Lightweight cellular concrete (LCC) is a cement, water, and air entrained mixture that consists of 25-80% voids. The air voids reduce the material strength but also decrease the material weight. Due to its lightweight properties LCC is an attractive alternative to soil backfill for retained structures, such as mechanically stabilized earth (MSE) walls. Although LCC is widely used behind MSE walls, limited information exists regarding the pullout strength of MSE wall reinforcements in LCC backfill. This research attempts to fill the knowledge gap through performing pullout tests on welded wire and ribbed strip reinforcements in MSE walls to determine the pullout friction coefficient (F*), reinforcement pullout behavior, and LCC properties. A large-scale test box (10 feet wide x 12 feet long x 10 feet high) supported by a steel resisting frame, was constructed, and filled with LCC backfill. Both the west and east MSE wall faces consisted of concrete walls. The west wall was supported by 16 ribbed strip reinforcements, while the east wall was supported by nine short, welded wire reinforcements. After backfilling the MSE wall, pullout tests were performed of the 12 ribbed strip reinforcements and all nine welded wire reinforcements. To determine different pullout friction coefficients (F*), different surcharge loads were applied through LCC self-weight, concrete reaction beams, and hydraulic jacks at the top of backfill. After performing the pullout tests on the large-scale test box, additional pullout tests were performed in two smaller (10 feet wide x 6 feet deep x 30 in. tall) MSE walls, each containing four ribbed strip reinforcements to determine the F* of ribbed strip reinforcements at moderate surcharge pressures. Results from these tests produced F* recommendations for ribbed strip and welded wire reinforcements. Additionally, a total of 130 LCC cylinder specimens were used to identify LCC material properties. Results of these tests show that the unconfined compressive strength of LCC is greatly dependent on the cast and cured unit weight, as well as the sample maturity. Comparing the UCS results to other work reveals a wide variation of UCS versus cured density, even though the same ASTM standard was applied for all tests. An equation for the secant modulus of LCC was created using UCS data from this thesis and other research conducted at Brigham Young University (BYU). Direct shear tests were also conducted on LCC cylinders cut to fit the confinement of a direct shear machine. The direct shear test results from this thesis agree with other research conducted at BYU.

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The advantages of Integral Abutment Bridges (IABs) include reduced maintenance costs and increased useful life spans. However, comprehensive and practical analysis tools for design of IABs have not been developed to account for the impacts of thermal displacements on abutment and foundation components, including the components of mechanically stabilized earth (MSE) walls that are often used around the abutment piling. During this research, over 65 three-dimensional numerical analyses were performed to investigate and quantify how different structural and geotechnical bridge components behave during thermal expansion and contraction of the bridge deck. In addition, separate three-dimensional numerical models were developed to evaluate the usefulness of corrugated steel pipes around the abutment piles. The results of this research quantify the influence of design parameter variations on the effects of thermal displacement on system components, and thus provide guidelines for IAB design, where none had existed before. One of the findings is that corrugated steel pipes around abutment piles are not necessary. One of the most important products of this research is an easy-to-use Excel spreadsheet, named IAB v2, that not only quantifies the impact of thermal displacement in the longitudinal direction, but also in the transverse direction when the abutment wall is at a skew angle to the bridge alignment. The spreadsheet accommodates seven different pile sizes, which can be oriented in weak or strong directions, with variable offset of the abutment from the MSE wall and for variable skew angles. The spreadsheet calculates the increment of displacements, forces, moments, and pressures on systems components due to thermal displacement of IABs. / Ph. D.

The least mean square (LMS) algorithm is widely expected to operate near the corresponding Wiener filter solution. An exception to this popular perception occurs when the algorithm is used to adapt a transversal equalizer in the presence of additive narrowband interference. The steady-state LMS equalizer behavior does not correspond to that of the fixed Wiener equalizer: the mean of its weights is different from the Wiener weights, and its mean squared error (MSE) performance may be significantly better than the Wiener performance. The contributions of this study serve to better understand this so-called non-Wiener phenomenon of the LMS and normalized LMS adaptive transversal equalizers. The first contribution is the analysis of the mean of the LMS weights in steady state, assuming a large interference-to-signal ratio (ISR). The analysis is based on the Butterweck expansion of the weight update equation. The equalization problem is transformed to an equivalent interference estimation problem to make the analysis of the Butterweck expansion tractable. The analytical results are valid for all step-sizes. Simulation results are included to support the analytical results and show that the analytical results predict the simulation results very well, over a wide range of ISR. The second contribution is the new MSE estimator based on the expression for the mean of the LMS equalizer weight vector. The new estimator shows vast improvement over the Reuter-Zeidler MSE estimator. For the development of the new MSE estimator, the transfer function approximation of the LMS algorithm is generalized for the steady-state analysis of the LMS algorithm. This generalization also revealed the cause of the breakdown of the MSE estimators when the interference is not strong, as the assumption that the variation of the weight vector around its mean is small relative to the mean of the weight vector itself. Both the expression for the mean of the weight vector and for the MSE estimator are analyzed for the LMS algorithm at first. The results are then extended to the normalized LMS algorithm by the simple means of adaptation step-size redefinition. / Ph. D.

Lightweight cellular concrete (LCC) is a type of concrete that has reduced density and weight compared to traditional concrete. This is achieved by incorporating a large amount of air- filled cells or voids into the mixture. The resulting material is lighter, yet still possesses considerable strength and durability, making it suitable for a range of construction applications, especially in the case of retaining walls because of its reduced weight. Unlike traditional concrete, which can be extremely heavy and place significant stress on the supporting structure, lightweight cellular concrete reduces the pressure on the retaining wall, helping to prevent deformation and failure. Additionally, the reduced weight of the material can also simplify construction processes and make it easier to transport and handle, reducing the cost and labor required to build a retaining wall. The reduced weight also makes it possible to build taller walls with less settlement in the underlying compressible layers, which can be especially beneficial in areas with utility lines sensitive to displacement. Despite these advantages, limited research has been performed on the use of LCC as a backfill for retaining wall applications. This report provides new test data on the pullout resistance of ribbed-strip and welded-wire mesh reinforcements at high pressures. The pullout tests at high pressures were conducted in which four test prisms (2 ft wide x 10 ft long x 2' tall) that were filled with LCC with welded-wire mesh reinforcement on one side and ribbed strip reinforcement on the other. These boxes were loaded with vertical confining pressures of 40, 50, and 60 psi and subjected to a pullout force on the reinforcement until failure. These results were then combined with results from previous BYU tests at lower pressures to define pullout resistance factors, F* (friction coefficients) for MSE reinforcements over a full range of pressures. Finally, the pullout resistance of MSE reinforcements were used in slope stability models to back-calculate the F* values that would lead to failure at the surcharge pressures measured in three previous large-scale tests conducted on 10 ft wide x 10 ft tall x 13 ft long blocks of LCC at BYU. Very good agreement was obtained between the computed F* at failure and the measured F* values confirming the validity of this approach for engineering design in the future involving global stability MSE wall stability under surcharge loading.

Porttelefoner används ofta i högljudda miljöer. Ett exempel på en sådan miljö är vindutsatta områden, där operatören i ett rum kan uppleva svårigheter att uppfatta tal från användaren som talar i en porttelefon på grund av den omgivande höga ljudnivån. Många porttelefoner och andra liknande enheter stöter vanligtvis på utmaningar och begränsningar, särskilt när det gäller snabbhet, storlek, resurshantering och hantering av dynamiska signaler.  Detta projekt genomfördes vid ett svenskt företag inom nätverksbaserade lösningar för videoövervakning och fysisk säkerhet. Projektet syftar till att utforska och implementera ett adaptiv filter med en adaptiv algoritm i C-programmering för att komplettera ett digitalt signalbehandlingssystem som en strategi för att förbättra ljudkvaliteten genom att reducera bruset hos porttelefoner i utmanande miljöer. Genom att tillämpa ett lämpligt adaptiv filter i en Raspberry Pi för att simulera en porttelefon, strävar projektet efter att reducera brus och optimera talet. Några av de vanligaste filtreringsalgoritmerna som använts i tidigare forskning för att förbättra ljudkvaliteten är Least mean square, Normalized least mean square och Recursive least square som även utvärderas i denna studie. Efter noggranna studier valdes algoritmen Normalized least mean square för implementering i detta projekt. Algoritmens prestanda utvärderas med hjälp av beräkningstiden, medelkvadratfelet och signal-till-brus-förhållandet i Matlab samt användartester för att säkerställa kvaliteten. Detta projekt uppnådde målen genom att utveckla ett fungerande adaptivt filter. Det rekommenderas att implementera filtret i en porttelefon där mikrofonerna inte är placerade nära varandra för att förhindra upptagning av dubbla liknande signaler. Under projektets gång hanterade systemet kontinuerligt dataströmmar effektivt i praktiska tester, vilket bekräftade att det fungerade utan fördröjningar. Detta bevisade det adaptiva filtrets effektivitet i verkliga applikationer, särskilt i högljudda miljöer. / Intercoms are often used in noisy environments. An example of such an environment is windy areas, where the operator inside a room may find it difficult to perceive speech from a user speaking through an intercom due to the surrounding high noise levels. Many intercoms and other similar devices typically encounter challenges and limitations, especially in terms of speed, size, resource management, and handling of dynamic signals. This project was carried out at a Swedish company specializing in network-based solutions for video surveillance and physical security. The project’s objective was to study and implement an adaptive filter with an adaptive algorithm in C programming to complement a digital signal processing system, as a strategy to enhance sound quality by reducing noise in intercoms in challenging environments. By applying a suitable adaptive filter in a Raspberry Pi to simulate an intercom, the goal of the project is to reduce noise and optimize speech clarity. Some of the most common filtering algorithms used in previous research to improve sound quality include Least mean square, Normalized least mean square och Recursive least square, which are evaluated in this study. After thorough studies, the Normalized least mean square algorithm was selected for implementation in this project. The performance of the algorithm is assessed using computation time, mean squared error, and signal-to-noise ratio in Matlab, along with user testing to ensure quality. This project achieved its goals by developing a functional adaptive filter. It is recommended to implement the filter in an intercom where the microphones are not placed close to each other to prevent the capture of similar duplicate signals. Throughout the project, the system continuously handled data streams effectively in practical tests, confirming that it operated without delays. This demonstrated the adaptive filter's effectiveness in real applications, particularly in noisy environments.

El presente trabajo de investigación tuvo como objetivo principal, evaluar el comportamiento mecánico de un suelo arcilloso de la localidad de Pacaisapa – Ayacucho utilizando residuos industriales como el caucho molido, proveniente de llantas reciclada, tiras de plástico reciclado y ceniza de cáscara de arroz aplicado estás mezclas en un muro de tierra hipotético estabilizado mecánicamente (MSE). La metodología de esta investigación consistió en realizar ensayos de corte directo NTP-339.171 y ensayos de compresión no confinada NTP-339.167 con la finalidad de obtener los parámetros de cohesión, ángulo de fricción y módulo de elasticidad del suelo. Los mismos que se utilizarán para evaluar el comportamiento de estás mezclas en el muro hipotético y modelado en el software Plaxis 8.2 haciendo uso del modelo constitutivo Mohr-Coulomb. Las combinaciones que se utilizaron fueron 30% ceniza de cáscara de arroz, 2% de PET y 10% de caucho. Los resultados obtenidos indicaron que la cohesión mejora en un 41.89% con la adición de un 30% de ceniza de cáscara de arroz y en 21.58% con la adición de 2% de tiras de plástico reciclado respecto al suelo S100, mejora el módulo de elasticidad cuando de agrega 2% de tiras de plástico en 28.78% y cuando se agrega 30% de ceniza de cáscara de arroz (CCA) mejora en 4.8% respecto al suelo puro. Además, los desplazamientos horizontales de la cara vertical del muro disminuyen al utilizar la mezcla 1 – S70CC30 y la mezcla 3 - S98P2, respecto al suelo S100. En base a lo que permite concluir que la adición de PET y CCA sí mejora el comportamiento mecánico del suelo y es posible optimizar la separación entre los geosintéticos. / The main objective of this research was to evaluate the mechanical behavior of a clay soil in the town of Pacaisapa - Ayacucho using industrial waste such as ground rubber from recycled tires, recycled plastic strips and rice husk ash applied to these mixtures in a mechanically stabilized hypothetical earth wall (MSE). The methodology of this investigation consisted in performing direct cutting tests NTP-339.171 and unconfined compression tests NTP-339.167 in order to obtain the parameters of cohesion, friction angle and young modulus of elasticity of the soil. The same ones that will be used to evaluate the behavior of these mixtures in the hypothetical wall and modeled in the Plaxis 8.2 software making use of the Mohr-Coulomb constitutive model. The combinations that were used were 30% rice husk ash, 2% PET and 10% rubber. The obtained results indicated that the cohesion improves in a 41.89% with the addition of 30% of rice husk ash and in 21.58% with the addition of 2% of recycled plastic strips with respect to the S100 soil, improves the modulus of elasticity when it adds 2% of plastic strips in 28.78% and when 30% of rice husk ash (CCA) is added it improves in 4.8% with respect to the pure soil. In addition, the horizontal displacements of the vertical face of the wall decrease when using the mixture 1 - S70CC30 and the mixture 3 - S98P2, with respect to the floor S100. Based on what allows concluding that the addition of PET and CCA does improve the mechanical behavior of the soil and it is possible to optimize the separation between the geosynthetics. / Tesis

The transformation of the world economy that brought the collapse of borders and trade barriers brought a setting conducive to the prosperity of large corporations, while small and medium enterprises have gained additional difficulties to remain in operation. However, with the emergence of collaborative networks of small and medium enterprises through its membership in collaborative networks had the opportunity to reposition itself to face this new scenario. Particularly, the neighborhood grocery, which falls within that context might get to compete against the big hypermarket chains that have proliferated in this environment. With this thesis developed, it was through a case study to identify the factors of competitiveness achieved by a network of supermarkets in operation for over 10 years in local market. Were observed and pointed out the factors that pushed the network over the years of operation and points that deserve more attention and treatment to eliminate potential points of disruption in the operation and that can be improved and provide assistance to each of the network and associated companies hence the network itself. / A transformação da economia mundial, que trouxe a queda das barreiras e fronteiras comerciais, apresenta um cenário propício para a prosperidade das grandes corporações, enquanto, as pequenas e médias empresas ganharam dificuldades adicionais para se manter em operação. Entretanto, com o surgimento das redes de cooperação, as pequenas e médias empresas, através da sua associação em redes de cooperação, tiveram a oportunidade de se reposicionar frente a esse novo cenário. Particularmente, os supermercados de bairros, que se inserem nesse contexto, puderam adquirir condições de competividade frente às grandes cadeias de hipermercados que proliferaram neste ambiente. Com essa dissertação desenvolvida, procurou-se, através de um estudo de caso, identificar quais os fatores de competitividade alcançados por uma rede de supermercados em operação há mais 10 anos no mercado local. Foram observados e apontados os fatores que impulsionaram a rede ao longo desses anos de operação e os temas que merecem maior atenção e tratamento para eliminar possíveis pontos de ruptura na operação. Também assuntos que podem ser melhorados e trazer contribuição a cada uma das empresas associadas à rede e consequentemente à própria rede.

Mechanically Stabilized Earth (MSE) walls retain soil on steep, unstable slopes with crest loads. Over the last decade, they are becoming quite popular due to their low cost-to-benefit ratio, design flexibility, and ease of construction. Like any civil infrastructure, MSE walls need to be continuously monitored according to transportation asset management criteria during and after the construction stage to ensure that their expected serviceability measures are met and to detect design and/or construction issues, which could lead to structural failure. Current approaches for monitoring MSE walls are mostly qualitative (e.g., visual inspection or examination). Besides being time consuming, visual inspection might have inconsistencies due to human subjectivity. Other monitoring approaches are based on using total station, geotechnical field instrumentations, and/or Static Terrestrial Laser Scanning (TLS). These instruments are capable of providing highly accurate, reliable performance measures. However, the underlying data acquisition and processing strategies are time-consuming and are not scalable. This research focuses on a comprehensive strategy using a Mobile LiDAR Mapping System (MLS) for the acquisition and processing of point clouds covering the MSE wall. The strategy produces standard serviceability measures, as defined by the American Association of State Highway and Transportation Officials (AASHTO) – e.g., longitudinal and transversal angular distortions. It also delivers a set of recently developed measures (e.g., out-of-plane offsets and 3D position/orientation deviations for individual panels constituting the MSE wall). Moreover, it is also capable of handling MSE walls with smooth or textured panels with the latter being the focus of this research due to its more challenging nature. For this study, an ultra-high-accuracy wheel-based MLS has been developed to efficiently acquire reliable data conducive to the development of the standard and new serviceability measures. To illustrate the feasibility of the proposed acquisition/processing strategy, two case studies in this research have been conducted with the first one focusing on the comparative performance of static and mobile LiDAR in terms of the agreement of the derived serviceability measures. The second case study aims at illustrating the feasibility of the proposed strategy in handling large textured MSE walls. Results from both case studies confirm the potential of using MLS for efficient, economic, and reliable monitoring of MSE walls.

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