Orientador: Newton de Oliveira Pinto Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-08T03:07:34Z (GMT). No. of bitstreams: 1 Fernandes_Andrea_M.pdf: 3789790 bytes, checksum: 3995163d23effcb84c04682718a55ef9 (MD5) Previous issue date: 2005 / Resumo: O reforço do concreto através da utilização de fibras de aço vem se mostrando, ao longo dos anos, como alternativa econômica e tecnicamente viável para diversos tipos de aplicações . Sua ampla utilização na indústria da construção mundial, em diversos casos de sucesso, despertou interesse também do segmento tuneleiro moderno. Passou-se a utilizar fibras para reforçar o concreto das aduelas dos anéis montados por tuneladoras (TBM- Tunnel Boring Machines ¿ máquina de escavar túneis) nas principais obras ao redor mundo. Desta forma, após diversos anos sem obras importantes de túneis metroviários no Brasil, a construção da linha 4 (Amarela) do Metrô de São Paulo, utilizará uma destas máquinas de escavar túneis, sendo do tipo EPBM (Earth Pressure Balanced Machine), cujo revestimento será feito com anéis segmentados (aduelas) de concreto. O projeto básico desta obra (década de 60) prevê armação das aduelas de forma tradicional (em desuso) com gaiolas de aço. Em virtude dos benefícios que o reforço com fibras oferece, e ainda, baseando-se no sucesso da experiência mundial, surgiu a necessidade de um estudo no Brasil sobre esta tecnologia. Assim, tomando como base os dados do projeto básico do projeto da linha 4 (cargas, geometrias, etc.), iniciou-se um estudo comparativo do reforço com gaiolas e do reforço com fibras de aço. Este trabalho apresenta algumas etapas deste estudo, procura abordar aspectos relevantes do processo desde a fabricação até a instalação das aduelas no túnel, explica os benefícios possíveis de serem atingidos, resume alguns dos principais motivos que levaram a indústria tuneleira a adotar a tecnologia de reforço com fibras de aço, vantagens e desvantagens / Abstract: The reinforcement of the concrete using steel fibers became possible, through the years, by it¿s economical and technical viability. It¿s wide range of utilization in civil construction, in several success work cases, made the modern tunneling industry realize the necessity of studding it as well. Concrete Segmental Lining Rings placed by TBMs - Tunnel Boring Machines - have been produced with Steel Fiber in the ultimate reference jobs around the world. After several years without of Metro projects in São Paulo Brasil, the already under construction line 4 with total 12,8 km of tunnels, will use one EPBM - Earth Pressure Balanced Machine ¿ witch lining is being considered made by reinforced concrete. The Basic Project (from the 60¿s) primarily considered steel bars as cage reinforcement. To benefit from the steel fiber reinforcement concrete, still, based on successful practical cases world wide, became the necessity to study this technology locally, in Brasil. Thus, taking the basic data from the original Line 4 project (geometry, etc.) a comparative study between steel cages and steel fibers started. This work contents some of the steps from this study and intents to evaluate key aspects from the whole process, since production phase at the segment plant, transport, installation and maintenance of the tunnel. Also explains the basic reasons of migration to the steel fiber reinforcement, including the benefits for the whole tunneling industry and society / Mestrado / Edificações / Mestre em Engenharia Civil

De nos jours la quasi-totalité des grandes métropoles du monde comptent avec des réseaux de transport étendus et ont pour la plupart satisfait leurs besoins de construction d’ouvrages souterrains. Cependant le parc des ouvrages existants est vieillissant et une part importante est en service depuis plusieurs décennies, par conséquence, l’entretien et la pérennisation des infrastructures souterraines existantes un enjeu majeur pour la gestion et le développement des villes. En vue d’améliorer leur politique de maintenance, c’est-à-dire pérenniser leur patrimoine et le maintenir dans de bonnes conditions de sécurité et d’exploitation, il est nécessaire que les gestionnaires d’ouvrages puissent mettre à jour leurs techniques de diagnostic (AFTES, 2005). Il est donc impératif de disposer d’outils leur permettant de mieux évaluer l’état réel des ouvrages. Or les méthodes dont disposent à l’heure actuelle les gestionnaires sont le plus souvent soit insuffisantes pour apporter une information quantitative de qualité, soit mal adaptées aux contraintes de ces ouvrages. Dans ce contexte, le projet ANR MéDiTOSS « Méthodologie de Diagnostic des Tunnels et Ouvrages Souterrains en Service » vise à développer une nouvelle méthodologie de diagnostic adaptée à ce type d’ouvrage en caractérisant les différents composants de l’ouvrage (structure du revêtement, terrain encaissant ainsi que leur interface ou contact). L’objectif de cette thèse est de fournir au gestionnaire des indicateurs physiques et mécaniques lui permettant d’orienter sa politique de maintenance en s’appuyant sur une expertise plus certaine. / Maintenance and sustainability of underground structures are the major tasks for infrastructures’ owners. To carry out these tasks, managers need to qualify the actual state of these facilities. There are very few operational methods to describe separately each component of an underground structure (structure lining, contact interface and surrounding soil). Most of them are mainly based on visual inspection. Nevertheless only the intrados of the tunnel is open to visual inspection. To improve their maintenance policy, that is to say sustain their heritage and keep it in good conditions of safety and operational, it is necessary that manager’s can update their diagnosis methods (AFTES, 2005). It is therefore imperative to have tools to better assess the actual condition of structures. However, the methods available at present managers are often either insufficient to provide quantitative information quality or poorly adapted to the constraints of these works. In this context, the ANR project MéDiTOSS "Methodology Diagnostic Tunnels and Underground Structures in Service" aims to develop a new diagnostic methodology adapted to this type of work characterizing the various components of the structure (structure of the lining, enclosing soil and their interface or contact). The objective of this thesis is to provide to the managers of physical and mechanical indicators that will guide its maintenance policy based on a certain expertise.

The diploma thesis deals with the issue of waterproof concrete and testing its properties. The theoretical part is conceived through research on existing knowledge relating to waterproof concrete. Emphasis is placed on the possibility of using a waterproof concrete for structures, such is e.g. tunnel lining. The experimental part is focused on the laboratory testing of waterproof concrete. Particulary examined was the effect of various admixtures as a partial replacement of cement. Monitored was the development of compressive strength and flexural strength, development of temperature during hydration in the early stages of maturation of concrete, water resistance of concrete, concrete surface resistance to water and chemical de-icing agents, as well as development of shrinkage during concrete maturation.

The diploma thesis engages in the reconstruction of railway tunnel Domasovsky that is situated at the track section Olomouc – Krnov. It illustrates the current state of the construction and the geotechnical conditons of the area of interest, it also presents the potencial solutions. The design is verified by stuructural analysis, the design documentation and technical report are also enclosed.

L’Agence nationale pour la gestion des déchets radioactifs (l’Andra) en France propose un nouveau type de voussoirs de tunnel pour les ouvrages très profonds. Pour éviter des segments de tunnel trop épais, ils proposent d’intégrer une couche de matériau granulaire sur l’extrados d’un voussoir moins épais. Cette approche prétend utiliser la grande compressilibité de la couche granulaire constituée de particules broyables et les transferts de charge interne au matériau granulaire pour réduire l’épaisseur du voussoir tout en gardant des performances mécaniques importantes. Un segment de tunnel avec une telle conception est appelé un VMC monobloc compressible (brevet en instance de l’Andra & CMC). Il s’agit d’un nouveau type de revêtement de tunnel particulièrement innovant.Cette thèse est consacrée à la création d’un modèle numérique capable de reproduire le comportement mécanique d’un couche granulaire très compressible à l’aide de la méthode aux éléments discrets (DEM) en 3D. Le milieu granulaire est constitué de particules d’argile cylindriques creuses appelées textitcoques. Chaque coque est un tube de 2 cm de long avec un diamètre de 2 cm. La faible épaisseur de la coque cylindrique la rend essentiellement constituée de vide entourée d’une fine couche d’argile. Dans le modèle, un cluster sécable (la coque) est généré à l’aide de clumps sphéro-polyédriques allon- gées . Ces clumps, appelés secteurs, sont associés entre eux en utilisant deux lois de contact adhésives. Si la combinaison des forces de contact normales et tangentielles satisfait un critère de charge spécifique, la coque se casse au niveau de l’interface entre les deux secteurs. L’outil DEM Rockable mis au point pour cette recherche peut fonctionner sur ces particules fragiles. Les propriétés mécaniques des coques, composé de 12 à 24 secteurs, sont ajustées à l’aide d’essais de compression radiale uniaxiale (verticale). Les expériences à l’échelle du grain sur les coques en argile cuite ont servi de référence. Nous avons déterminé la plage réelle de rupture et sa distribution statistique (Weibull). Les paramètres numériques et mécanique ainsi obtenus ont été validés avec succès dans le cas de la compression radiale d’une coque contrainte latéralement.Dans un premier temps, l’étude des assemblages de coques porte sur la caractérisation expérimen- tale des échantillons avec un controle sur les variables d’état initiales telles que la densité et l’orienta- tions des coques. La reconstruction 3D à partir de tomographies à rayons X d’échantillons de coques carottés dans l’extrados d’un voussoir nous a permis de caractériser l’anisotropie de l’orientation des particules. Il s’agit là d’une information précieuse pour la génération d’échantillons numériques ayant les caractéristiques initiales pertinentes. Deuxièmement, des simulations DEM de compressions oedo- métriques sur des échantillons de ⟨2 000⟩ coques sont réalisées. Une étude paramétrique permet de mettre en évidence le rôle des variables d’état initiales. Un ensemble bien choisi de variables initiales et des paramètres DEM correctement adaptés permettent d’obtenir des simulations prédictives pertinentes pour une comparaison avec les expériences de laboratoire. Une analyse micro-mécanique de l’effet de la proportion des grains cassés sur les contraintes locales exercées sur les coques (et les fragments) est effectuée. Il est observé que la rupture des coques entraîné une compressibilité élevée du matériau. Par conséquent, la réponse mécanique en déformation est considérée comme une conséquence directe de l’évolution de la rupture des particules. Pour finir, un modèle analytique de prédiction de la re- lation Contrainte↔Déformation est proposé dans le cas de la compression oedométrique. Ce modèle prédictif tient compte des variables internes du milieu granulaire comme la résistance mécanique en compression des coques. / The National Agency for Radioactive Waste Management (FR Andra) in France suggested a new way to design a tunnel lining, especially, beneficial in the case of very deep tunnels. To avoid very thick tunnel segments, they propose to integrate a layer of granular material on the extrados of the thinner lining. This approach takes the advantages of the compressible capacity of the crushable particles and the load transfer in the granular material. A tunnel segment with such design is called a Mono-block Compressible Arch-segment VMC (Andra’s & CMC’s pending patent) and is an innovative new type of tunnel linings.This PhD dissertation is dedicated to the creation of a numerical model capable of reproducing the mechanical behaviour of this compressible granular layer using 3D Discrete Element Method (DEM). The granular packing is made of the brittle hollow coarse-size cylindrical particles, called shells. Each shell is a 2 cm long tube with a diameter of 2 cm. Its small thickness makes the cylindrical shell mainly made of void surrounded by a thin layer of clay. In the model, a breakable cluster (shell) is generated using sphero-polyhedral elongated clumps. These clumps, called sectors, are glued together using two adhesive contact force laws. If the combination of the normal and tangential contact forces exceeds a suitable failure criterion, a de-clustering of the shell (breakage) occurs. The DEM tool Rockable devel- oped for this research can operate on such crushable particles. The mechanical properties of the shell model, composed of 12 to 24 sectors, are adjusted in the case of a uniaxial (vertical) radial compres- sion of shells. The preceding grain-scale experiments on the true shells made of baked clay serve as a reference. We determine the true range of the failure tensile load and its statistical Weibull distribu- tion. The user-specified parameters is then successfully validated in the case of radial compression of a horizontally constrained shell.Firstly, the macroscopic study of shell assemblies focuses on the experimental characterisation of the samples with a control of the initial state variables like a number density and a spatial arrangement of shells (shells orientations). 3D reconstruction from X-ray tomographies of the original coated shells samples extracted from the extrados of a tunnel segment help us to characterise the anisotropy of the shells orientation. This is a piece of valuable information to the generation the numerical samples of shells with relevant initial features. Secondly, a series of DEM oedometric tests on ⟨1 000 : 2 000⟩ shells is simulated. A parametric study successfully leads to the understanding of each internal state variable role. A well-chosen set of initial variables with properly adapted DEM parameters give the relevant predictive simulations for a final comparison with the experimental oedometer tests. Thanks to a discrete insight into the micromechanics, the evolutions of the breakage level, the orientation anisotropy and the local stresses exerted on the shells (and/or the fragments) are quantified during the compression. The breakage of the shells result in high compressibility of the material. Therefore, the mechanical response is seen as a consequence of the breakage evolution. Finally, an analytical model is suggested in order to predict the Stress↔Void ratio relationship knowing the initial state of the sample and the tensile strength of the constituents: the shells.

The thesis focuses on the design of the underground garage in the centre of Brno under the Petrov hill. The main target of the thesis is to design spatial arrangement of the underground space and its feasibility study. In the following parts the design of the structural solution and its check calculation is carried out.

Shotcrete (sprayed concrete) was used for the first time in 1914 and has become of  growing importance in stabilizing the excavated tunnel sections over the past century.  Even though the technology develops, there are some difficult tasks such as the design of a bolt anchored tunnel lining made of shotcrete. A proven and established design method does not exist today; instead the design of tunnel linings are based on trial and error or experience from similar projects. One method used today, to determine the actual structural behavior of fiber reinforced shotcrete, is the standard beam test method. Previous studies have shown that the beam method gives scattered results since the testing volume are relatively small and the fibers might be unevenly distributed.  In 1998, an alternative to determine the actual structural behavior of reinforced shotcrete was proposed, based on using round determinate panels. In 2004 this method became a part of the American Society for Testing and Materials, ASTM, standards. The method has the potential of becoming a major, reliable test procedure that better reproduce the behavior of reinforced shotcrete in situ, compared to test beams. An experimental test series was performed to compare the different testing methods in terms of data variability and validity, in the laboratory of Vattenfall in Älvkarleby. The experiment was performed on 30 specimens in total, with five different concrete recipes. The difference in the recipe was the fiber and cement content. The round panels are designed according to ASTM C-1550 and the beams according to SS-EN14488-3. The results from the experiment is here presented and evaluated, and also including the data variability and validity for the proposed method. The two basic testing methods of using beams and round panels are investigated, compared and evaluated, and their advantages and disadvantages discussed. / Sprutbetong användes första gången år 1914 och har under det gångna århundradet blivit allt viktigare för att stabilisera utsprängda tunnelsektioner. Trots att tekniken utvecklas finns det svårigheter med att exempelvis utforma bultförankrade tunnelbeklädnader av sprutbetong. En beprövad och etablerad metod att konstruera sprutbetongbeklädnad existerar inte idag. Istället används erfarenhetsåterföring från tidigare projekt och/eller experimentella försök. En testmetod som används idag för att återskapa beteendet hos sprutbetong är balkförsök. Tidigare studier har däremot visat att resultaten från försöken oftast har stor spridning vilket kan bero på att brottytorna är små areor där fibrerna kan vara ojämnt fördelade vilket påverkar resultaten. År 1998 föreslogs en alternativ metod för att fastställa de mekaniska egenskaperna hos sprutbetong, baserat på användning av runda plattor. År 2004 blev denna metod en del av the American Society for Testing and Materials, ASTM, standarder. Metoden har potential att bli en viktigt och tillförlitligt testmetod som mer realistiskt efterliknar beteendet hos fiberarmerad sprutbetong jämfört med balkprovning. En experimentell försöksserie har genomförts hos Vattenfall i Älvkarleby, för att jämföra de två metoderna med avseende på mätosäkerhet. Försöksserien är på totalt 30 prover, där fem olika betongrecept använts. Cementmängden och fiberhalten varierade mellan de olika recepten. De runda plattorna är utförda enligt ASTM C-1550 och balkarna enligt SS-EN14488-3. Resultaten från försöken har redovisats och utvärderats, och en mätosäkerhersanalys presenteras för metoden ASTM C-1550. Korrelationen mellan resultaten från de två metoderna är beräknad och varianskoefficienten presenteras. För- och nackdelar mellan båda testmetoderna diskuteras.