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Thesis (M.S. in Mechanical Engineering)--Tufts University, 2000. / Title from PDF title screen. "PB2008-110256." Includes bibliographical references (p. 80-82). Also available online.

Thesis (M.Arch.)--University of Hong Kong, 1994. / Includes special report study entitled : Urban space study. Includes bibliographical references. Also available in print.

Thesis (M.Arch.)--University of Hong Kong, 1997. / Includes special report study entitled : Notion of place. Includes bibliographical references. Also available in print.

Orientador: Cassio Eduardo Lima de Paiva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-25T18:39:41Z (GMT). No. of bitstreams: 1 Benzi_JoyceFelisbinaCarpanez_M.pdf: 4589963 bytes, checksum: d5c188f05dc140935277219394181843 (MD5) Previous issue date: 2014 / Resumo: As passagens em nível são formadas pela interseção de vias de dois modais de transporte terrestres com características físicas e operacionais distintas. Estas travessias são gargalos no sistema de transportes rodoviário. Os motoristas são obrigados a parar seus veículos antes de atravessar um cruzamento rodoferroviário, devido ao direito de passagem adquirido pela ferrovia, que por sua vez, também reduz a sua velocidade para evitar colisões, principalmente no perímetro urbano. Estas interseções são trechos de descontinuidade para a via, onde o fluxo rodoviário e o Nível de Serviço ficam reduzidos consideravelmente. Com base nessa situação foi realizado um levantamento de campo, em seis passagens em nível, na região Sudeste do país para a avaliação dos fluxos operacionais dos veículos rodoviários existentes. Através destes dados pretende-se desenvolver uma análise crítica dos volumes escoados através de métodos que estimam o fluxo de saturação e o atraso veicular. Para valores referentes ao tempo de espera dos usuários são encontrados Níveis de Serviço correspondentes, onde é possível classificar a viabilidade das vias existentes. Enquanto para novas vias foi desenvolvido um gráfico dinâmico exibindo os números máximos de veículos e trens que podem utilizar o sistema de acordo com o nível de serviço exigido, consequentemente a viabilidade da via / Abstract: The highway-rail grade crossings are constituted by the intersection of two modals of transportation with distinct physical and operational characteristics. These crossings are the bottlenecks in the highway transportation system. The drivers are required to stop their vehicles before cross a grade crossing, due the right-of-way acquired by the railroad, which in turn also reduce your speed to avoid collisions, principally in the urban perimeter. Theses intersections are points of discontinuity for the way, where the flow is reduced and the road service level is reduced considerably. Based on this situation was conducted a field survey in six level crossings in the Southern Brazil for the evaluation of operational flows of existing road vehicles. Through these information, will be develop a critical analysis of the volumes disposed of by methods that estimate the saturation flow and vehicular delay. Amounts related to the waiting time for users are found corresponding Level of Service where you can sort the viability of existing roads. While for new roads was develop a dynamic graphic showing the maximum numbers of vehicles and trains that can use the system according to the level of service required, hence the viability of the road / Mestrado / Transportes / Mestra em Engenharia Civil

M.Ing. / Sound pressure levels exceeding acceptable limits are being generated by trains travelling on the 1000 m radius curved railway line past the town of Elands Bay. Unacceptable sound levels are attributed mainly to top of rail wheel squeal. Top of rail wheel squeal belongs to the family of selfinduced vibrations and originates from frictional instability in curves between the wheel and the rail under predominantly saturated lateral creep conditions. In small radius curves, saturated lateral creep conditions occur due to the steering of railway wheelsets with large angles of attack. Given the large curve radius and the utilisation of self-steering bogies on the Sishen-Saldanha Iron Ore railway line, curve squeal is a highly unexpected result for the 1000 m radius curved railway line. This is because curving of bogies in large radius curves are achieved without high wheelset angles of attack leading to saturated creep conditions. An experimental and analytical investigation was carried out to identify the mechanisms influencing the generation of wheel squeal in large radius curves. Simultaneous measurement of sound pressure and lateral wheel-rail forces were made during regular train service in one of the two 1000 m radius curves at Elands Bay to characterise the bogie curving behaviour for tonal noise due to wheel squeal occurring in the large radius curve. The lateral force curving signature not only reveals the levels of lateral wheel-rail forces required for bogie curving, but also whether the bogie is curving by means of the creep forces generated at the wheel-rail interface only or if contact is necessitated between the wheel flange and rail gauge corner to help steer the bogie around the curve. The test set-up consisted of two free field microphones radially aligned at equivalent distances towards the in – and outside of the curve in line with a set a strain gauge bridges configured and calibrated to measure the lateral and vertical forces on the inner and outer rail of the curve. This test set-up allowed the squealing wheel to be identified from the magnitude difference of the sound pressures recorded by the inner and outer microphones in combination with comparing the point of frequency shift of the squeal event due to the Doppler Effect with the force signals of the radially aligned strain gauge bridges. From the experimental phase of the investigation, it was found that wheel squeal occurring in the 1000 m radius curve at Elands Bay is characteristic of empty wagons and is strongly related to the squealing wheel’s flange/flange throat being in contact with the gauge corner of the rail. Here high levels of spin creepage associated with high contact angles in the gauge corner lead to high levels of associated lateral creepage necessary for squeal generation. This is in contrast to lateral creepage due to high wheelset angles of attack being the key kinematic parameter influencing squeal generation in small radius curves. Furthermore, the amplitude of wheel squeal originating from the passing of empty wagons was found to be inversely proportional to the level of flange rubbing on the squealing wheel i.e. increased flange contact on the squealing wheel brings about a positive effect on squeal control. Contrary to the empty wagons which are characterised by tonal curve squeal, loaded 4 wagons requiring contact between the wheel flange and rail gauge corner in the 1000 m curve was characterised by broadband flanging noise. It was concluded from measurements that flange contact occurring under high lateral forces for steady state curving of loaded wagons provides the complete damping necessary for squeal control. The curve squeal noise that originated from the passing of empty wagons in the Elands Bay curve could further be classified according to the frequency at which the squeal event manifested itself in the curve, i.e. low frequency audible (0 – 10 kHz), high frequency audible (10 – 20 kHz) and ultrasonic squeal (> 20 kHz). The vast majority of low frequency audible squeal events recorded in the 1000 m Elands Bay curve occurred at approximately 4 kHz and originated from the low rail/trailing inner wheel interface, whilst the vast majority of high frequency audible squeal events occurred in the frequency range between 15 and 20 kHz and originated from both the high rail/leading outer wheel and low rail/trailing inner wheel interfaces.

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