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In a world with unlimited travel options, railways play a key role in transportation. In order to serve the demand at a satisfactory level, it is important that the infrastructure quality remains high and safe. Maintenance is then the most important aspect of railway infrastructure.  This project’s aim is to develop a tool that would evaluate the cost differences and maintenance needs during the life cycle of turnouts, bent with different radii to straight, as a crucial part of the infrastructure, not only technically but also financially. When the cost over a life cycle is provided then design decisions can get more efficient.  Maintenance history of seven years of preventive and corrective maintenance data from databases Bessy and 0felia for single turnouts across the Swedish rail network were studied, analysed and evaluated.  Along with information from interviews with key informants the cost driving parameters were specified. The calculator was developed in Microsoft Excel, giving results for bent turnouts in 4 different radii categories and the respective straight turnouts. An EV-UIC60-760-1:14 turnout was used as a case study for different radii categories and 3 different scenarios were run in order to test the robustness of the tool.  The results showed that bent turnouts have a higher life cycle cost than straight in the order of 1 to 3 mkr depending on the radius, the bigger share of which is usually the preventive maintenance cost, with the specifics to vary between the categories and different scenarios tested. The way maintenance data are registered and classified plays an important role in the analysis.

Several reinforced concrete bent caps (deep beams) in Texas have developed significant diagonal cracks in service. The cracking in two bent caps was so extensive that costly retrofits were implemented to strengthen the structures. Strut-and-tie modeling is currently recommended in most U.S. design specifications for the design of reinforced concrete bent caps and deep beams. Designers have expressed concerns with the lack of clarity and serviceability-related considerations in strut-and-tie model design provisions. Due to concerns with strut-and-tie modeling design provisions and field problems of in-service bent caps, TxDOT Project 5253 was funded. Several tasks conducted within Project 5253 are addressed in this dissertation. The effects of minimum web reinforcement and member depth on the strength and serviceability behavior of deep beams are presented. The transition between deep beam shear capacity and sectional shear capacity near a shear-span-to-depth (a/d) ratio of 2 is addressed. A service-load shear check to limit diagonal cracking in service is outlined. Lastly, a simple chart that correlates the maximum width of diagonal cracks in a deep beam to its residual capacity is developed. To accomplish the objectives of Project 5253, thirty-seven tests were conducted on reinforced concrete beams with the following cross-sectional dimensions: 21”x23”, 21”x42”, 21”x44”, 21”x75”, and 36”x48.” The specimens were loaded with a/d ratios of 1.2, 1.85, and 2.5. The test specimens are among the largest reinforced concrete deep beams in the literature. To supplement the findings of the experimental program, a database of deep beam test results was compiled. Entries in the database that lacked sufficient information and that did not meet established cross-sectional size or web reinforcement criteria were filtered from the database. The use of the database in conjunction with the experimental program enabled each objective to be addressed from both broad and specific viewpoints. Several recommendations for improving the strength and serviceability design of deep beams are presented including a minimum web reinforcement requirement, provisions to ease the transition between calculated deep beam and sectional shear capacity, and a design check to limit diagonal cracking in service. / text

Después de recopilar brevemente la historia de las funciones bent a lo largo de estas últimas cuatro décadas y recopilar los resultados preliminares necesarios para la comprensión y entendimiento de la notación utilizada, se demuestran una serie de propiedades del grado de las funciones booleanas y se construyen algoritmos basados en ellas, útiles para determinar computacionalmente el grado partiendo del soporte o tabla de verdad que define a la función. También se presentan construcciones de funciones de no linealidad perfecta teniendo como punto de partida bases de un espacio vectorial sobre el cuerpo de Galois. Por último, se introducen construcciones de una clase especial de funciones de no linealidad perfecta, conocidas como Partial Spread, planteando una serie de cuestiones abiertas que merecería la pena investigar en el futuro.

Current seismic design approach of bridge structures can be categorized into two distinctive methods: (i) force based and (ii) performance based. AASHTO LRFD seismic design specification is a typical example of force based design approach especially used in Turkey. Three different importance categories are presented as &ldquo / Critical Bridges&rdquo / , &ldquo / Essential Bridges&rdquo / and &ldquo / Other Bridges&rdquo / in AASHTO LRFD. These classifications are mainly based on the serviceability requirement of bridges after a design earthquake. The bridge&rsquo / s overall performance during a given seismic event cannot be clearly described. Serviceability requirements specified for a given importance category are assumed to be assured by using different response modification factors. Although response modification factor is directly related with strength provided to resisting column, it might be correlated with selected performance levels including different engineering response measures. Within the scope of this study, 27216 single circular bridge column bent models designed according to AASHTO LRFD and having varying column aspect ratio, column diameter, axial load ratio, response modification factor and elastic design spectrum data are investigated through a series of analyses such as response spectrum analysis and push-over analysis. Three performance levels such as &ldquo / Fully Functional&rdquo / , &ldquo / Operational&rdquo / and &ldquo / Delayed Operational&rdquo / are defined in which their criteria are selected in terms of column drift measure corresponding to several damage states obtained from column tests. Using the results of analyses, performance categorization of single bridge column bents is conducted. Seismic responses of investigated cases are identified with several measures such as capacity over inelastic demand displacement and response modification factor.