rede de rodovias. Apresentam-se, ainda, propostas de árvores de decisão para seleção de intervenções de manutenção, conforme a extensão e severidade dos defeitos identificados. / Everything that deserves to be maintained and preserved, deserves to be managed, and the maintenance management reaches its highest level when we deal with it as a system. The systematization of the maintenance management – although it is quite a recent approach as a subject of science that demands putting the strategic and operational levels closer – is considered essential in the search for certain competitive advantages like cost reduction, production pipeline reliability, and service providing. Since roads are viewed as assets worth preserving and managing, such managing has to be carried out in a systemic way. The roads here are the unpaved roads located into forestry exploration entrepreneurship for cellulose extraction. This research presents a conceptual proposal to model an unpaved road maintenance management system located into forestry exploration entrepreneurship for cellulose extraction. This research deals with road maintenance management systems, management and maintenance applied to roads as well as presents a particular point of view related to the evolution of the road maintenance management, and it also deals with the two approaches related to maintenance management, the network-level and the project-level approaches. This work also deals with unpaved roads, characterization and importance of such roads, an approach on the concept of serviceability applied to unpaved roads, mechanisms of deterioration, models to forecast performance, and alternatives of interventions addressed to maintain those roads. It also pinpoints benefits associated with the maintenance, ways to priorize interventions or roads, and some economic and financial analysis. It also works with the forestry exploration entrepreneurship for cellulose extraction, shows a broad vision of that entrepreneurship, approaches the forestry harvesting system, brings a brief discussion about the road maintenance under private entrepreneurships and discusses economic advantages of managing the maintenance of unpaved road network. All concepts previously discussed are the foundation of the proposed unpaved road maintenance management system. Among such concepts is the use of Relational Unified Process tool, a proposal addressed to carry on the unpaved road network management process, suggestions for maintenance polices and alternatives of maintenance interventions, and ways of collecting data related to the vehicle fleet and the condition of the road network. At the end, it presents some decision trees addressed to the selection of maintenance interventions, such trees take into account the length and the severity of the defects identified.