No description available.

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The X-ray computed tomography is a technology to investigate air void structure of drilled asphalt cores, which provides a non-destructive alternative to traditional laboratory methods, usually destructive testing.In this work, six in-situ specimens from a double layer porous asphalt pavement in Linköping, Sweden, were taken and analysed using both qualitative and quantitative methods of tomography. The qualitative study focused on identifying different features of the drilled cores, such as densification and air voids in the interface between the two porous layers. In the quantitative study, the air voids contents were quantified from processed tomography images. The tomography results of air voids content in all three directions (X, Y and Z), when increasing the calculated number of slices from 4 to 8, were compared to the measured air voids contents from a standardized laboratory method. Both t-test and F-test were applied to determine if a significant difference was found. Besides, the Evaluation Index (EI) was introduced to determine the most accurate combination slices and directions.The results shown here indicate that a reduced number of tomography slices can give enough accuracy in the determination of air voids content for the porous layers. The results also showed that air voids content determined with tomography gave no significant difference compared to the laboratory results. The most accurate combination found was, in this case, the Y+Z direction. Future development will focus on automatizing the determination of air voids, as well as mastic and aggregate phases using the same methodology of comparing tomography results with laboratory results.

Approved for public release, distribution is unlimited / Resonant excitation tests of rotor blades in vacuum spin pits using discrete oil jets showed that impact erosion of the blades could limit test times, but lower excitation amplitudes were produced using mist nozzles. Smaller diameter discrete jets might extend test times, but to fully prevent erosion, oil mist droplet size needed to be 30 microns or less. The present study examined both approaches. Prototype nozzles were developed to create 0.005 inch diameter multiple discrete jets using first alumina, then stainless steel tubing, laser and micro-machine drilling. The latter technique was selected and 50 were manufactured for evaluation in HCF spin tests. A vacuum test chamber was built to observe and photograph spray patterns from the prototype nozzles and from commercially available mist nozzles. An LDV system was used successfully to determine the velocity of the oil droplets within the mist. A complete mapping of mist nozzle sprays is required to allow routine design of blade excitation systems. / Lieutenant, United States Navy

Drilled shaft retaining walls are common earth retaining structures, well suited to urban environments where noise, space, and damage to adjacent structures are major considerations. The design of drilled shaft retaining walls in non-expansive soils is well established. In expansive soils, however, there is no consensus on the correct way to account for the influence of soil expansion on wall behavior. Based on the range of design assumptions currently in practice, existing walls could be substantially over- or under-designed. The goal of this research is to advance the understanding of the effects of expansive clay on drilled shaft retaining walls. The main objectives of this study are to identify the processes responsible for wall loading and deformation in expansive clay, to evaluate how these processes change with time, and to provide guidance for design practice to account for these processes and ensure adequate wall performance. The primary source of information for this research is performance data from a four-year monitoring program at the Lymon C. Reese research wall, a full-scale instrumented drilled shaft retaining wall constructed through expansive clay in Manor, Texas. The test wall was instrumented with inclinometers and fiber optic strain gauges, and performance data was recorded during construction, excavation, during natural moisture fluctuations, and during controlled inundation tests that provided the retained soil with unlimited access to water. In addition to the test wall study, a field assessment of existing TxDOT drilled shaft retaining walls was conducted. The main process influencing short-term wall deformation was found to be global response to stress relief during excavation, which causes the wall and soil to move together without the development of large earth pressures or bending stresses. Long-term wall deformations were governed by the development of drained conditions in both the retained soil and the foundation soil after approximately eight months of controlled inundation testing. To ensure adequate wall performance, the deformations and structural loads associated with short- and long-term conditions should be combined and checked against allowable values. / text

Abstract This thesis has shown that the development of the instrumentation necessary to provide in-situ thermal imaging for the determination of homogeneity of concrete is theoretically sound. Drilled shafts are large diameter underground cast-in-place columns that necessarily rely on sound integrity to properly withstand imposed loadings. As a by-product of the most common construction techniques, the entire process is often completely blind whereby the excavation and concreting processes are conducted beneath the surface of the water table (or slurry level). This results in an inability to inspect the final product and in many cases allows anomalous inclusions (soil cave-ins, slurry pockets, etc) to go undetected especially when they are formed outside the steel reinforcing cage. In an effort to gain verification of the as-built, below ground structure, numerous non-destructive test methods have been devised. Each of these methods have merits and drawbacks with regards to the full extent of the tested concrete volume. To further this cause, a new methodology was developed that uses the energy from hydrating concrete to assess the presence or absence of an intact concrete. Therein, the temperature generated by the curing concrete can be measured and correlated to the probable dimensions of the drilled shaft. This thesis outlines the development of the instrumentation capable of making in-situ temperature measurement of drilled shafts to assure the homogeneity of concrete is acceptable. To that end, several configurations of instrumentation approach were tested on varying scales from small lab specimens to full-size field constructed drilled shafts. The bulk of this work was conducted several years before the completion of the thesis and has the benefit of noting later developments. For instance, this study was used to seed future research and led to subsequent FDOT and WSDOT (Washington State DOT) funded research for the express purpose of identifying capabilities of thermal testing in those states. Likewise, present day practice and use of the approach has also been documented.

In the process of drilling, the rock fragments generated by the drill are taken from the well to the surface by the drilling fluid. The drilling fluid used in Brazil is made by synthetic oil, it presents several advantages over other types of drilling fluid. However, it has the disadvantage of having high toxicity and low biodegradability, requiring a separation system of drilled cuttings contaminated with this drilling fluid. Currently, the responsible equipment for reducing these levels to the permitted by law is working under extreme conditions and residual levels generated are very close to permitted by environmental legislation. For this reason, the technique of microwave drying has been studied for use in remediation of drilled cuttings and has shown very promising because it presents high efficiency and low operational problems when it is compared to conventional equipment. Therefore, the aim of this work are to investigate the influence of various operating parameters of a microwave dryer, analyze the efficiency of the dryer microwave suited for this job and to obtain operational conditions and information for operating a industrial microwave operating in continuous flow. So were tested influence of temperature, flow rate of inert, initial fluid content, reuse of drilled cuttings, rock type, fluid type and mechanical agitation in microwave drying; tests of drying kinetics and the mapping drying inside the microwave were made. The results showed no difference in drying with the influence of inert flow and the type of fluid, but there was influence of drying temperature, the initial salt content, initial fluid content and rock type. Drying with agitation can increased the removal efficiency in 17 % with 27 mm of bed thickness, rocks with slow heating improve the removal efficiency, drilled cuttings with similar physical aspects have similar removal efficiency. The heating of rocks in the microwave depends strongly of the oxides content in its composition. The temperature control of the bed should be the upper limit of the boiling range of the hydrocarbons present in the drilling fluid. The mapping study showed that there are drying gradients inside the microwave, besides showing the intrusive effect of metals in the material, effect of the edges of the recipes and the position of exhaust fan. The equipment showed to be as efficient as others listed in the literature, which can reduce the levels of n-paraffin to below 1 % by mass. / No processo de perfuração de poços de petróleo, os fragmentos de rocha gerados pela broca, são transportados do fundo do poço até a superfície pelo fluido de perfuração. O fluido de perfuração mais utilizado no cenário brasileiro é o de base sintética, pois apresenta diversas vantagens com relação a outros tipos de fluido. Porém, apresenta a desvantagem de possuir alta toxicidade e baixa biodegrabilidade, necessitando de um sistema de separação para que o cascalho contaminado com esse fluido possa ser descartado no meio ambiente. Atualmente, o equipamento responsável pela redução destes teores até os limites permitidos por lei, opera de maneira sobrecarregada e os teores residuais alcançados estão muito próximos do permitido pela legislação ambiental. Por essa razão, a técnica de secagem por micro-ondas vem sendo estudada para ser utilizada na descontaminação de cascalhos contaminados com fluido de perfuração. Essa tecnologia mostra-se ser muito promissora, pois apresenta altas eficiências de remoção e menores problemas operacionais quando comparados aos equipamentos convencionais. Por isso, o objetivo deste trabalho é verificar a influência de algumas variáveis de operação de um secador micro-ondas de bancada adaptado para a descontaminação de cascalhos de perfuração. Além de verificar a eficiência desse equipamento e obter condições operacionais e informações suficientes para o projeto de um micro-ondas semi-industrial contínuo. Para isso, foram testadas as influências da temperatura, vazão de inerte, teor inicial de fluido, reutilização do cascalho, tipo de rocha, tipo de fluido e a presença da agitação mecânica na secagem por micro-ondas; foram feitos testes de cinética de secagem por micro-ondas e feito o mapeamento da secagem no interior do equipamento. Os resultados mostraram que não houve diferença na secagem por micro-ondas para diferentes vazões de inerte e tipo de fluido, porém houve influência da temperatura da secagem, do teor inicial de sal, do teor inicial de fluido e do tipo de rocha. A agitação mecânica aumentou a eficiência de remoção em 17% para um leito de 27 mm de espessura; o aquecimento lento de cascalhos melhoram a eficiência de remoção; cascalhos contaminados que apresentam aspectos físicos iguais apresentam eficiência de remoção semelhantes. O aquecimento de rochas no micro-ondas depende, fortemente, dos teores de óxidos em sua composição. A temperatura de controle do leito deve ser acima do limite superior da faixa de ebulição dos hidrocarbonetos presentes na base do fluido de perfuração. O estudo de mapeamento mostrou que há gradientes de secagem no interior do micro-ondas, além de mostrar o efeito intrusivo de metais no material e efeito das bordas do recipiente. O equipamento apresentou ser tão eficiente quanto outros reportados na literatura, podendo reduzir os teores de n-parafina até abaixo de 1%, em massa. / Mestre em Engenharia Química

The diploma thesis deals with the construction technological project of a self-service shopping centre in Stará Plesná village. Time and finance plan, design of machinery and project of building site accessories were elaborated. The work is focused on the main building object SO 101 (Shopping and service centre). For this building pile foundations and top coarse building phase were worked out in greater details. Time plan, item budget and other documents concerning building preparations of object SO 101 are also parts of the work.

No description available.

<p>The research contained in this thesis is concerned with longterm behaviour of drilled piers socketed in weak rock. The experimental work involved testing of two steel and seven concrete model piers. The 25.4 mm (1.0 in) diameter steel piers had relatively smooth socket walls (RF = 0.033) and were socketed into pseudo-rock material. The concrete piers were 76.2 mm (3.0 in) in diameter and were socketed into weak rock (Queenston Shale). The concrete piers were of two types: conventional socketed piers with relatively smooth socket walls (RF = 0.025) and grooved piers with relatively rough socket walls (RF = 0.081 and 0.303).</p> <p>The piers were tested under two condition of load support, shaft resistance only and combined shaft resistance and end-bearing support conditions.</p> <p>In case of steel piers, electrical resistance strain gauges were mounted on the pier shaft to measure the load distribution along the shaft of the piers. For concrete piers under combined shaft resistance and end-bearing support conditions, flat jack load cells with Marsh and Budenberg pressure gauges and/or electrical pressure transducers were used to measure the load transfer at the base.</p> <p>All model piers were axially loaded in the laboratory using load frames designed and fabricated for this purpose. The axial loads were iii applied by the air cylinders and held constant throughout the period of testing using a regulated air pressure supply.</p> <p>The test results confirmed that performance of socketed piers can be significantly improved by increasing the roughness of the pier-rock interface. Both the primary creep rate and the load transfer with time were larger for piers with small shaft roughness.</p> <p>A second stage of creep having a much lower creep rate was observed for all model tests. The time to the end of primary creep was found to depend on the roughness of the socket wall. The primary and secondary creep rate appeared to be dependent on the stress level, shaft roughness, compressive strength of weak rock and support conditions.</p> <p>The results of the model tests are compared with available test data and with values predicted using methods based on viscoelastic analysis. This method of analysis for piles in clay soils has been modified for application to socket piers in weak rock. It is suggested that the modifications can be used to estimate the long-term settlement of socket piers in weak rock</p> / Master of Engineering (ME)