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

Assessment of layer thickness and uniformity in railway embankments with Ground Penetrating Radar

In the aim of a national research project entitled “Interaction soil-rail track for high speed trains”, a protocol was established between the National Railway Network and four national research institutions to develop the knowledge concerning the methodology for the construction and quality control of the railway embankments and railtrack layers for high speed trains. One of the objectives of this protocol is to establish a methodology for quality control of construction layers by different available test methods. Nondestructive testing (NDT) methods are currently very attractive due to their ability to provide information about layer thickness and state condition without causing damage or requiring the removal of material samples. Within the NDT available, ground penetrating radar (GPR) is a very fast and reliable technique, whose advantage is the repeatability and the capability of acquiring continuous data. To reach the proposed goal, a trial embankment was constructed with different materials, layer’s thicknesses, water contents and compaction energy levels. GPR was used in two embankments, in order to detect the thickness of the sub-ballast layer located over the compacted sand layer and its uniformity along the track, but also along the cross-section of the track. In order to control some parameters of the sub-ballast layer, like thickness and uniformity, several metallic plates had been used in the base of the sub-ballast layer, along an alignment. It shows clearly the ability of GPR to detect the sub-ballast layer and its thickness variations along the profile

From Secure Messaging to Secure Collaboration

© 2018, Springer Nature Switzerland AG. We examine the security of collaboration systems, where several users access and contribute to some shared resource, document, or database. To protect such systems against malicious servers, we can build upon existing secure messaging protocols that provide end-to-end security. However, if we want to ensure the consistency of the shared data in the presence of malicious users, we require features that are not available in existing messaging protocols. We investigate the protocol failures that may arise when a new collaborator is added to a group, and discuss approaches for enforcing the integrity of the shared data

Systematisation of seismic retrofitting in vernacular architecture

This paper aims to identify and to systematize the data obtained during the working process of the research project 'SEISMIC-V –Vernacular Seismic Culture in Portugal' in terms of seismic- retrofitting elements earthquake -resistant reinforcement implemented in vernacular buildings. The data will be distinguished based on the structural seismic strengthening and according to the following criteria: strengthening elements, perimeter seismic-resistant elements, arches reinforcing elements, and combined reinforcing elements.Portuguese Science and Technology Foundation (FCT) to the research project ‘SEISMIC - V – Vernacular Seismic Culture in Portu gal’ (PTDC/ATP - AQI/ 3934/2012

Effect of distinct environmental actions on the durability of RC slabs strengthened with prestressed CFRP laminate strips

In the context of concrete structures strengthening, the externally bonded reinforcement (EBR) technique is the most widely used strategy. By prestressing the FRP materials attached to the concrete substrate, the ad-vantages of external prestressing and of the EBR technique are combined. The present work investigates the durability of reinforced concrete (RC) slabs strengthened with prestressed CFRP strips according the EBR technique. Two different anchorage systems were studied: (i) the Mechanical Anchorage (MA) and (ii) Gradi-ent Anchorage (GA). The durability of the specimens was evaluated by exposing them to one out of four envi-ronmental conditions, this combined with a sustained load of 1/3 of the ultimate load for a period of 8 months. Finally, the slabs were monotonically tested up to failure by using a four-point bending test configuration. This work presents the general description of the experimental program, the analysis of the main results, as well as retained conclusions.(undefined

Systematisation of seismic mitigation planning at urban scale

This chapter explores the relation between the seismic mitigation planning that was developed to contribute to minimise effects at urban scale, which arise within the seismic impact. In this sense, it deepens the notion that interdependence, solidarity and cohesion of the different morphological constituents promote a better prepared built fabric, when facing catastrophic phenomena of seismic origin. Preventive approaches and reactive measures arising from the testimony of earthquake-resistant culture in Portugal are also mentioned. From the recognition of the importance of local know-how, infers a set of logical that evidence conditions to transcend the respective vernacular context, making it possible to generically systematize them.Portuguese Science and Technology Foundation (FCT) to the research project ‘SEISMIC-V – Vernacular Seismic Culture in Portugal’ (PTDC/ATPAQI/ 3934/2012

Efeito de distintas condições ambientes na durabilidade de lajes de betão armado reforçadas com laminados de CFRP pré-esforçados

No contexto da reabilitação de estruturas de betão armado (BA) com materiais FRP (Fiber Reinforced Polimers), a técnica EBR (Externally Bonded Reinforcement) é habitualmente utilizada para aumentar a resistência à flexão. A utilização de pré-esforço em sistemas EBR-FRP combina os benefícios da técnica EBR com as vantagens associadas ao pré-esforço externo. O presente trabalho tem como objetivo contribuir para o aumento do conhecimento na durabilidade de lajes de BA reforçadas com laminados de CFRP (Carbon FRP) pré-esforçados segundo a técnica EBR, de modo a colmatar algumas lacunas relevantes que existem sobre este assunto. Neste contexto, dois sistemas de ancoragem foram estudados: (i) a ancoragem mecânica (MA – Mechanical Anchorage) e (ii) o método do gradiente da força (GA – Gradiente Anchorage). Foi estudado o efeito das seguintes condições ambientais na resposta estrutural das lajes: (i) imersão em água; (ii) imersão em água com cloretos; (iii) ciclos de molhagem/secagem em água; para além destas condições ambientais foram ainda utilizadas lajes de referência (iv). O programa experimental de ensaios de envelhecimento acelerado incluiu 16 lajes, nas quais, metade para além da condição ambiental foi também submetida a uma carga gravítica (cerca de 1/3 da capacidade máxima) durante um período de oito meses. No final da aplicação das distintas condições ambientais, as lajes foram ensaiadas monotonicamente até à rotura segundo uma configuração de ensaio de quatro pontos de carga. Este artigo faz uma descrição geral do programa experimental realizado e apresenta uma análise dos correspondentes resultadosEDER através do Programa Operacional Fatores de Competividade – COMPETE e fundos nacionais, através da FCT – Fundação para a Ciência e Tecnologia sob o projeto FRPreDur - FCOMP-01-0124-FEDER-028865 (PTDC/ECM-EST/2424/2012). Este trabalho é também cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do Programa Operacional Fatores de Competitividade e internacionalização (POCI) e do Programa Regional de Lisboa no âmbito dos projetos FRPLongDur POCI-01-0145-FEDER-016900 (PTDC/ECM- EST/1282/2014) e POCI-01-0145-FEDER-00763. S&P Clever Reinforcement Ibérica Lda., S&P Clever Reinforcement Company (Switzerland), Tecnipor - Gomes & Taveira Lda., Vialam – Indústrias Metalúrgicas e Metalomecânicas, Lda., Hilti Portugal - Produtos e Serviços, Lda

RESOLUÇÃO DE PROBLEMAS DE VIGA HIPERESTÁTICA APOIADA SOBRE CINCO APOIOS ATRAVÉS DO SOFTWARE SCILAB

Há algum tempo atrás, antes do desenvolvimento dos softwares todos os cálculos numéricos em um projeto eram realizados manualmente pelo engenheiro responsável através de um processo extenso e trabalhoso com relativa possibilidade de erro. O desenvolvimento de software específicos, trouxe uma sensível melhora na qualidade dos cálculos e maior precisão nos resultados, permitindo ao engenheiro dedicar maior tempo à compreensão dos aspectos físicos dos problemas de engenharia. O presente trabalho tem como objetivo a resolução de problemas de mecânica das estruturas através de uma lógica de programação transferidos para a linguagem do software Scilab, tendo como resultado as reações de apoios, momentos em nós internos e momentos máximos em vãos, para o caso de vigas contínuas hiperestáticas sob cinco apoios pelo Método dos Deslocamentos. Para a comprovação do método são propostos três exemplos, onde são comparados e confirmados com os resultados do software Ftool

Identification of Saccharomyces cerevisiae genes involved in the resistance to multiple stresses during Very-High-Gravity and lignocellulosic biomass industrial fermentations

Most of the current processes for bioethanol production are based on the use of Very-High-Gravity (VHG) technology and the processing of lignocellulosic biomass, limited by the high osmotic pressure and ethanol concentration in the fermentation medium, and by inhibitors resulting from biomass pre-treatments, respectively. Aiming the optimization of strains for industrial bioethanol production an integrated approach was undertaken to identify genes required for simultaneous yeast resistance to different fermentation-related stresses. The integration of previous chemogenomics data was used to identify eight genes whose expression confers simultaneous resistance to high concentrations of glucose, acetic acid and ethanol, chemical stresses relevant for VHG fermentations; and eleven genes conferring simultaneous resistance to different inhibitors present during lignocellulosic fermentations. The expression of BUD31 and HPR1 lead to the increase of both ethanol yield and fermentation rate, while PHO85, VRP1 and YGL024w expression is required for maximal ethanol production in VHG fermentations. Five genes, ERG2, PRS3, RAV1, RPB4 and VMA8 were found to contribute to the maintenance of cell viability in wheat straw hydrolysate and/or for maximal fermentation rate of this substrate [1]. Moreover, the yeast disruptome was screened for strains with increased susceptibility to inhibitory compounds present in an industrial lignocellulosic hydrolysate obtained from wheat straw. With this genome-wide analysis, 42 determinants of resistance to inhibitors were identified showing a high susceptibility phenotype compared to the parental strain. The identified genes stand as preferential targets for genetic engineering manipulation to generate more robust and efficient industrial strains