Freeways have had a strong influence not only on the urban transportation but also on downtown areas both physically and socially. Certainly, they have extended the commuting limits of the city and made lower land costs more accessible. However, many of the mid-century freeways, once championed by planners as tools for urban renewal, have created swaths of blight through city neighborhoods. Their negative impacts on the larger urban framework requires new ideas for healthier alternatives to aid in preserving and building sustainable cities. Removal of any downtown highway requires careful thought— even more consideration than when it was built. Quick solutions are what resulted in the problems that downtown highways of the Interstate-Era have today. If it is the simple interactions between people and place are that make up the positive aspects an urban environment, then what are the possibilities and strategies for removing urban highway, which are one of the primary impediments separating people in place in contemporary cities? This question is the focus of this thesis. At its core, the removal of freeways represents a trade-off between mobility objectives and economic development objectives. Evidence from other cities’ decisions to redesign or remove their downtown highways suggests multiple benefits. Making design changes, such as to replace a downtown highway with a well-designed surface boulevard, can stimulate economic activities without necessarily causing traffic chaos. Solutions come in different shapes and sizes. The selected case studies in this thesis reflect a diversity of approaches – suggesting no single strategy exists for addressing downtown highway issues. This reflects the fact that multiple alternatives must be considered in every situation because each approach varies in costs and opportunities. A typology of highway alternations derived from the case studies includes seven different techniques: burying, demolishing, taming, capping or bridging, elevating, retaining, and relocating. The final chapter applies the conclusions from the case studies to the Downtown Connector– Interstate 75/85– in Downtown Atlanta, Georgia. Urban design and transportation planning has an emerging new set of values. Transportation planning is seeking to promote alternate modes of transportation to the private vehicle, like transit, by foot, or by bicycle. We now understand that connectivity is not served only by highways but also by urban street networks that invite modes other than just automobiles. An important role for urban design will be to shape the way these interactions are made to benefit the citizens, its urban spaces, and the economy.

Made available in DSpace on 2015-03-26T13:28:35Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3487297 bytes, checksum: 440345c34c1ab5834f45b26ae9b87375 (MD5) Previous issue date: 2014-09-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work presents the development of a parametric study on Crestbond shear connector through numerical modeling, evaluating its behavior with respect to strength and to the relative displacement between the concrete slab and the shear connector. The study covers the conception and improvement of numerical models for the parametric study, the development of an extensive research on the connector s parameters affecting its behavior, and an equation to predict the connector s ultimate strength, proposed at the end. The numerical models were created within the Finite Element software Abaqus, using nonlinear analysis and the concrete damaged plasticity model. The parametric study consisted on the analysis of 88 numerical simulations of push-out tests, as described on EN 1994-1-1:2004. The connection behavior was studied through these numerical tests. The obtained results allowed to define how each studied parameter influences the connector s behavior. It was also possible to define the desirable characteristics for the connector to be used in practice. In addition to these results, it was proposed a semi-empirical equation to evaluate the connector s ultimate strength which showed excellent correlation with most of the models, both experimental and numerical. / Este trabalho consiste no desenvolvimento de um estudo paramétrico do conector de cisalhamento tipo Crestbond por meio de modelagem numérica, avaliando o comportamento do conector quanto à capacidade resistente e ao deslizamento relativo entre conector e laje. O trabalho envolve o aperfeiçoamento e concepção de modelos numéricos para o estudo do conector, uma ampla investigação dos parâmetros que afetam o comportamento do conector, além da proposição de uma equação para a predição da sua capacidade resistente. Os modelos numéricos utilizados foram elaborados por meio do software de elementos finitos Abaqus, utilizando análise não-linear e o modelo de dano com plasticidade. O estudo paramétrico consistiu na análise de 88 simulações numéricas de ensaios tipo push-out, conforme a EN 1994-1-1:2004. Os resultados obtidos permitiram determinar como cada parâmetro estudado influencia o comportamento do conector e quais as características desejáveis para a aplicação do mesmo. Ao final do trabalho, propôs-se uma expressão semiempírica para a estimativa da carga máxima do conector que apresentou excelente correlação com grande parte dos modelos, tanto experimentais quanto numéricos.

Recentemente a utilização de estruturas mistas, aço concreto, vem ganhando espaço nas construções. Isso deve-se principalmente a economia de tempo em sua execução. Além disto, nesta solução a utilização do aço e do concreto otimiza as características estruturais de seus elementos: a resistência a tração do aço e a compressão do concreto. A transferência dos esforços entre os dois materiais possui grande influência no desempenho de uma estrutura mista, sendo comum a utilização de conectores de cisalhamento na região da interface entre estes dois materiais. O Eurocode 4 define um ensaio experimental denominado push-out de modo a determinar a resistência e ductilidade de conectores de cisalhamento. Seu desempenho é influenciado pelas resistências do concreto a compressão, as dimensões e taxa de armadura da laje de concreto, dimensões do perfil de aço, a disposição e a geometria dos conectores e pelas características dos aços utilizados no conector, no perfil e nas barras de reforço. Nota-se com isso uma grande quantidade de variáveis que influenciam o ensaio. Assim, o presente trabalho apresenta o desenvolvimento de um modelo em elementos finitos com base no programa ANSYS para simulação de ensaios push-out. Os resultados numéricos apresentados neste trabalho foram calibrados com resultados obtidos em ensaios experimentais existentes na literatura de ensaios push-out para conectores do tipo pino com cabeça (stud) e conectores tipo perfobond. Estes últimos apresentam elevada resistência sendo influenciados por inúmeros fatores como: número e diâmetro dos furos no conector e a inclusão ou não de barras de reforço extras nestes furos. / A continuous increase of the use of (steel & concrete) composite structures in constructions can be recently observed. This is mainly due to its faster execution time when compared to other construction alternatives. Additionally, these solutions optimize the structural characteristics of the involved materials: the steel tension capacity and the concrete compressive strength. The transfer of forces between these different materials greatly influences the composite structure performance, where typical solutions uses shear connectors at the concrete to steel interface. The Eurocode 4 defines an experimental test, denominated push-out, to determine the shear connectors strength and associated ductility capacity. Its performance is influenced by the concrete compressive strength, slab dimensions and adopted reinforcing bar area, steel profile dimensions, shear connectors geometry and disposition and by the mechanical characteristics of the connector, profile and reinforcing bars steels. All these aspects indicate that a great number of variables can influence the test. This study presents the development of a finite element model, based on the ANSYS program, to simulate push-out tests. The numerical results presented in this investigation were calibrated against experiments reported in the literature for stud and Perfobond shear connectors. The Perfobond connectors present a substantial shear capacity being influenced by several factors like: connectors hole number and diameter and by the adoption, or not, of extra reinforcing bars passing through the connector holes.

Recentemente a utilização de estruturas mistas, aço concreto, vem ganhando espaço nas construções. Isso deve-se principalmente a economia de tempo em sua execução. Além disto, nesta solução a utilização do aço e do concreto otimiza as características estruturais de seus elementos: a resistência a tração do aço e a compressão do concreto. A transferência dos esforços entre os dois materiais possui grande influência no desempenho de uma estrutura mista, sendo comum a utilização de conectores de cisalhamento na região da interface entre estes dois materiais. O Eurocode 4 define um ensaio experimental denominado push-out de modo a determinar a resistência e ductilidade de conectores de cisalhamento. Seu desempenho é influenciado pelas resistências do concreto a compressão, as dimensões e taxa de armadura da laje de concreto, dimensões do perfil de aço, a disposição e a geometria dos conectores e pelas características dos aços utilizados no conector, no perfil e nas barras de reforço. Nota-se com isso uma grande quantidade de variáveis que influenciam o ensaio. Assim, o presente trabalho apresenta o desenvolvimento de um modelo em elementos finitos com base no programa ANSYS para simulação de ensaios push-out. Os resultados numéricos apresentados neste trabalho foram calibrados com resultados obtidos em ensaios experimentais existentes na literatura de ensaios push-out para conectores do tipo pino com cabeça (stud) e conectores tipo perfobond. Estes últimos apresentam elevada resistência sendo influenciados por inúmeros fatores como: número e diâmetro dos furos no conector e a inclusão ou não de barras de reforço extras nestes furos. / A continuous increase of the use of (steel & concrete) composite structures in constructions can be recently observed. This is mainly due to its faster execution time when compared to other construction alternatives. Additionally, these solutions optimize the structural characteristics of the involved materials: the steel tension capacity and the concrete compressive strength. The transfer of forces between these different materials greatly influences the composite structure performance, where typical solutions uses shear connectors at the concrete to steel interface. The Eurocode 4 defines an experimental test, denominated push-out, to determine the shear connectors strength and associated ductility capacity. Its performance is influenced by the concrete compressive strength, slab dimensions and adopted reinforcing bar area, steel profile dimensions, shear connectors geometry and disposition and by the mechanical characteristics of the connector, profile and reinforcing bars steels. All these aspects indicate that a great number of variables can influence the test. This study presents the development of a finite element model, based on the ANSYS program, to simulate push-out tests. The numerical results presented in this investigation were calibrated against experiments reported in the literature for stud and Perfobond shear connectors. The Perfobond connectors present a substantial shear capacity being influenced by several factors like: connectors hole number and diameter and by the adoption, or not, of extra reinforcing bars passing through the connector holes.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Precast concrete panels reveal an important architectural and structural function for constructions, and their use has grown in Brazil. Previous studies indicate the panels contribution in reducing efforts and displacements in the main structure, resulting in more economical structures. This work analyzes the panels interaction with the main structure via numerical analysis by using the ANSYS Software, under the effect of lateral actions. Two analyses of one-floor structures are developed: one is constituted of vertical panels connected to the beam and the other one is constituted of horizontal panels connected to the columns, using SOLID65, SOLID45, SHELL63, BEAM4, BEAM44, TARGE170, and CONTA173 finite elements. Results show the importance of the contribution of panels towards the stiffness of the main structure, promoting a reduction in the structure s displacements. Such stiffness causes stresses in the panels and in the connectors, being the latter the most critical. Quite often these stresses are not considered in the structural project. In the second analysis, with the horizontal panels connected to the columns via plate connection, results show that the precast panels contribution to the stiffness of the main structure is highly significant and it is affected by the eccentricity of the connection with occurrence critical stress in the connections and increases as the plate s thickness decreases. The use of plates with greater thickness results in less stress, but they transfer lateral bending to the precast panels. The thermal effect s consideration implies in such a greater tensions in the panels how much in the connections and greater efforts of lateral bending in the panels. The panels contribution may be considered a design strategy, due to the fact that they produce an effective material economy by means of the possibility of reduction of column dimensions. / Os painéis pré-moldados de concreto apresentam função arquitetônica e estrutural importante para as edificações, tendo o seu uso intensificado no Brasil. Estudos anteriores mostram a contribuição dos painéis em reduzir os esforços e deslocamentos da estrutura principal, resultando em estruturas mais econômicas. Este trabalho avalia a interação dos painéis com a estrutura principal por meio de análise numérica utilizando o software ANSYS (versão 9.0), sob o efeito das ações laterais. São desenvolvidas duas análises de estruturas de pavimento único (galpão), uma constituída por painéis verticais fixados na viga e outra por painéis horizontais fixados nos pilares, utilizando-se os elementos finitos SOLID65, SOLID45, SHELL63, BEAM4, BEAM44, TARGE170 E CONTA173. Os resultados obtidos mostram que os painéis contribuem no enrijecimento da estrutura principal, promovendo uma diminuição dos deslocamentos da estrutura. Verifica-se, também, que este enrijecimento ocasiona solicitações nos painéis e nas ligações, sendo estas as mais críticas e, muitas vezes, não são consideradas no projeto estrutural. Na segunda análise, com os painéis horizontais fixados nos pilares por meio de chapas metálicas de ligação, os resultados mostram que a contribuição dos painéis na rigidez da estrutura principal é afetada pelo valor da excentricidade da ligação, com a ocorrência de tensão crítica nas ligações, a qual aumenta com o decréscimo da espessura da chapa. O uso de chapas com espessura maior resulta em menores tensões, mas transferem flexão lateral aos painéis. A consideração do efeito térmico implica em maiores tensões tanto nos painéis quanto nas ligações e em maiores esforços de flexão lateral nos painéis. A contribuição dos painéis pode ser considerada numa estratégia de projeto, uma vez que resulta em economias de materiais por meio da possibilidade de redução da dimensão dos pilares. / Mestre em Engenharia Civil

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-27T17:05:59Z No. of bitstreams: 2 Dissertação - Marcel Willian Reis Sales - 2014.pdf: 4208639 bytes, checksum: b181bf240488740db8489468fb605743 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-27T18:54:00Z (GMT) No. of bitstreams: 2 Dissertação - Marcel Willian Reis Sales - 2014.pdf: 4208639 bytes, checksum: b181bf240488740db8489468fb605743 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-27T18:54:00Z (GMT). No. of bitstreams: 2 Dissertação - Marcel Willian Reis Sales - 2014.pdf: 4208639 bytes, checksum: b181bf240488740db8489468fb605743 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-08-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Composite beams of steel and concrete are studied for some time. The mechanism of transfer of longitudinal shear stresses on the interface between the beam and the slab usually occurs by means of shear connectors. In this case, the set of two materials behavior depends on the strength and rigidity of the connector on the interface, being well known for connectors with pin-type head associated with massive concrete slab. However, there is little information on shear connectors with pin-type head associated with hollowcore slab concrete. This study aims to determine, by means of direct shear tests, the resistance of connectors with pin-type head when associated with cellular slab and precast concrete presence of cover concrete. Hollow core slabs are analyzed with two different heights and concrete cover of 40 mm in thickness. Is also varied the strength of concrete fill and rate of shear reinforcement at the link. The results are compared with normative prescriptions and suggestions for other jobs. At the end, we propose the modification of an expression commonly used to evaluate the resistance of stud bolt and alveolar slab so as to adapt it to the situation of cellular concrete slab with hood. / As vigas mistas de aço e concreto são estudadas há bastante tempo. O mecanismo de transferência de tensões de cisalhamento longitudinais pela interface entre a viga e a laje normalmente se dá por meio de conectores de cisalhamento. Nesse caso, o comportamento conjunto dos dois materiais depende da resistência e da rigidez do conector na interface, sendo bem conhecido para os conectores do tipo pino com cabeça associados com laje maciça de concreto. Entretanto, há pouca informação sobre conectores de cisalhamento do tipo pino com cabeça associados com laje alveolar de concreto pré-moldado. Este trabalho tem por objetivo determinar, por meio de ensaios de cisalhamento direto, a resistência de conectores do tipo pino com cabeça quando associados com laje alveolar de concreto pré-moldado e presença de capa de concreto. São analisadas lajes alveolares com duas alturas diferentes e capa de concreto de 40 mm de espessura. Também é variada a resistência do concreto de preenchimento e a taxa de armadura transversal à ligação. Os resultados são comparados com prescrições normativas e sugestões de outros trabalhos. Ao final, é proposta a modificação de uma expressão normalmente utilizada para avaliar a resistência do conector tipo pino com cabeça e laje alveolar de modo a adequá-la à situação de laje alveolar com capa de concreto.

La realidad peruana refleja una falta de integración de los sistemas de transporte. Asimismo, se evidencia bajos estándares de calidad con relación a las infraestructuras urbanas y una inseguridad hacia el peatón en la ciudad de Lima, un ejemplo de lo mencionado ocurre en la intersección de la Avenida Javier Prado con Aviación. Mediante el software Vissim-Visswalk 9 se realiza una microsimulación que refleja las trayectorias, frecuencias y composiciones vehiculares y peatonales, la cual se calibra y valida respectivamente. La metodología propuesta describe una delimitación de la intersección mencionada, luego se realiza la clasificación de usuarios de transportes públicos y tipos de vehículos para proceder al levantamiento de información dinámica en cuanto al aforo de vehículos y peatones y posteriormente registrarlas en el Vissim-Viswalk 9. De manera cualitativa, la seguridad vial se evalúa mediante la utilización de listas de chequeo las cuales reflejan claramente una inseguridad y alta vulnerabilidad hacia la integridad del peatón evidenciado en los 13 ítems analizados. La propuesta de solución consiste en el diseño de un conector peatonal de 320 metros, el cual cumple con los reglamentos requeridos ya que tiene un ancho efectivo constante de 1.6 metros y una pendiente máxima de 5% y 10% en el conector y en la rampa, respectivamente. Los resultados demuestran que la propuesta permite una reducción del tiempo de transbordo en un 17.1% y un aumento en la velocidad promedio de 26.1%, asimismo se evidencia un aumento significativo de la seguridad vial hacia los peatones. / Peruvian reality reflects a lack of integration of transport systems. In addition, low quality standards are evident in relation to urban infrastructures and a pedestrian insecurity in the city of Lima, an example of what is mentioned at the intersection of Avenida Javier Prado with Aviacion. The Vissim-Visswalk 9 software performs a microsimulation that reflects the trajectories, frequencies and vehicular and pedestrian compositions, which is calibrated and validated respectively. The proposed methodology describes a delimitation of the mentioned intersection, then the classification of public transport users and vehicle types is carried out to carry out dynamic information regarding the capacity of vehicles and pedestrians and subsequently register them in Vissim-Viswalk 9. Qualitatively, road safety is evaluated by using checklists which clearly reflect insecurity and high vulnerability to pedestrian integrity evident in the 13 items analyzed. The solution proposal consists of the design of a pedestrian connector of 320 meters, which complies with the required regulations since it has a constant effective width of 1.6 meters and a maximum slope of 5% and 10% on the connector and on the ramp, respectively. The results show that the proposal allows for a reduction in transfer time by 17.1% and an increase in average speed of 26.1%, and there is also a significant increase in road safety towards pedestrians. / Tesis

Dielectric High-frequency transmission lines are natural alternative to the lines made of metal in term of low loss. These lines are mainly used in microwave techniques of measuring. The main object is to describe basic parameters of metal and dielectric transmission lines and their comparison. Next point is a basic overview of the excitation the lines from metal and it's application on dielectric transmission lines. Then make the simulation of microstrip directional couplers and coupler made by dielectric waveguides. The last point of work is construction these directional couplers and measuring their most important parameters.

This master's thesis deals with the basic principles of slot antennas. Models of antennas were simulated in a selected electromagnetic simulator CST MICROWAVE STUDIO (CST MWS). There are several models of slot antennas which are optimized for communication in the car at a frequency 8 GHz.

The subject of this masters thesis is preliminary design of III. phase connector road of D7 and D8 motorways near Kralupy nad Vltavou. The reason for this highway design is high traffic intensity. The highway is designed as a road type S9,5/90. Highway design includes two junctions. Junctions are designed in two variants, only one variant of each junction was finalized to more in-depth detail.