Thesis (M.Hous.M.)--University of Hong Kong, 2003. / Also available in print.

Thesis (M.Sc.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 125-131) Also available in print.

Thesis (M. Sc.)--University of Hong Kong, 2005.

Thesis (M. Hous. M.)--University of Hong Kong, 2007.

No description available.

La traction ferroviaire est apparue au XIXème siècle. Son développement est dû au fait qu’elle permet le déploiement de modes de transports de masses, économiques, fiables et sécurisés. Il a été rendu possible par la mise en œuvre de moyens techniques et humains considérables qui doivent perdurer pour assurer son bon fonctionnement. Nous aurions tort de penser qu’il est aisé de faire circuler des trains à grandes vitesses à 3 minutes d’intervalle pour assurer le meilleur service possible tout en garantissant la sureté des voyageurs par exemple. Ceci rend la problématique ferroviaire particulière, et intéressante, car elle se situe à l’interface de différents métiers qui doivent tous être coordonnés.La difficulté d’évaluation des situations ferroviaires a mené au développement d’outils de simulation spécifiques dont il est aujourd’hui impossible de se priver pour entretenir, modifier ou étendre le réseau. Ces travaux se focalisent ainsi sur les outils d’aide au dimensionnement des installations de tractions électrique. Ces dernières constituent le cœur même du système puisque c’est à travers elles que le réseau s’alimente en énergie. Le coût énergétique a toujours été au centre des préoccupations et est à nouveau la raison profonde qui motive ces travaux. En effet, si le réseau n’a jamais cessé d’évoluer avec l’émergence de nouvelles technologies visant à diminuer le coût énergétique, la tendance va aujourd’hui en s’accélérant pour chercher et développer de nouveaux de dispositifs ou mode d’exploitation autorisant des économies substantielles. Se posent alors les problématiques liées à la recherche de telles solutions et à leur déploiement. Les considérations techniques liées à leur intégration au sein du réseau, leur intérêt économique, … doivent être étudié selon des modèles assurant un bon degré de précision. Les outils de simulation doivent donc être en mesure de lier au sein d’une même modélisation, d’un même environnement informatique, des problématiques connexes comme le déplacement des trains sur le réseau et le fonctionnement du réseau d’installations électriques (tels les simulateurs existants) et également considérer des modèles spécifiques permettant l’étude de nouvelles solutions (tel les smart grid, l’élaboration d’un trafic coordonnée optimal du point de vue énergétique …). Nous présentons alors le sujet de cette thèse qui traite de la conception d’un simulateur évolutif dont le modèle est élaboré pour prendre en compte les technologies futures et donc être un système ouvert.Nous avons deux objectifs majeurs. D’une part nous devons être en mesure de réaliser un modèle de réseau électrique ferroviaire qui assure le même degré de finesse du réseau que les modèles déjà en place. Vu les enjeux liés à la qualification des résultats nous nous imposons de réutiliser les modèles existant au maximum. Ceci met bien sur des contraintes supplémentaires de réalisation. D’autre part l’architecture que nous proposons (et le modèle informatique de cette architecture) doit pouvoir évoluer facilement. Afin de pouvoir garantir ces objectifs nous devons dissocier clairement les modèles physiques des problèmes liés à l’architecture logicielle elle-même Nous cherchons donc à proposer un environnement selon une approche originale qui s’inscrit dans une démarche d’ingénierie dirigée par les modèles. / The rail traction appeared in the nineteenth century. Its development is due to the fact that it allows the deployment of mass transport modes, economic, reliable and secure. It was made possible by the implementation of considerable resources - technical and human - that have to perdure in order to ensure proper railway network operation. It would be wrong to think that it is easy to circulate to high speed trains to 3 minutes apart to ensure the best possible service while ensuring the safety of passengers. This makes the railway problematic special and interesting because it lies at the interface of different trades which must be coordinated.The difficulty of assessing situations rail led to the development of specific simulation tools. Now they can't be ignore to maintain, modify or expand the network. Therefore this work will focus on simulation tools that aid to the design of railway power supply installations. These are the very heart of the system since they provides the power through the system. The energy cost has always been a central concern and it is again the underlying reason that motivates this work. Indeed, if the network has continued to evolve with the emergence of new technologies to reduce the energy cost, the trend is accelerating today to seek and develop new devices or operating mode that allow substantial savings. This raises issues related to the search for such solutions and their deployment. The technical considerations related to their integration within the network, their economic interest ... shall be considered as models ensuring a good degree of accuracy. Simulation tools must be able to link in a same model - the same computing environment - related problems such as movement of trains on the network and the operation of the network power supply installations (such existing simulators) and also consider specific models for the study of new solutions (such as the smart grid, the development of an optimal coordinated traffic ...). Then we present this thesis which deals with the design of an evolutionary simulator whose the model is developed to accommodate future technologies and thus must be an open system.We have two major objectives. On the one hand we have to be able to realize a railway simulator that provides the same degree of finesse that models already in place. Given the issues qualifying results we impose reuse existing models to the maximum. This puts additional stress on designing the simulator. On the other hand the architecture we propose (and the computer model of this architecture) must evolve easily. In order to ensure these objectives we must clearly separate the physical models of problems related to software architecture itself. Therefore we offer an environment using an original approach that fits the approach of model driven architecture.

LKAB and Trafikverket want to increase the maximum allowed axial load from 30 tons to 32,5 tons for the northern part of Malmbanan. There are ongoing investigations of the condition of the railway with the current axial load of 30 tons. The investigations do not include one of Trafikverket's concerns about the condition of the railway. That question is how the periodical load from trains affect the stability and maintenance cost of the railway embankment. The aim of this thesis is therefore to do a preliminary investigation of how the excess pore pressure is developed in the railway embankment during periodical loading and an attempt to model it the help of PLAXIS2D, a finite element software. PLAXIS2D has been used to model a simplified section of section km 1449+820 that is subjected by periodical loading with an axial load of 30 tons. There are 6 created models in the thesis where model 2-6 origin from model 1 but with some minor changes. The changes between the models are the train speed, groundwater level, width of the embankment and load. The periodical load applied in all models has been assumed to load the embankment with a periodical shape of a sinus curve. From the models, the distribution of the effective stress and excess pore pressure have been measured. The total displacement and the magnitude of excess pore pressure in different measuring points in the embankment have also been measured. These results have been used to analyze why there are certain points in the embankment which accumulate excess pore pressure. In the models, measuring points have also been created beneath the sleeper and in the embankment toe where total displacement and effective stress have been measured to relate and see if the response in stress and displacements are trustworthy. It was concluded that accumulation of excess pore pressure is relative high in the embankment toe due to the stress distribution and slope stability. The embankment is developing large shear stresses in the embankment toe to resist against slope failure. The excess pore pressure is recommended to be measured in the embankment toe, but it is also recommended to develop the model further since it does not consider any dynamics and neither soil stiffening or soil softening which limit the possibility to analyze liquefaction in detail.

Accurate predictions of ground-borne vibration levels in the vicinity of an underground railway are greatly sought after in modern urban centers. Yet the complexity involved in simulating the underground environment means that it is necessary to make simplifying assumptions about this system. One such commonly made assumption is to ignore the effects of nearby embedded structures such as piled foundations and neighbouring tunnels. Through the formulation of computationally efficient mathematical models, this dissertation examines the dynamic behaviour of these two particular types of structures. The effect of the dynamic behaviour of these structures on the ground-borne vibration generated by an underground railway is considered. The modelling of piled foundations begins with consideration of a single pile embedded in a linear, viscoelastic halfspace. Two approaches are pursued: the modification of an existing plane-strain pile model; and the development of a fully three-dimensional model formulated in the wavenumber domain. Methods for adapting models of infinite structures to simulate finite systems using mirror-imaging techniques are described. The interaction between two neighbouring piles is considered using the method of joining subsystems, and these results are extended to formulate models for pile groups. The mathematical model is validated against existing numerical solutions and is found to be both accurate and efficient. A building model and a model for the pile cap are developed, and are attached to the piled foundation. A case study is used to illustrate a procedure for assessing the vibration performance of pile groups subject to vibration generated by an underground railway. The two-tunnel model uses the superposition of displacement fields to produce a fully coupled model of two infinitely long tunnels embedded in a homogeneous, viscoelastic fullspace. The significance of the interactions occurring between the two tunnels is quantified by calculating the insertion gains that result from the existence of a second tunnel. The results show that a high degree of inaccuracy exists in any underground-railway vibration prediction model that includes only one of the two tunnels present.

No abstract included. / Arts, Faculty of / History, Department of / Graduate

This thesis considers the Pacific Great Eastern Railway, the British Columbia Railway as of April 1, 1972, a Provincial Crown corporation, and the implications of its extensions upon regional development. The indicators of regional development studied are population and industrial profiles. The time framework of the thesis is from 1952 to 1972, the period of the P.G.E. extensions. Two perspectives of the implications for regional development are examined. Chapter Two treats with the Provincial Government agencies whose policies have had the most effect in the study area. The financing, safety, and freight rate implications of the P.G.E. are discussed. In addition, general policies and inter-relationships with the P.G.E. of the following Provincial agencies are considered: B.C. Hydro, the Department of Highways, and the Forest Service. The third through sixth chapters consider the regional development of four regions: Squamish-Cariboo, Prince George, Peace River-Liard, and Omineca-Stikine. These regions, in turn, are broken into areas—usually to correspond with a central P.G.E. railway station and its commodity carloadings. The development within each area is studied in respect to population changes and industrial expansion since 1951. The P.G.E. commodity carloadings from 1966 through 1970 are used as indicators of regional development. The fluctuations of the carloadings of certain commodities, such as woodchips, lumber and veneer, merchandise, and machinery and parts, have been used to show the level of regional industrial development. Alone, the P.G.E. commodity carloadings are of little use. However, they take on more meaning in light of the policies of the Provincial Government agencies. The usefulness of the data takes a quantum leap when individual shippers indicate how much they ship, its routing, and its final destination. A limited attempt at this later refinement is provided by the responses of about fifty company and government officials to a single page, open-ended question letter. Most of these responses are in letter form although those companies with offices in Vancouver are interviews. A limitation of the technique used in this thesis to determine regional development is the inability to estimate the importance of the service sector. The obvious weight is given to the resource extraction and manufacturing sectors since these are the sectors which generate railway carloadings. Only when there is a significant population and the total carloadings are relatively low, are there suspicions of a large service sector or the possibility of significant truck shipments. The general conclusion to this thesis is that the Pacific Great Eastern Railway has stimulated regional development in the areas it serves directly. However, this development has been primarily in the forest products industry, in conjunction with Forest Service policies and technological improvements. The development of this industry has then provided a stimulus for maintenance and repair services and a more stable population base, which has helped to establish a need for improved highways. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate