Innovations in design and construction of granular pavements and railways

This paper describes some of the work related with the International Technical Committee TC3 – Geotechnics of Pavements of ISSMGE. For brevity, some topics are selected to be described in some detail, while others are acknowledged for reference purposes. These topics cover: (1) Data Mining tools in transporttation geotechnics showing the capabilities to predict real-value from several attributes and also the possibility to develop a formal updating framework to reduce uncertainty and increase reliability of deformability modulus updating in pavement and rail track structures; (2) Design aspects related with the mechanist approach in the framework of soil mechanics; (3) construction and quality control aspects covering compactor technologies and advanced tools for continuous compaction control and bearing capacity surveys during and after construction. These contributions aim to promote the use of some powerful available tools in the design and construction processes with impacts in the reduction of maintenance costs.International Society for Soil Mechanics & Geotechnical EngineeringThe British Geotechnical Associatio

Introduction for the 1st Proctor Lecture

The Proctor Lecture was first established under the proposal of ISSMGE-TC 202 ‘‘Transportation Geotechnics”, coordinated by Professor António Gomes Correia (2001–2013) and approved at the ISSMGE Board meeting in Paris, September 2013, to commemorate the significant contributions of late Ralph Roscoe Proctor, and to be delivered by the world’s most distinguished achievers in Transportation Geotechnics.info:eu-repo/semantics/publishedVersio

Rapport général du TC202 Géotechnique pour les infrastructures de transport

Today’s needs of urban transportation including roads, railways, airports and harbours demand significant resources for infrastructure development in view of rapid and efficient public and commercial (freight) services. In most cases, authorities have had difficulties in meeting these service demands due to the rapidly growing public, industrial, mining and agricultural sectors in many parts of the world. In order to maximise efficiency and to reduce the costs of maintenance, sound technical knowledge is required. This general report presents major technical advancements around the globe encompassing 33 articles from 19 countries and it is classified into 6 key categories, namely: compaction and subgrade improvement, laboratory testing, theoretical advancements and contributions to design, applications of geosynthetics, numerical modelling and field performance evaluation.De nos jours, les besoins en transports urbains (routes, chemins de fer, aéroports aériens et maritimes) nécessitent d’importantes ressources pour le développement des infrastructures en vue d’assurer des services commerciaux rapides et efficaces. Dans la plupart des cas, en raison de la croissance rapide des secteurs public, industriel, minier et agricole, les autorités se trouvent confrontées à des difficultés pour atteindre les services escomptés. Un savoir technique est alors nécessaire en vue de maximiser l’efficacité et de réduire le coût d’entretien. Le présent rapport général expose les avancées techniques majeures à travers le monde synthétisant 33 articles émanant de 19 pays ; six thèmes clés sont classés : compactage et amélioration des assises, expérimentation en laboratoire, développements théoriques et contributions au dimensionnement, applications des géosynthétiques, modélisations numériques et évaluation des performances sur le terrain.(undefined

Importance of controlling the degree of saturation in soil compaction

n the typical conventional fill compaction, the dry density ρd and the water content w are controlled in relation to (ρd)max and wopt determined by laboratory compaction tests using a representative sample at a certain compaction energy level CEL. Although CEL and actual soil type affect significantly the values of (ρd)max and wopt, they change inevitably in a given earthwork project while CEL in the field may not match the value used in the laboratory compaction tests. Compaction control based on the stiffness of compacted soil in the field has such a drawback that the stiffness drops upon wetting more largely as the degree of saturation, Sr, of compacted soil becomes lower than the optimum degree of saturation (Sr)opt defined as Sr when (ρd)max is obtained for a given CEL. In comparison, the value of (Sr)opt and the ρd/(ρd)max vs. Sr - (Sr)opt relation of compacted soil are rather insensitive to variations in CEL and soil type, while the strength and stiffness of unsoaked and soaked compacted soil is controlled by ρd and “Sr at the end of compaction”. It is proposed to control not only w and ρd but also Sr so that Sr becomes (Sr)opt and ρd becomes large enough to ensue soil properties required in design.Fundação para a Ciência e Tecnologia (FCT)info:eu-repo/semantics/publishedVersio

Evaluation of the stiffness modulus of bituminous mixtures using laboratory tests (NAT) validate by field back-analysis

This paper concerns the evaluation of the stiffness modulus of bituminous mixtures by using the Nottingham Asphalt Tester (NAT). On the basis of indirect tensile laboratory test results, a practical model for stiffness modulus prediction in pavement bearing capacity analysis was established and calibrated for some typical bituminous mixtures used in Portuguese asphalt pavements. Validation of this model was based on two experimental fullscale pavements instrumented du ring construction. To study the bearing capacity of the pavement structure, wheel load tests were carried out with simultaneous instruments measurements. Experimental pavements response modelling during load tests was performed using the finite elements method. The reasonably agreements between the calculated and measured strains indicate that the stiffness modulus prediction method is greatly reliable for the bituminous mixtures tested and could be very useful for further bearing capacity design of asphalt pavements

Determinação do módulo de rigidez de misturas betuminosas aplicadas em estradas da rede rodoviária nacional

Este artigo apresenta o estudo realizado no Departamento de Engenharia Civil e Arquitectura do Instituto Superior Técnico (IST) sobre a utilização do equipamento “Nottingham Asphalt Tester” (NAT) na determinação do módulo de rigidez de misturas betuminosas fabricadas a quente, correntemente aplicadas em estradas da rede rodoviária nacional. Os resultados apresentados referem-se a ensaios de compressão diametral realizados em carotes obtidas em diferentes trechos da rede rodoviária nacional, abrangendo misturas betuminosas aplicadas nas camadas de desgaste, regularização e desgaste. Complementarmente, estudou-se a viabilidade de aplicação dos métodos previsionais mais utilizados correntemente em projecto ao cálculo do módulo de rigidez daquelas misturas betuminosas, através da comparação destes valores analíticos com os obtidos pela via experimental apresentada neste trabalho

Intelligent compaction technology for geomaterials. A demonstration project

Intelligent Compaction (IC), which is a part of Compaction Management, is a real time automatic adjustment and continuous compaction control technology of geomaterials or asphalt layers. The adjustment of the compaction parameters by the equipment is conducted simultaneously to the compaction process, as well as the continuous measurement of a dynamic compaction value, which is an indicator of the material’s degree of compaction. This study seeks to assess the advantages and disadvantages of IC, as well as formulating a comparison with conventional compaction methods in terms of efficiency. This goal was achieved through in situ application of various technologies to two distinct types of material: a soil-rockfill mixture and a sandy soil. Data was obtained and analysed by the IC continuous information, as well as by the application of several different conventional compaction control tests and methods. Results show that the IC technology presents a superior performance, as well as various advantages when compared to conventional compactors.Fundação para a Ciência e a Tecnologia (FCT

Solutions for embankment-bridge transition zones

High speed trains bring new problems due to high speeds and it is easily understood that the quality criteria for high-speed lines must be much more restrictive than those for conventional rail lines to assure comfort and safety of passengers. Transition zones are, nowadays, one of the biggest problems of railways and this is the main concern of this paper.Fundação para a Ciência e a Tecnologia (FCT) - projecto SFRH/BD/39055/200

CEC research activities for the period 2003-2005

The Civil Engineering Research Center of the University of Minho will carry out research at an internationally recognised standard of excellence in the following areas: - Construction Materials, dealing with achieving sustainable materials focussing in durability design, use of eco-efficient materials and techniques for materials repair; - Construction Processes & Management, dealing with construction management, building physics and construction technology focusing on sustainable development and building rehabilitation; - Geotechnics, dealing with properties and modelling of natural ground (soil and rocks) and treated materials, focussing in environmental aspects and structures for transportation infrastructures; - Highways, dealing with pavement materials characterisation, pavement recycling, pavement design and pavement evaluation, both functional and structural; - Hydraulics, dealing with modelling techniques of processes in natural environments and engineered systems and decision support systems for sustainable use of water resources; - Structures, dealing with innovation, safety, strengthening and conservation of structures, focussing in new concrete and masonry structures, FRP, ancient structures and bridges; - Urban and Regional Planning, dealing with land use planning and policy, built environment and urban quality of life, and stressing the evaluation aspects. The management of research is the responsibility of the scientific committee, on which a representative of each group is represented. It is also under the auspicious of the Advisory Committee. The Center provides a core of people with internationally recognised expertise in the areas of Civil Engineering, particularly through PhD programs and post-doctoral training. The dynamism of the staff provides a stimulating atmosphere that will attract research students and professionals assuring excellent academic and technical support of their studies. A financial goal is to attract research funding from industry and other National and European research grants to continue its operation at an excellence research level.Fundação para a Ciência e a Tecnologia (FCT

Influence of the particle size distribution on the stifness of granitic materials

A presente comunicação apresenta a avaliação das características de deformabilidade obtidas com recurso a um equipamento triaxial de precisão, sobre três granulometrias diferentes da mesma origem geológica (formação granítica), a saber: uma areia siltosa (D50=0.36mm) designada de Areia de Perafita, e dois agregados graníticos, um (0/12.5) e outro (0/31.5). Os ensaios foram realizados sobre provetes reconstituídos por compactação sobre amostras no estado não saturado, tendo-se procedido à medição das pressões intersticiais negativas, de modo a se poderem também analisar os resultados em termos de tensões efectivas. Os resultados obtidos evidenciaram, para um determinado nível de tensão, um aumento do módulo de deformabilidade (normalizado para o mesmo índice de vazios) com a diminuição da dimensão máxima das partículas.In this paper is presented the stiffness of three materials with the same geological origin, a silty sand designed Perafita sand (D50=0.36mm) and two granite aggregates, one (0/12.5) and another (0/31.5). The stiffness of the compacted materials was studied by means of precision triaxial tests. The influence of non-saturation into the stiffness is also studied through triaxial tests with measurements of negative pore water pressures. Such measurements allow the analysis of the mechanical behaviour of the unsaturated materials in terms of effective stresses. The results obtained show, for a certain stress level, an increasing of the Young’s modulus (normalised for a certain void ratio) with the decreasing of the maximum size of particles.GRICES/CNRS – projecto “Security of road and railway infrastructures versus climatic changes