Artigos de Revista
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Machine learning approach for pavement performance prediction
In recent years, there has been an increasing interest in the application of machine learning for theprediction of pavement performance. Prediction models are used to predict the future pavementcondition, helping to optimally allocate maintenance and rehabilitation funds. However, few studieshave proposed a systematic approach to the development of machine learning models for pavementperformance prediction. Most of the studies focus on artificial neural networks models that are trainedfor high accuracy, disregarding other suitable machine learning algorithms and neglecting theimportance of models
Ano: 2019
Número Páginas:
1-14pp.
Autor(es): Marcelino, P.; Antunes, M. L.; Fortunato, E.
Revista: International Journal of Pavement Engineering
Editor: Taylor & Francis Online
Keywords: predictive maintenance; international roughness index (IRI); Time series forecasts; Pavement management systems (PMS); Pavement performance models; Machine learning
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Mechanical behavior of inert steel slag ballast for heavy haul rail track: laboratory evaluation
The ballast mechanical behavior is one of most important aspects governing the performance and safety conditionsof railway track lines. Usually comprised of natural crushed rock, the research for alternative ballastmaterials becomes interesting both environmentally and economically. This paper presents a comparison betweenaggregates of steel slag and granite by means of monotonic and cyclic triaxial tests carried out on scaleddown ballast specimens. The monotonic triaxial tests were conducted at three different confining pressures tofailure and to critical state. The long-term cyclic tests (at least 106 cycles) were conducted in two stress pathscompatible with heavy haul loadings. The results showed that the steel slag aggregate has higher values ofstrength parameters compared to the granite aggregate and better long-term deformability behavior, expressedby lower degradation and particle breakage and a faster tendency for stabilization the permanent deformation.
Ano: 2019
Número Páginas:
1-10pp.
Autor(es): Delgado, B.; Fonseca, A.; Fortunato, E.
Revista: Transportation Geotechnics
Editor: Elsevier
Volume:
20.
Keywords: Heavy haul rail track; Triaxial tests; Steel slag ballast; Ballast behavior
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Particle morphology
The ballast railway layer is one of the main applications of crushed rocks in civil engineering. Environmentalconcerns have influenced the use of by-products and recycled materials as alternatives to the exploitation of new quarries. One of the main industrial by-products available near railways is steel furnace slag. Mechanical tests performed by monotonic and cyclic triaxial loading showed that this material can perform better than a granite aggregate traditionally used in the ballast layer. The work presented in this paper intends to be a contribution explaining the influence of the individual particles
Ano: 2019
Número Páginas:
1-10pp.
Autor(es): Delgado, B.; Fonseca, A.; Fortunato, E.
Revista: Environmental Geotechnics
Editor: ICE Publishing
Keywords: Waste management & disposal; Testing & evaluation; Geotechnical engineering
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Smartphone
Railway infrastructure managers run dedicated inspection vehicles to monitor the geometric quality of the track (among other aspects) to detect irregularities and ensure safe running conditions of railway lines, in accordance with specific regulations. Unfortunately, these inspections disturb the normal traffic operation, especially in networks with intense traffic; are generally carried out only a few times per year; and, consequently, do not provide prompt identification of critical situations. Considering the recent developments and cost reduction in sensing capabilities of smartphones, the authors present an approach to use these technologies to perform constant acceleration measurements inside in-service trains to complement the assessment of the structural performance and geometrical degradation of the tracks. Cross-correlation values above 0.85 were obtained between the standard deviations of the longitudinal level and the experimental vertical accelerations measured on-board a passenger train on an 11-km railway stretch. ,e results showed that the approach can be used to identify critical situations that affect the performance of the track, regarding passenger comfort, degradation rates, and risk of derailment. It may comprise a low-cost and crowdsourced complement to the general current practice of track geometric inspection by dedicated vehicles and contribute to an earlier detection of track malfunctions, consequently, to a more efficient maintenance planning and infrastructure management.
Ano: 2019
Número Páginas:
1-14pp.
Autor(es): Paixão, A.; Fortunato, E.; Calçada, R.
Revista: Advances in Civil Engineering
Editor: Hindawi
Volume:
2019.
DOI:
10.1155/2019/1729153
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Comprehensive performance indicators for road pavement condition assessment
The selection and use of technical parameters and performance indicators plays an essential role in thepavement management process. It is known that if more parameters are used, a more accurate evaluationof pavement condition is achieved, improving the choice of maintenance and rehabilitation interventions.However, one of the most expensive activities of the pavement management process is data collection.Accordingly, it is necessary to find a balance between the data collected and the real needs of the process.This paper presents a new approach for the development of pavement condition indicators using a machinelearning algorithm named regularised regression with lasso. The present discussion is supported by a casestudy, which compares the proposed method with current practice for the description of the condition of aPortuguese motorway. The results suggest that the application of machine learning methods can improvethe accuracy of pavement condition indicators when less data are available, contributing to achieve abalance between the needed data and information obtained.
Ano: 2018
Número Páginas:
1433-1445pp..
Autor(es): Marcelino, P.; Antunes, M. L.; Fortunato, E.
Revista: Structure and Infrastructure Engineering
Editor: Taylor & Francis Online
Volume:
14:11.
Keywords: Performance indicators; Regression analysis; Machine learning algorithms; Statistical models; Highway maintenance; Pavement maintenance
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Numerical simulations to improve the use of under sleeper pads at transition zones to railway bridges
Transition zones to bridges and other structures are critical locations in railway tracks that frequently evidencepoor long-term performance. Under sleeper pads (USPs) are reported to reduce ballast degradation and controlthe vertical stiffness of the track, which suggests that USPs can contribute to mitigating the frequent negativeeffects associated with transitions zones. Aiming at understanding in greater depth the influence of USPs on thedynamic behaviour of transition zones and at improving the design of such railway structures, the authors havedeveloped an extensive experimental and numerical study. 3-D FEM models using state-of-the-art numericalapproaches were successfully calibrated and validated using experimental measurements. Simulations supportedprevious findings, highlighting the potential benefit of USPs and pointing to the need to careful designing of theresilient properties of USPs and their arrangement along transition zones, so as to avoid introducing abruptvariations in track vertical stiffness.
Ano: 2018
Número Páginas:
168-182pp.
Autor(es): Paixão, A.; Varandas, J.; Fortunato, E.; Calçada, R.
Revista: Engineering Structures
Editor: Elsevier B.V.
Volume:
164.
Keywords: Train-track interaction; Dynamic analysis; 3-D FEM; Field measurements; Under sleeper pads; Transition zones; Railway track
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Photogrammetry for digital reconstruction of railway ballast particles
Ballast aggregate is a natural material widely used in railway lines. Its mechanical properties and particle geometry are meticulously defined using well-established standards and characterisation procedures. Though extensively validated, these procedures have some limitations: they are operator dependent; only provide major particle dimensions; do not inform on surface colour; nor allow for advanced particle wear analysis or particle-based simulations. This work presents a cost-efficient photogrammetry method for 3D reconstruction of ballast particles, as an alternative to the significantly expensive laser scanning. It produces digital models of equivalent or higher quality, allowing for advanced and automated particle geometry analyses. Particle meshes produced here are shared among researchers.
Ano: 2018
Número Páginas:
963-976pp.
Autor(es): Paixão, A.; Resende, R.; Fortunato, E.
Revista: Construction and Building Materials
Editor: Elsevier B.V.
Volume:
191C.
Keywords: Measurements; 3D reconstruction; 3D digital model; Laser scanning; Physical properties; Particle geometry; Photogrammetry; Aggregate; Railway ballast
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Railway track condition assessment at network level by frequency domain analysis of GPR Data
The railway track system is a crucial infrastructure for the transportation of people and goods in modern societies. With the increase in railway traffic, the availability of the track for monitoring and maintenance purposes is becoming significantly reduced. Therefore, continuous non-destructive monitoring tools for track diagnoses take on even greater importance. In this context, Ground Penetrating Radar (GPR) technique results yield valuable information on track condition, mainly in the identification of the degradation of its physical and mechanical characteristics caused by subsurface malfunctions. Nevertheless, the application of GPR to assess the ballast condition is a challenging task because the material electromagnetic properties are sensitive to both the ballast grading and water content. This work presents a novel approach, fast and practical for surveying and analysing long sections of transport infrastructure, based mainly on expedite frequency domain analysis of the GPR signal. Examples are presented with the identification of track events, ballast interventions and potential locations of malfunctions. The approach, developed to identify changes in the track infrastructure, allows for a user-friendly visualisation of the track condition, even for GPR non-professionals such as railways engineers, and may further be used to correlate with track geometric parameters. It aims to automatically detect sudden variations in the GPR signals, obtained with successive surveys over long stretches of railway lines, thus providing valuable information in asset management activities of infrastructure managers.
Ano: 2018
Número Páginas:
26p.
Autor(es): Fontul, S.; Paixão, A.
Revista: Remote Sensing
Editor: MDPI AG
Volume:
10(4), 559.
Keywords: Network level evaluation; Spectral domain; Railway events; Track geometry; Signal frequency analysis; Railways; Ground Penetrating Radar
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Short soil
The authors present a numerical study on railway track subgrade reinforcement using short soil-binder columns through injection, below the ballast layer. A 3D FEM program developed in MATLAB that considers the dynamic train
Ano: 2018
Número Páginas:
8-16pp.
Autor(es): Francisco, A.; Paixão, A.; Fortunato, E.; Varandas, J.
Revista: Computers and Geotechnics
Editor: Elsevier B.V.
Volume:
98.
Keywords: Train
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A study on the dynamic train-track interaction over cut-fill transitions on buried culverts
Sudden changes in the structural and geotechnical properties of railway tracks along its course are normally associated with subgrade stiffness transitions, differential settlements and, ultimately, hanging sleepers that reduce the performance of the railway system. This paper aims at analysing and quantifying the impact of such situations, particularly cut-fill transitions combined with the presence of culverts, on the train-track system response. A cut-fill transition on a buried culvert is used as case study for which track geometry and stiffness evaluation data were available. A numerical model, considering the coupled train-track interaction, was developed using a 3D FEM dynamic analysis tool that was further improved here with a mixed implicit-explicit time integration scheme. The results suggest that the faster degradation rates typically found at similar locations are mostly related to the development of early permanent deformations in the subgrade layers, rather than to sudden stiffness transitions, which then aggravate the problem by causing important dynamic amplifications in the train-track interaction. Therefore, numerical approaches similar to the one presented herein can be valuable tools for designers and railway infrastructure managers in order to anticipate and mitigate such negative effects at these locations.
Ano: 2017
Número Páginas:
49
Autor(es): Varandas, J.; Paixão, A.; Fortunato, E.
Revista: Computers & Structures
Editor: Elsevier B.V.
Volume:
189.
Keywords: Three-dimensional numerical modelling; Longitudinal level irregularities; Railway track geometric quality; Train-track interaction; Culverts; Railway transition zones
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Comunicações
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Ballast quality assessment using Ground Penetrating Radar data processed in frequency domain
In the transport infrastructures context, the support layers have a fundamental role in the degradation of the trackcondition, both in structural aspects and in terms of fouling of the materials that comprise them. Particularly inthe
Ano: 2019
Autor(es): Paixão, A.; Fontul, S.; Marques, A. M. C.
Revista: Geophysical Research Abstracts
Editor: Copernicus Publications
Volume:
21.
Keywords: Ballast fouling; Ground penetrating radar; Ballast; Railways
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Continuous monitoring and evaluation of railway tracks: proof of concept test
A R&D Project was recently completed in Portugal that aimed at designing, developing and demonstrating the applicability of an innovative and integrated approach to assess the performance and condition of railway tracks. A system prototype was developed and installed on board of a self-propelled railway maintenance vehicle. The system is designed to continuously evaluate the vertical stiffness of the track and to detect disturbances on the wheel and rail dynamic contact interactions. The system is also able to post-process the acquired data taking into account structural aspects of the track. Following the work described in another paper submitted to ICSI 2019, this paper presents the methodology used in this project to process the acquired data and determine the relevant structural railway track parameters, such as railway track verticalstiffness, some geometrical properties of the rails and characteristic resonance frequencies of the vehicle-rail dynamic interaction. It also presents the results obtained from the first test using the prototype on a railway track under regular operation. For this purpose, a section of the track was instrumented with additional on-site equipment to provide data for further system assessment and validation. The instrumented section comprised part of a bridge over Ribeira de São Martinho and the adjacent transition zone, near Alcácer do Sal, in Portugal. The data obtained from this proof of concept test, together with the results gathered from previous phases of this project, suggest that the proposed approach is adequate in this context.
Ano: 2019
Número Páginas:
419
Autor(es): Gil de Morais, P.; Morais, J.; Santos, C.; Paixão, A.; Fortunato, E.; Asseiceiro, F.; Gomes, L.
Revista: Procedia Structural Integrity
Editor: Elsevier
Volume:
17.
Keywords: Instrumentation; Track stiffness; Train-track interaction; railway track performance
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Continuous monitoring and evaluation of railway tracks: system description and assessment
innovative and integrated approach to assess the performance and condition of railway tracks. This approach is also expected to contribute to identify the specific causes of some track performance degradation, namely those that are related to the characteristics of the layers and the geomaterials that compose the substructure of the track. A system prototype was developed and installed on board of a self-propelled railway maintenance vehicle. The system is designed to continuously evaluate the vertical stiffness of the track and to detect disturbances on the dynamic contact interface between the wheelsets and the rails, some of which can be related to defects on the tracks. The system is also able to post-process the acquired data. This paper includes an overall system description of the prototype implemented based on the discussed approach and the first experimental tests performed with said prototype, regarding the system assessment. These tests were performed on a railwayvtrack, adjacent to a maintenance yard. The track was instrumented with additional on-site equipment to serve as reference for thevprototype
Ano: 2019
Número Páginas:
448
Autor(es): Morais, J.; Santos, C.; Gil de Morais, P.; Paixão, A.; Fortunato, E.; Asseiceiro, F.; Gomes, L.
Revista: Procedia Structural Integrity
Editor: Elsevier
Volume:
17.
Keywords: Instrumentation; Track stiffnes; Train-track interaction; Railway track performance
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COURSE
Neste trabalho apresentam-se resultados de um projeto de investigação no âmbito do qual se desenvolveu eaplicou uma abordagem inovadora para avaliação do desempenho da via-férrea, que contribui para identificaras causas das disfunções da via, considerando aspetos relativos à resposta estrutural da interação dinâmica do sistema via-veículo. Descreve-se o sistema protótipo que foi desenvolvido e apresentam-se alguns resultados obtidos, quer no âmbito da calibração laboratorial do sistema, quer num trecho experimental de uma via-férrea em serviço, os quais permitiram validar o método proposto.
Ano: 2019
Número Páginas:
10p.
Autor(es): Fortunato, E.; Paixão, A.; Gil de Morais, P.; Santos, C.; Morais, J.; Asseiceiro, F.; Gomes, L.
Editor: CRP
Keywords: Rigidez; Sistema de medição; Monitorização em contínuo; Via-férrea
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Dynamic analyses on railway track reinforcement with short soil-binder columns
N/A
Ano: 2019
Autor(es): Francisco, A.; Paixão, A.; Varandas, J.; Fortunato, E.
Editor: TRB
Keywords: Train
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Future trends in transport infrastructure monitoring
The intense traffic on existing pavements not only induces increased deterioration but also decreases vailability of pavements for monitoring and maintenance interventions. In Europe, in general, the existing pavement network requires maintenance in order to comply with traffic requirements. In an economic scenario of financial requirements, it is crucial to plan and justify maintenance measures needed for an efficient management. This paper presents future trends in pavement engineering focussing specifically on the non-destructive continuous monitoring, data processing, and possible applications of Building Information Modelling, as improved tools for pavement monitoring and rehabilitation management.
Ano: 2019
Número Páginas:
261-275 pp.
Autor(es): Fontul, S.
Revista: Future trends in civil engineering
Editor: University of Zagreb
Volume:
1.
Keywords: BIM; Structural evaluation; Monitoring; Pavement condition; GPR; FWD
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Improved methods for the imputation of missing data in pavement management systems
Missing data is a common problem in most pavement management systems (PMS) databases, affecting the accuracy of pavement performance predictions and the quality of pavement management decisions. A potential solution to this problem is the imputation of missing values. This study analyses the suitability and performance of four different imputation methods
Ano: 2019
Autor(es): Marcelino, P.; Antunes, M. L.; Fortunato, E.
Editor: Department of Civil Engineering at Liverpool John Moores University
Keywords: Imputation methods; Pavement performance predictions; Pavement management systems; LTPP database; Missing data
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Soil-binder columns for the rehabilitation of railway track platforms
Railway track reinforcement using soil-binder columns without removing track structure can be an efficient method to rehabilitate old lines. This work presents results of a study on a reinforcing method of old railway track platforms with poor bearing conditions. It consists in drilling through the ballast layer and in-jecting binders into the soil to form short columns in the track subgrade. Experimental injection testing has been successful in demonstrating the feasibility of the method, in that it was possible to inject the grout below the ballast layer and to create soil-binder columns with diameters ranging from 30 to 60 cm, depending on the injection parameters, for the different tested soils. The results of the numerical modelling of tested reinforce-ment configurations suggest that the columns provide a reduction of the deviator stress at the top of the plat-form in untreated soil areas between the columns. Therefore, the approach helps to mitigate typical and unde-sirable phenomena of old railway platforms such as progressive shear failure and excessive accumulation of plastic deformation at the ballast-platform interface. To validate the method even further, cyclic loading tests on true scale physical models are currently underway to study the resilient and permanent deformation of rail-way tracks with poor bearing conditions, submitted to the reinforcement method
Ano: 2019
Autor(es): Fortunato, E.; Paixão, A.; Gil de Morais, P.; Santos, C.; Francisco, A.; Asseiceiro, F.; Cruz, J.; Cruz, N.
Editor: International Society of Soil Mechanics and Geotechnical Engineering
Keywords: Soil
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A research project on the reinforcement of old railway track platforms using short soil binder columns
The rehabilitation and construction works for the reinforcement of old railway track platforms is a complex, time-consuming and costly process that often causes significant disturbances to normal train operation (Selig & Waters, 1994). Although different reinforcement approaches have been used in the past (INNOTRACK, 2008; Indraratna et al., 2011; Li et al., 2016), from soil replacement to reinforcement with geosynthetics, only a few allow performing the treatment or applying the reinforcement with minimal hindrance to railway operation. In this context, the reinforcement the track foundation, through injection of binders, without removing the ballast layer or the track components, is of paramount importance. Although this approach is not new, it still poses challenges in terms of railway operation, construction processes and quality assurance. For example, according to Li et al. (2016), slurry injection in the track platform has been used on railways since the 80
Ano: 2018
Número Páginas:
4p.
Autor(es): Fortunato, E.; Paixão, A.; Morais, P.; Santos, Carlos; Francisco, A.; Varandas, J.; Asseiceiro, F.; Cruz, J.; Cruz, N.
Editor: Civil-Comp Press
Volume:
A10.01.
Keywords: Soil
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An integrated monitoring system for continuous evaluation of railway tracks for efficient asset management
The maintenance of railway tracks is one of the aspects of the railway infrastructure managementactivity that most influences the technical and economic performance of this transportationsystem. It is common practice to support the maintenance actions based on themonitoring of the infrastructure condition, for example by carrying out visual inspectionsand using dedicated track inspection vehicles. Despite the fact that this traditional approachto evaluate the track, based on its condition, is quite effective, it does not provide usefulinformation on the causes that lead to such reduction in performance. Consequently, themaintenance tends to be more corrective and less preventive. Considering the limitations ofthe available methods, a R&D project is underway in Portugal aiming at designing, developingand demonstrating the applicability of an innovative and integrated approach to assess theperformance of railway tracks, which is also expected to contribute to identifying the causesof some track malfunctions. In this paper we discuss the relevant aspects of this approachand present preliminary results of the tasks currently underway, namely the design and developmentof the prototype system, including the verification of the measurement chain andits validation in laboratory environment.
Ano: 2018
Número Páginas:
667-673pp.
Autor(es): Santos, Carlos; Morais, P.; Paixão, A.; Fortunato, E.; Asseiceiro, F.; Gomes, L.
Revista: Road and Rail Infrastructure V, Proceedings of the Conference CETRA 2018
Editor: Department of Transportation, Faculty of Civil Engineering, University of Zagreb
Volume:
19.
Keywords: Measurement system; Continuous monitoring; Track stiffness; Railway
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Livros
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Application of a gap-graded asphalt rubber wearing course in the rehabilitation of the pavement of two national road stretches (EN104 and EN105) located in the north of Portugal - Field and laboratory
This case study refers to the first significant experience with asphalt rubber, manufactured by the wetprocess, applied on a full scale rehabilitation project in Portugal. It concerns the application of a gapgradedasphalt rubber wearing course in the rehabilitation of the pavement of National road stretchesEN 104 between Azurara and Trofa and EN 105 between Travagem and Santo Tirso. / O presente caso de estudo refere-se à primeira experiência relevante, em Portugal, na qual seutilizaram misturas com betume modificado com borracha reciclada de pneus na reabilitação deestradas nacionais. Diz respeito, em particular, à aplicação de misturas betuminosas rugosas combetume modificado com borracha em camadas de desgaste, no âmbito da reabilitação do pavimento deum troço da estrada nacional EN 104, entre Azurara e Trofa, e da estrada nacional EN 105, entreTravagem e Santo Tirso.
Ano: 2010
Número Páginas:
23pp.
Autor(es): Batista, F. A.; Antunes, M. L.; Santos, C.
Editor: LNEC
Volume:
NS 122
Keywords: Pt; Laboratory test; National road; Rubber; Recycled materials; Road pavement rehabilitation; Asphalt; In situ test; Asphaltic road pavement
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Application of an open-graded asphalt rubber wearing course in the rehabilitation of the pavement of a stretch of the National Road EN 14 located in the North of Portugal - Field and laboratory case s
This case study refers to a successful application of an asphalt rubber wearing course in the frame ofthe rehabilitation of the pavement of the National Road EN 14 between
Ano: 2010
Número Páginas:
20pp.
Autor(es): Batista, F. A.; Antunes, M. L.
Editor: LNEC
Volume:
NS 123
Keywords: Pt; Laboratory test; In situ test; National road; Rubber; Recycled materials; Road pavement rehabilitation; Asphaltic road pavement; Asphalt
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Application of hot mix asphalt with 20% - 25% reclaimed asphalt in the rehabilitation of the pavement of the motorway A1 between Pombal and Condeixa (Portugal) - Field and laboratory case study
This case study refers to plant hot mix recycling works in the frame of the rehabilitation of a stretch ofthe motorway A1, located in the centre of Portugal.It concerns the use of 20% - 25% of Reclaimed Asphalt in the production of two different asphaltconcrete mixtures for application in binder courses. / O presente caso de estudo refere-se ao fabrico e aplicação de misturas betuminosas recicladas a quenteem central, num troço da auto-estrada A1 localizado no centro do País. Neste caso, foram utilizadas nofabrico de duas misturas diferentes, uma Mistura Betuminosa Densa e um Betão BetuminosoSubjacente à Camada Drenante, respectivamente, cerca de 20 % e 25 % de misturas betuminosasrecuperadas.
Ano: 2010
Número Páginas:
20pp.
Autor(es): Batista, F. A.; Antunes, M. L.
Editor: LNEC
Volume:
NS 119
Keywords: In situ test; Laboratory test; Asphaltic cement road pavement; Recycled materials; Motorway; Road pavement rehabilitation; Hot mix asphalt
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Application of hot mix asphalt with 35% - 40% reclaimed asphalt in the rehabilitation of the pavement of the National road EN 105 between Travagem and Santo Tirso (Portugal) - Field and laboratory cas
This case study refers to the first known application of RAP in the production of hot mix asphaltconcrete in Portugal. It concerns the application of a plant hot mix recycled asphalt concrete as abinder course in a national road stretch located in the North of Portugal. / O presente caso de estudo refere-se à primeira obra realizada em Portugal, na qual se procedeu àreutilização de materiais betuminosos fresados na reabilitação de um pavimento flexível de um trechode uma estrada nacional (EN105), situada no Norte do País. Os materiais fresados foram reciclados emcentral mediante a incorporação de novos materiais, e posteriormente utilizados em camadas deregularização.
Ano: 2010
Número Páginas:
20pp.
Autor(es): Batista, F. A.; Antunes, M. L.
Editor: LNEC
Volume:
NS 118
Keywords: In situ test; Laboratory test; Asphaltic cement road pavement; Recycled materials; National road; Road pavement rehabilitation; Hot mix asphalt
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Cold insitu recycling of the pavement of EN 260 between Serpa and Vila Verde de Ficalho (Portugal) - Field and laboratory case study
This case study refers to an application of cold in situ recycling of an old asphalt pavement usingbitumen emulsion.The rehabilitation works were performed in 2 phases: The first phase consisted in recycling theexisting asphalt and granular layers up to 120 mm deep and application of a slurry surfacing. Thesecond phase consisted in placing an asphalt cold mix binder course and a new slurry surfacing. / O presente caso de estudo refere-se à aplicação de misturas betuminosas recicladas a frio
Ano: 2010
Número Páginas:
20pp.
Autor(es): Antunes, M. L.; Batista, F. A.
Editor: LNEC
Volume:
NS 120
Keywords: Pt; National road; Laboratory test; In situ test; Asphalt binder; Cold mix asphalt; Recycled materials; Road pavement rehabilitation; Asphaltic road pavement; Bitumen emulsion
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Rehabilitation of the IP2 pavement between Barragem do Fratel and EN 118 (Portugal) using cold insitu recycling of existing asphalt layers - Field and laboratory case study
This case study refers to a successful application of cold in situ recycling of asphalt layers from aheavily cracked pavement using bitumen emulsion.A new hot mix asphalt binder course and a new wearing course were placed on the recycled layer. / O presente caso de estudo refere-se a uma aplicação bem sucedida de reciclagem a frio
Ano: 2010
Número Páginas:
20pp.
Autor(es): Antunes, M. L.; Batista, F.A.
Editor: LNEC
Volume:
NS 121
Keywords: Pt; Laboratory test; In situ test; Asphalt binder; Cracked road pavement; Cold mix asphalt; Recycled materials; Road pavement rehabilitation; Asphaltic road pavement; Bitumen emulsion
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Capítulos de Livros
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Case Study of an Inert Steel Aggregate in Road Construction: Characterization and Monitoring of the Structural Behaviour
The use of alternative materials, in particular industrial by-products and waste materials, in the construction oftransport infrastructures and geotechnical works, has been promoted across the world. Nonetheless, considering that, in most situations, the application of some of these materials is fairly recent, little information is available on the long-term performance of the infrastructures in which they were used. This work mentions some characteristics of the Inert Steel Aggregate for Construction (ISAC). It presents some results related to the evolution in the surface characteristics and the structural behaviour of a field trial built on a road section in Portugal. ISAC was used in the embankments and pavement layers. The visual inspection, the results of the mechanical tests performed, and the values of the settlements measured on the surface markings about ten years after the section is open to traffic led to conclude that the pavement in the zone where ISAC was used as a construction material is, in general, in a better condition and presents better structural performance than the adjacent areas built with natural materials. The embankment's maximum settlements in the areas with ISAC were similar to the ones observed in the adjacent areas.
Ano: 2023
Número Páginas:
5p.
Autor(es): Fortunato, E.; Roque, A. J.; Gomes Correia, A.
Revista: Advances in Geoengineering, Geotechnologies, and Geoenvironment for Earth Systems and Sustainable Georesources Management
Editor: Springer
Keywords: Long-term performance; Structural behaviour; Mechanical properties; Inert Steel Aggregate for Construction (ISAC)
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Testing and monitoring in railway tracks
Railway tracks may be perceived as simple physical structures, but in fact they entail a significant level of complexity as refers to the assessment and prediction of their transient and long-term behaviors. These mostly result from the intrinsic characteristics of their components and of the dynamic interaction with the suc-cessive passing trains at different speeds and with different loading characteris-tics. The railway industry
Ano: 2022
Número Páginas:
229-255.
Autor(es): Fortunato, E.; Paixão, A.
Revista: Advances on Testing and Experimentation in Civil Engineering
Editor: Springer
Keywords: Monitoring; Testing, Instrumentation; Railway Tracks
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Modelação numérica avançada do comportamento estrutural de vias-férreas
A via férrea balastrada é uma estrutura relativamente simples, mas exibe um comportamento complexo, nomeadamente devido às distintas solicitações dinâmicas a que está sujeita, e à forma como se comportam e interagem os seus diversos elementos. O método dos elementos finitos é particularmente adequado à análise do funcionamento destas estruturas, possibilitando a modelação das ações e a utilização de modelos constitutivos avançados para os diversos materiais que constituem o sistema, permitindo considerar a variação das características físicas e geométricas no espaço. Neste capítulo descreve-se e demonstra-se a aplicação de uma ferramenta de modelação numérica tridimensional, concebida especificamente para o cálculo da resposta dinâmica da via-férrea, cujo desenvolvimento, ao longo dos últimos anos, tem tido a contribuição dos autores. Para além da apresentação e validação da ferramenta de modelação, são apresentados estudos relativos à análise do comportamento da via em situações particulares.
Ano: 2021
Número Páginas:
1-32.
Autor(es): Fortunato, E.; Paixão, A.; Varandas, J.
Revista: Modelação Matemática em Engenharia de Transportes. A experiência do Departamento de Transportes do LNEC.
Editor: LNEC
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Técnicas de machine learning em sistemas de gestão de pavimentos
A utilização de machine learning tem despertado a curiosidade e o interesse do meio académico e empresarial. Com efeito, a aplicação de machine learning, baseada em técnicas capazes de aprender com os dados, tem sido efetuada com sucesso em diversos contextos. Este sucesso é particularmente evidente nas áreas que utilizam grandes volumes de dados e que procuram obter informação que permita alimentar modelos de previsão.Na área dos Transportes, para além da resolução de questões relacionadas com a mobilidade, é expectável que a aplicação de técnicas de machine learning venha a ser cada vez mais frequente em questões relacionadas com a gestão de infraestruturas, em particular no estabelecimento de modelos de previsão do comportamento.Neste capítulo procura-se evidenciar o potencial da aplicação de machine learning em sistemas de gestão de pavimentos, através da descrição de alguns dos trabalhos desenvolvidos pelos autores neste domínio, essencialmente relacionados com a aplicação de machine learning no desenvolvimento de modelos de previsão do desempenho dos pavimentos, uma das temáticas essenciais dos sistemas de gestão de pavimentos.
Ano: 2021
Número Páginas:
47-70.
Autor(es): Fortunato, E.; Antunes, M. L.; Marcelino, P.
Revista: Modelação Matemática em Engenharia de Transportes. A experiência do Departamento de Transportes do LNEC.
Editor: LNEC
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Análise comparada de um agregado de escória de aciaria como material alternativo para lastro de vias férreas do tipo heavy haul por meio de ensaios triaxiais
Este artigo apresenta uma etapa de uma pesquisa mais abrangente que está em andamento na Universidade do Porto, no âmbito do grupo de pesquisa Construct-Geo, que visa avaliar os aspectos geomecânicos de materiais alternativos para uso como camada de lastro em vias férreas do tipo heavy haul. São apresentados resultados de ensaios triaxiais monotônicos e cíclicos conduzidos em corpos de prova de 150 mm de diâmetro por 300 mm de altura, em escala reduzida numa proporção de 1:2,5 em relação à granulometriade lastro padrão AREMA N. 24. Analisou-se um agregado de escória de aciaria, quimicamente e ambientalmente, inerte comparativamente a um agregado de granito, relativamente à resistência e à deformabilidade. Os ensaios cíclicos foram conduzidos em dois escalões de carga de 500.000 ciclos, sendo cada escalão compatível com o carregamento imposto por vias do tipo heavy haul com, respectivamente,32,5 toneladas/eixo e 40 toneladas/eixo. Os resultados mostraram que o lastro de escória de aciaria apresentou parâmetros de resistência superiores comparativamente ao lastro de granito e um melhor comportamento quanto à deformabilidade, expresso por maiores valores de módulo de resiliência, menoresíndices de quebra e degradação de partículas e uma maior tendência de estabilização das deformações plásticas, fenômeno conhecido como shakedown e que também foi investigado.
Ano: 2019
Número Páginas:
55-70pp..
Autor(es): Delgado, B.; Fonseca, A.; Fortunato, E.; Coelho, D.
Revista: As Engenharias frente a Sociedade, a Economia e o Meio Ambiente 3
Editor: Atena
Volume:
3.
Keywords: Ensaios Triaxiais; Escória de Aciaria; Lastro Ferroviário
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Current state of the use of recycled materials in geotechnical works in Portugal
The reuse of recycled materials in geotechnical works has awakened a growing interest in the last few years in Portugal. A committee (GT-VROG) within the Portuguese Geotechnical Society (SPG) was created recently for analysing the current state of this kind of use and for promoting it nationwide. As part of the activities of the group, a national survey within producers of waste materials and potential users in geotechnical works was carried out, and a national seminar was organised within the framework of the activities of the TC-3 of the ISSMGE, in order to discuss the present situation in the country and the best ways to develop the reuse of this kind of materials in geotechnical applications. The seminar had the participation of representatives of the different entities interested on the subject (producers, users, administration and research centres), as well as of invited foreign specialists from other European countries. Taking advantage of the results of these activities, the current state of the use of recycled materials in geotechnical works in Portugal is briefly presented and analysed next.
Ano: 2007
Autor(es): Fortunato, E.; Santayana, F.
Editor: Taylor & Francis
Keywords: Geotechnical works; Recycled materials
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Teses de Doutoramento
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A New Approach for the Maintenance Management of Transportation Infrastructures using Machine Learning
Transportation infrastructures are vital to our society. These infrastructures naturally tend to deteriorate over time. A set of activities is then required to manage existing assets in accordance with sound management principles. These activities are usually integrated into systems that manage infrastructures according to technical, social and economic aspects. This research aims to examine the potential of applying machine learning techniques to current transportation infrastructure management systems. Machine learning is an application of artificial intelligence enabling systems to automatically learn and improve from experience (data), arriving at solutions not explicitly programmed. Powered by algorithms that can learn from data, machine learning leads to efficient and effective systems that improve over time. Over the last few years, the application of machine learning has transformed several industries and could do so for transportation infrastructure as well.To achieve the research objectives, a set of studies was performed. Each of these studies had a specific objective, the set of which can be expressed as follows: to define combined performance indicators for pavement condition assessment using machine learning; to develop machine learning models for pavement performance prediction; to formulate machine learning solutions to overcome pavement data issues, such as missing data; to integrate machine learning techniques into decision support systems for pavement maintenance management. Together these studies explored the development of machine learning applications for solving some standard pavement management problems, providing insights into the application of machine learning to transportation infrastructure management systems. The studies successfully demonstrated the potential of machine learning applications for pavement management systems. It showed that machine learning is applicable to various transportation asset management problems, such as condition assessment, performance prediction, and decision support, and that it is able to outperform some of the analytical techniques currently used. Overall, this research work finds that machine learning is a promising tool for transportation infrastructure management systems.
Ano: 2020
Autor(es): Marcelino, P.
Keywords: Pavement Management Systems.; Decision Support Systems; Prediction Models;; Machine Learning; Transportation Infrastructure Asset Management
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Transition zones in railway tracks: An experimental and numerical study on the structural behaviour
The railway track continually degrades over its life cycle. This has negative consequences for maintenance and availability of the lines and is particularly evident at locations with abrupt changes in the track
Ano: 2014
Autor(es): Paixão, A.
Keywords: Dynamic train-track interaction; Numerical modelling; Instrumentation and monitoring; Cyclic load triaxial tests; In situ characterisation; Degradation of the track geometric quality; Backfill design and construction; Under sleeper pads; Transition zones; Railway track
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Renovação de plataformas ferroviárias. Estudos relativos à capacidade de carga
Esta dissertação pretende ser um contributo para o desenvolvimento de uma metodologia de abordagem do problema da renovação de plataformas ferroviárias em serviço, em particular no que se refere à avaliação da capacidade de carga e técnicas de reforço. A referida metodologia foi desenvolvida com o objectivo de apoiar os projectos de renovação das vias férreas.Os principais aspectos abordados são os mecanismos que contribuem para a degradação das vias férreas, a caracterização
Ano: 2005
Autor(es): Fortunato, E.
Keywords: Ensaios in situ; Modelação física; Modelação numérica; Ensaios laboratoriais; Renovação de caminho de ferro; Capacidade de carga; Deformabilidade da via férrea; Fundação da via férrea; Balastro; Linha férrea
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Deformações permanentes de misturas betuminosas em pavimentos rodoviários
Nas últimas décadas tem vindo a verificar-se, em Portugal bem como no resto do mundo, umacentuado crescimento do volume de tráfego rodoviário e das cargas transportadas pelos veículospesados. Tem-se observado, igualmente, um aumento das exigências funcionais, relacionadas com asegurança e conforto do utente das infra-estruturas, a par das preocupações de carácter ambiental, oque conduz à necessidade de pavimentos rodoviários cada vez mais resistentes e duráveis.Consequentemente, tem-se vindo a recorrer a soluções de pavimentação que envolvem maioresespessuras de camadas betuminosas o que implica uma maior parcela de contribuição docomportamento deste tipo de materiais no desempenho das estruturas de pavimentos. Daqui decorre,entre outros aspectos, uma crescente preocupação com a deformação permanente deste tipo demateriais. Esta situação é também sentida em diversos países, nomeadamente nos países europeus,no Canadá e nos Estados Unidos da América.O presente trabalho tem como objectivo contribuir para um melhor conhecimento do comportamentoà deformação permanente de misturas betuminosas aplicadas em camadas de desgaste depavimentos rodoviários, possibilitando o estabelecimento de metodologias e de critérios de avaliação,que conduzam à selecção de materiais adequados às exigências actuais. Como principais aspectosabordados referem-se a caracterização do comportamento viscoelástico destes materiais, através daexecução e interpretação de ensaios laboratoriais com aplicação de cargas repetidas, que simulemas condições observadas in situ, e a modelação do comportamento à deformação permanente dasmisturas.É analisado o fenómeno da deformação permanente, bem como a sua forma de manifestação naestrutura do pavimento
Ano: 2002
Autor(es): Freire, A. C.
Keywords: Modelação do comportamento estrutrual; Ensaios de simulação em pista de laboratório; Ensaios decompressão uniaxial estático; Ensaio de compressão uniaxial de cargas repetidas; Modelos reológicos; Comportamento viscoelástico; Deformação permanente; Caracterização laboratorial; Misturas betuminosas
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Relatórios
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The way forward for pavement performance indicators across Europe COST Action 354 Performance Indicators for Road Pavements Final Report
The main objective of the COST Action 354
Ano: 2008
Número Páginas:
72p.
Autor(es): Antunes, M. L.; LITZKA, Johann; LEBEN, Bojan; LA TORRE, Francesca; WENINGER-VYCUDIL, Alfred; KOKOT, Darko; Mladenovic, Goran; BRITTAIN, Stuart; VINER, Helen
Keywords: Performance indicators for road pavements
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MISTURAS BETUMINOSAS DE ALTO MÓDULO Aplicação na Beneficiação da EN 14, entre Chantre e Trofa
N/A
Ano: 2007
Número Páginas:
137pp.
Autor(es): Antunes, M. L.
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COST 334 - Effects of wide tyres and dual tvres task group 3 - Pavement wear effects - Mechanistic approach for rutting - Stage 4
N/A
Ano: 2000
Autor(es): Quaresma, Luis.; Ferreira, P.; Batista, A. L.
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COST 334 - Effects of wide tyres and dual tyres task group 3 - Pavement wear effects - Mechanistic approach for rutting - Stage 2
N/A
Ano: 2000
Autor(es): Quaresma, Luis.; Ferreira, P.; Freire, A. C.; Batista, A. L.
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Informações Científicas e Técnicas
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NOVAS SOLUÇÕES DE SUPERSTRUTURA DE VIA PARA A ALTA VELOCIDADE FERROVIÁRIA - Comparação com a via balastrada tradicional
As crescentes exigências impostas ao transporte ferroviário e a necessidade de o tornar num sistemade transporte mais competitivo, têm levado ao desenvolvimento de novas soluções de via-férrea.Estas novas soluções constituem inovações tecnológicas de via-férrea que diferem da via balastradatradicional na utilização de diferentes materiais e métodos construtivos. Apostam fortemente naredução da necessidade de conservação e renovação da via, o que se traduz na diminuição doscustos associados à sua operação, assim como no aumento da disponibilidade da linha.Assim, estas soluções apresentam uma melhor resposta a velocidades de circulação cada vez maiselevadas e a maiores volumes de tráfego, que tendem a conduzir a maior deterioração da via e aconsequentes maiores custos de conservação e renovação. Em comparação com a via tradicional,estas soluções podem ser mais vantajosas, no que se refere à segurança, a aspectos ambientais, àgestão da operação e a custos globais, quando se considera o ciclo de vida da infra-estrutura.Embora estas tecnologias tenham vindo a ser testadas e aplicadas em alguns países, desde há váriasdécadas, em particular no Japão, só mais recentemente diversos países demonstraram especialinteresse pela sua aplicação. Face a estas vantagens, tem-se verificado actualmente uma crescentetendência para a adopção destas novas soluções, sobretudo para as linhas de alta velocidade,particularmente na Europa e Ásia Oriental.Dentro deste contexto, e tendo em conta a previsível integração de Portugal na Rede Europeia de AltaVelocidade, desenvolveu-se o presente estudo com o objectivo de apresentar diversas soluções devia-férrea que estão disponíveis e compará-las com a solução tradicional de via balastrada.O estudo incide na descrição de concepções de via-férrea não tradicionais, como a via sem balastro ea via de apoio misto, fazendo-se especial referência às principais vantagens e desvantagens da viasem balastro, face à solução tradicional de via balastrada, e à experiência da sua aplicação.Apresenta-se ainda uma síntese da situação actual da aplicação destas novas soluções em paísesque apostaram fortemente nas redes de alta velocidade.Do estudo desenvolvido conclui-se que, para novas linhas de alta velocidade, estas soluções podemser bastante atractivas, como alternativa à via balastrada tradicional.Os autores agradecem a todas as entidades e pessoas a título individual a autorização expressa paraa publicação das ilustrações apresentadas neste estudo, encontrando-se estas devidamentereferenciadas.
Ano: 2009
Autor(es): Paixão, A.; Fortunato, E.
Keywords: Comboios de alta velocidade; Novas tecnologias; Infra-estrutura ferroviária; Via férrea
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Current state of the re-use of waste materials in geotechnical works in Portugal
The reuse of recycled materials in geotechnical works has awakened a growing interest in the last few years in Portugal. A committee (GT-VROG) within the Portuguese Geotechnical Society (SPG) was created recently for analysing the current state of this kind of use and for promoting it nationwide. As part of the activities of the group, a national survey within producers of waste materials and potential users in geotechnical works was carried out, and a national seminar was organised within the framework of the activities of the TC-3 of theISSMGE, in order to discuss the present situation in the country and the best ways to develop the reuse of this kind of materials in geotechnical applications. The seminar had the participation of representatives of the different entities interested on the subject (producers, users, administration and research centres), as well as of invited foreign specialists from other European countries. Taking advantage of the results of these activities, the current state of the use of recycled materials in geotechnical works in Portugal is presented and analysed next.
Ano: 2006
Autor(es): Fortunato, E.; Santayana, F.; Roque, A. J.
Keywords: Recycled waste materials; Reuse of materials; Geotechnical works
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Outros
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ABGER 0/31,5 - Agregados britados de granulometria extensa reciclados
N/A
Ano: 2023
Autor(es): entidade LNEC
Keywords: Documento de aplicação; Reutilização de materiais de construção; Agregados para estradas; Mistura betuminosa; Pavimento rodoviário; Reciclagem de resíduos; Reciclagem de materiais; Agregados de detritos de obras
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Guia para a utilização de misturas betuminosas a frio para a reparação rápida de pavimentos rodoviários
N/A
Ano: 2021
Autor(es): entidade LNEC
Keywords: Especificação; Pavimento rodoviário; Reparação de pavimento rodoviário; Mistura betuminosa a frio
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Agregado Siderúrgico Inerte para Construção (ASIC) - Utilização em misturas betuminosas do tipo AC20 base
N/A
Ano: 2020
Autor(es): entidade LNEC
Keywords: Documento de aplicação; Mistura betuminosa; Siderurgia; Pavimento rodoviário; Agregado
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ABGER 0/31,5 - Agregados britados de granulometria extensa reciclados
N/A
Ano: 2018
Autor(es): entidade LNEC
Keywords: Documento de aplicação; Reutilização de materiais de construção; Agregados para estradas; Mistura betuminosa; Pavimento rodoviário; Reciclagem de resíduos; Reciclagem de materiais; Agregados de detritos de obras
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S&P CARBOPHALT® G - Grelha de fibra de carbono pré-revestida com betume oxidado para reforço de pavimentos
N/A
Ano: 2018
Autor(es): entidade LNEC
Keywords: Documento de aplicação; Betume; Reforço de pavimento; Fibras de carbono; Grelha; Camada do pavimento; Pavimento de aeroporto; Pavimento rodoviário
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S&P GLASPHALT® G - Grelha de fibra de vidro pré-revestida com betume oxidado para reforço de pavimentos
N/A
Ano: 2018
Autor(es): entidade LNEC
Keywords: Documento de aplicação; Betume; Fibras de vidro; Grelha; Camada do pavimento; Pavimento de aeroporto; Pavimento rodoviário; Reforço de pavimento
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Guia para a utilização de agregados reciclados provenientes de misturas betuminosas recuperadas para camadas não ligadas de pavimentos rodoviários
N/A
Ano: 2016
Autor(es): entidade LNEC
Keywords: Especificação; Pavimento rodoviário; Guia; Demolição de obras; Mistura betuminosa; Reciclagem de materiais; Agregados para estradas; Agregados de detritos de obras; Camada do pavimento
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Guia para a utilização de materiais provenientes de resíduos de construção e demolição em caminhos rurais e florestais
N/A
Ano: 2016
Autor(es): entidade LNEC
Keywords: Especificação; Estrada rural; Guia; Reutilização de materiais de construção; Demolição de obras; Detritos de obras; Reciclagem de materiais; Material de construção de estradas; Estrada florestal
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Guia para a utilização de materiais provenientes de resíduos de construção e demolição em preenchimento de valas
N/A
Ano: 2016
Autor(es): entidade LNEC
Keywords: Especificação; Valetas; Guia; Reciclagem de materiais; Demolição de obras; Detritos de obras; Reutilização de materiais de construção
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AEIRU - Agregados artificiais de escórias de incineração de resíduos urbanos para pavimentos rodoviários
N/A
Ano: 2015
Autor(es): entidade LNEC
Keywords: Documento de aplicação; Escória; Agregados para estradas; Resíduo urbano; Incineração de resíduos; Pavimento rodoviário; Reutilização de materiais; Agregados artificiais
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