Concrete bridge rails are rated according to three performance levels. For classification at a given performance level, the rail must meet specific strength and geometric requirements. To meet the strength requirement, the rail must be able to satisfactorily withstand a transverse concentrated load applied at the top of the rail. This load is called F_t (kips) and is listed for each performance level in the Draft NCHRP Project 12-33 document entitled Development of a Comprehensive Bridge Specification and Commentary. Researchers at the Texas Transportation Institute have developed equations to determine R_w (kips), the total transverse resistance of a rail (which must be greater than or equal to F_t), and L_c (ft), the critical length of wall failure (Hirsch 1978). These equations (referred to as Hirsch equations is this study) were developed by yield line analysis for a constant thickness concrete parapet wall. The purpose of this study is to develop similar equations for R_w and L_c based on yield line analysis of a variable thickness New Jersey concrete parapet wall instead of a constant thickness wall. The results from this study indicate that the Hirsch equations significantly over estimate R_w for variable thickness concrete walls where M_c, the flexural resistance of the wall about the horizontal axis, varies substantially over the height of the wall. This study recommends that an average value for M_c, taken over the height of the wall, be used in the Hirsch equations when this situation arises. / Master of Science

As construction of the nation’s interstate highway system nears completion, the emphasis must now be focussed on the rehabilitation of many of the older sections of the system which have undergone damage or deterioration. The efficiency and effectiveness of the concrete removal operation will profoundly affect the outcome of the bridge rehabilitation. Pneumatic breakers, milling machines, and hydro-demolition are three concrete removal technologies utilized to remove concrete that has experienced various levels of damage or deterioration. A general examination of the three technologies is presented in the following five areas: the equipment, the work, production, cost, and quality. The information was primarily obtained through interviews and discussions with persons involved in bridge rehabilitation: contractors, State Highway Agency personnel, and equipment manufacturers and distributors. It is anticipated that the information presented will enable persons involved in the bridge rehabilitation industry to more effectively utilize the technologies discussed. / Master of Science

No description available.

O crescente desenvolvimento na indústria de transporte tornou-se um tema de pesquisa em diversos países, uma vez que as obras de arte especiais até então construídas não foram projetadas para as elevadas cargas atualmente transportadas. Mostra-se necessária uma reavaliação de como a ação do carregamento móvel é levada em consideração. Dessa forma, elaborou-se um estudo de normas e códigos de diversos países sobre o tema. Definem-se algumas combinações de veículos de cargas (CVCs) e analisam-se as conseqüências e a viabilidade do tráfego das mesmas. Essa análise é realizada através da comparação dos esforços solicitantes provocados pelas CVCs e pelos veículos previstos por normas em diversos sistemas estruturais e por meio da verificação da capacidade portante de um projeto típico. Objetivando-se encontrar uma solução que se adequasse à realidade brasileira, é elaborado um estudo sobre como outros países vêm tratando a questão das combinações de veículos de cargas especiais. Ao final do trabalho, constata-se a existência de CVCs que, apesar de atenderem às exigências estabelecidas pelo Conselho Nacional de Trânsito (CONTRAN), são incompatíveis com a as pontes da malha viária nacional. / The increasing development in the transport industry has become a research topic in several countries, once the bridges constructions built to date were not originally designed to support the ever increasing heavy loads nowadays being transported. It is thus necessary a re-evaluation of how the action of live loading is taken in consideration. A study of the codes and specifications of several countries is elaborated. It is defined some cases of combinations of special load vehicles (CVCs) and it is analyzed the consequences and viability of their traffic. This analyses is done by comparing the efforts caused by the CVC\'s to the other normative vehicles in various structural systems and by the verification of the strength capacity of a typical project. In order to find a solution in accordance with the Brazilian reality, a study is elaborated on how other countries manage the combinations of special load vehicles issue. Among other conclusions of this research, it is worth noting that there are CVC\'s that attend the standards established by the National Council of Transportation (CONTRAN) but are not compatible with the bridges of national roads.

O emprego de uma estrutura mista de aço – concreto (laje em concreto e vigas em perfis de aço) representa a priori uma solução mais eficiente para estruturas de pontes do que a consideração de uma estrutura toda em concreto ou toda em aço. No entanto para que isto ocorra na prática é necessário um dimensionamento criterioso desta estrutura, o que deve ser feito tendo como apoio softwares de simulação numérica. No CEMACOM tem sido desenvolvidos vários trabalhos nesse tema, os quais resultaram num código computacional com capacidade para simular vigas mistas submetidas a cargas de curta duração ou cargas de longa duração. Em contraponto, nesse trabalho a proposta é customizar um software comercial de elementos finitos (ANSYS) para realizar as mesmas tarefas. Depois do modelo construído tem se vantagens pois se dispõe da plataforma do ANSYS que permite analisar vários problemas associados ao assunto. Fez-se uma proposta de modelo numérico para se analisar vigas mistas no ANSYS. Tendo como ponto de partida os trabalhos de Lazzari (2015) e Lazzari et al. (2016) para a implementação do comportamento do concreto, fez-se algumas implementações numa rotina tipo usermat para fazer análises de cargas de curta duração. Os efeitos de longa duração, fluência e retração, foram implementados na rotina usermat tendo como base os trabalhos de Dias (2013) e Moreno (2016). O código customizado foi comparado contra resultados experimentais e numéricos que demonstraram o adequado funcionamento do mesmo. Finalmente o ANSYS customizado foi aplicado para modelar uma estrutura de ponte que havia sido previamente calculada por Schmitz (2014) empregando procedimentos de projeto normalizados. Os resultados obtidos são comparados contra o processo normalizado e são apresentadas as vantagens deste processo. / The use of composite steel and concrete structures (concrete deck and steel profile beams) represents a priori a more efficient solution for bridges structure than the consideration of a whole structure with concrete or whole with steel. However for this to occur in practice it is necessary a consistent design of this structure, and this should be done with the support of softwares of numerical simulations. In CEMACOM have been developed many works in this theme, which resulted on a computational code with the capacity for simulate composite beams submitted to loads with short duration or loads with long duration. In counterpoint, in this work the proposal was to customize a commercial software of finite elements (ANSYS) to do the same tasks. After the construction of the model it have advantages because it is able to use the ANSYS platform, which permit to analyze various problems associated with this subject. It was done a numerical model for analysis of composite beams in ANSYS. Considering as the start point the works of Lazzari (2015) and Lazzari et al. (2016) for the implementation of concrete behavior, some implementations were done in a routine of the type usermat to make analysis with loads with short duration. The effects of long duration, creep and shrinkage, were implemented on the usermat routine considering the jobs of Dias (2013) and Moreno (2016). The customized code was compared with experimental and numerical results that demonstrated a proper functioning. Finally, the customized ANSYS was applied to modeling a bridge structure, which was previously designed in Schmitz (2014) using standard proceedings. The obtained results are compared with the standard procedure and it is presented the advantages of this more complex proceeding.

Lau Tin Hang, Peter. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2002-2003, design report." / Chapter I. --- Introduction --- p.p.1 / Chapter II. --- Research - Flyover and Urbanism --- p.p.2 / Chapter i. --- Typology Definition --- p.p.3 / Chapter ´Ø --- Type 1 - Living with Flyover --- p.p.4-5 / Chapter ´Ø --- Type 2 - Flyover and Open Space --- p.p.6-7 / Chapter ´Ø --- Type 3 - Flyover as Transition --- p.p.8-9 / Chapter ´Ø --- Type 4 - Flyover as Generator --- p.p.10-11 / Chapter ´Ø --- Type 5 - Flyover and Water --- p.p.12-13 / Chapter ´Ø --- Type 6 - Flyover as Place --- p.p.14-15 / Chapter ii. --- Research Main Body --- p.p.16 / Introduction --- p.P.17 / Pedestrians' Perspective --- p.p.18 / Chapter ´Ø --- Overview --- p.p.19-22 / Chapter ´Ø --- Open Spaces under Flyovers --- p.p.23-26 / Chapter ´Ø --- Structures under Flyovers --- p.p.27-30 / Residents' Perspective --- p.p.31 / Chapter ´Ø --- Impact of flyovers to residents --- p.p.32-33 / Chapter ´Ø --- Building type within city grid --- p.p.34 / Chapter ´Ø --- New housing design in response to Flyovers --- p.p.35 / Drivers' Perspective --- p.p.36 / Chapter ´Ø --- View on Flyovers --- p.p.37-46 / Chapter ´Ø --- Spatial Experience --- p.p.47-48 / Chapter ´Ø --- Visual Experience --- p.p.49-50 / Chapter iii. --- Precedent Study --- p.p.51-58 / Chapter III. --- Design - Colonizing Highways --- p.p.59 / Chapter i. --- Design Statement --- p.p.60 / Chapter ii. --- Issues of Roundabouts in Hong Kong --- p.p.61-62 / Chapter iii. --- Site Analysis --- p.p.63-67 / Chapter iv. --- Design / Chapter ´Ø --- A New Order - Massing Study --- p.p.68-70 / Chapter ´Ø --- Sectional Organization --- p.p.71-73 / Chapter ´Ø --- Planning Organization --- p.p.74-75 / Chapter ´Ø --- Residential Units --- p.p.76-77 / Chapter ´Ø --- Facade Design --- p.p.78 / Chapter ´Ø --- Ground Plane Design --- p.p.79-81 / Chapter v. --- Appendix / Chapter ´Ø --- Section A-A' --- p.p.82 / Chapter ´Ø --- Section B-B' --- p.p.83 / Chapter ´Ø --- Section C-C' --- p.p.84 / Chapter ´Ø --- Elevation --- p.p.85-87 / Chapter ´Ø --- Balcony detail --- p.p.88 / Chapter ´Ø --- Kitchen wall and floor detail --- p.p.89

Wong Yeuk Hay. / "Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2002-2003, design report." / Chapter I. --- Introduction --- p.p.1 / Chapter II. --- Research - Flyover and Urbanism --- p.p.2 / Chapter i. --- Typology Definition --- p.p.3 / Chapter ´Ø --- Type 1 - Living with Flyover --- p.p.4-5 / Chapter ´Ø --- Type 2 - Flyover and Open Space --- p.p.6-7 / Chapter ´Ø --- Type 3 - Flyover as Transition --- p.p.8-9 / Chapter ´Ø --- Type 4 - Flyover as Generator --- p.p.10-11 / Chapter ´Ø --- Type 5 - Flyover and Water --- p.p.12-13 / Chapter ´Ø --- Type 6 - Flyover as Place --- p.p.14-15 / Chapter ii. --- Research Main Body --- p.p.16 / Introduction --- p.p.17 / Pedestrians' Perspective --- p.p.18 / Chapter ´Ø --- Overview --- p.p.19-22 / Chapter ´Ø --- Open Spaces under Flyovers --- p.p.23-26 / Chapter ´Ø --- Structures under Flyovers --- p.p.27-30 / Residents' Perspective --- p.p.31 / Chapter ´Ø --- Impact of flyovers to residents --- p.p.32-33 / Chapter ´Ø --- Building type within city grid --- p.p.34 / Chapter ´Ø --- New housing design in response to Flyovers --- p.p.35 / Drivers' Perspective --- p.p.36 / Chapter ´Ø --- View on Flyovers --- p.p.37-46 / Chapter ´Ø --- Spatial Experience --- p.p.47-48 / Chapter ´Ø --- Visual Experience --- p.p.49-50 / Chapter iii. --- Precedent Study --- p.p.51-58 / Chapter III. --- Design - Reweaving the New & Old Urban Fabrics --- p.p.59 / Chapter i. --- Introduction --- p.p.60 / Chapter ii. --- Site Analysis --- p.p.61-65 / Chapter iii. --- Urban Design Strategies --- p.p.66-67 / Chapter iv. --- Final Design - Civic Bridge / Chapter ´Ø --- Conceptual diagrams --- p.p.68-69 / Chapter ´Ø --- Plans --- p.p.70-72 / Chapter ´Ø --- Elevations and Sections --- p.p.73-75 / Chapter ´Ø --- Perspective --- p.p.76-77 / Chapter ´Ø --- Photos --- p.p.78-79

Geologists have indicated that the question is not if a catastrophic earthquake will occur in Oregon but when one will occur. Scientists estimate that there is close to 40 percent conditional probability that a Cascadia subduction zone earthquake of magnitude 8.0 or above will strike Oregon in the next 50 years. In addition, the majority of Oregon's bridge inventory was built prior to the current understanding of bridge response and prior to current understanding of the expected earthquake demands. In order to minimize potential bridge damage in the case of an earthquake, one approach is to retrofit seismically deficient bridges. However, often times the decision maker is faced with the difficulty of selecting only a few bridges within the inadequate ones. Hence, the issue of prioritizing upgrading naturally arises. The goal of this study is to assess and refine bridge prioritization methodology to be utilized for ranking Oregon's bridge inventory. CFRP retrofit has been experimentally and analytically evaluated to demonstrate the effectiveness of the technique and was found to be an efficient and economical option. A vulnerability assessment estimates that close to 30 percent of Oregon's highway bridge inventory will sustain moderate damage to collapse. However, retrofitting two most common bridge types in the inventory will reduce the number of damaged bridges by about 70 percent. A cost-benefit assessment that takes into consideration direct and indirect costs associated with damaged bridges and retrofitting of bridges shows that the benefit is up to three times the cost to retrofit. The same principle was applied to rank twelve highway segments for seismic retrofit considered important by Oregon Department of Transportation. One selected segment was considered to be retrofitted and vulnerability assessed. The benefit to cost ratios for each assessment was compared and the highway segments were ranked accordingly. The top five segments in the ranking happen to be located in the East-West corridor connecting I-5 to US-101.

A large magnitude, long duration subduction earthquake is impending in the Pacific Northwest, which lies near the Cascadia Subduction Zone (CSZ). Great subduction zone earthquakes are the largest earthquakes in the world and are the sole source zones that can produce earthquakes greater than M8.5. Additionally, the increased duration of a CSZ earthquake may result in more structural damage than expected. Given such seismic hazard, the assessment of reinforced concrete substructures has become crucial in order to prioritize the bridges that may need to be retrofitted and to maintain the highway network operable after a major seismic event. Recent long duration subduction earthquakes occurred in Maule, Chile (Mw 8.8, 2010) and Tohoku, Japan (Mw 9.0, 2011) are a reminder of the importance of studying the effect of subduction ground motions on structural performance. For this purpose, the seismic performance of substandard circular reinforced concrete bridge columns was experimentally evaluated using shake table tests by comparing the column response from crustal and subduction ground motions. Three continuous reinforced columns and three lap-spliced columns were tested using records from 1989 Loma Prieta, 2010 Maule and 2011 Tohoku. The results of the large-scale experiments and numerical studies demonstrated that the increased duration of subduction ground motions affects the displacement capacity and can influence the failure mode of bridge columns. Furthermore, more damage was recorded under the subduction ground motions as compared to similar maximum deformations under the crustal ground motion. The larger number of plastic strain cycles imposed by subduction ground motions influence occurrence of reinforcement bar buckling at lower displacement compared to crustal ground motions. Moreover, based on the experimental and numerical results, subduction zone ground motion effects are considered to have a significant effect on the performance of bridge columns. Therefore, it is recommended to consider the effects of subduction zone earthquakes in the performance assessment of substandard bridges, or when choosing ground motions for nonlinear time-history analysis, especially in regions prone to subduction zone mega earthquakes. Finally, for substandard bridges not yet retrofitted or upgraded seismically, the following performance limit recommendation is proposed: for the damage state of collapse, which is related to the ODOT's Life Safety performance level, the maximum strain in the longitudinal reinforcement should be reduced from 0.09 (in./in.) to a value of 0.032 (in./in.) for locations where subduction zone earthquakes are expected, to take into consideration the occurrence of bar buckling.

Thesis (Ph. D.)--Florida State University, 2005. / Includes bibliographical references (p. 175-176). Also available online via the Florida State University electronic theses website (http://etd.lib.fsu.edu/).