The influence of yielding foundations on the mechanical behaviour of reinforced soil walls including wall deformations and loads (strains) in the reinforcement layers is very complex. Based on a review of the literature, there is a need to quantify and isolate the influence of foundation boundary type and magnitude of foundation stiffness on deformations and reinforcement loads in geosynthetic reinforced soil walls. This thesis presents the results of a series of 1/6-scale reinforced soil wall model tests that were carried out to examine the influence of horizontal and vertical toe compliance and vertical foundation compressibility on wall behaviour. The heavily instrumented walls were constructed in a strongbox that was 1.2 m high by 1.6 m wide and retained soil to a distance of 2.3 m behind the facing. The models were uniformly surcharged in stages following construction. The experimental program consisted of three groups of tests. Group 1 tests involved five walls. One wall was constructed with a very stiff horizontal restraint, and three walls were constructed with different horizontal toe stiffness using combinations of coiled springs. The remaining wall in this series was constructed without any horizontal toe restraint. Group 2 was comprised of three walls. One wall was a control wall with a rigid toe. The other two walls were constructed with different vertical toe stiffness support using different combinations of rubber blocks. Group 3 included a control wall with a rigid foundation and a companion wall constructed with a compressible foam and rubber layers below the backfill soil and the wall facing. The results demonstrate that the quantitative behaviour of the models was affected by the type and magnitude of foundation stiffness. For example, as horizontal toe stiffness increased a greater portion of the total horizontal earth load against the wall facing was carried by the toe. The data showed that the shape of facing lateral deformation profiles changed from rotation about the toe for the case of a very stiff horizontal toe to a more uniform profile for the unrestrained toe case. For the case of a rigid vertical footing support below the facing, vertical toe loads were greater than those computed from facing self-weight alone due to down-drag forces developed at the facing–reinforcement connections as the wall facing moved outward. As vertical toe support stiffness decreased with respect to foundation compressibility below the soil backfill, the magnitude of soil down-drag forces diminished resulting in a decrease in vertical toe load. / Thesis (Master, Civil Engineering) -- Queen's University, 2007-10-27 12:15:56.027

The use of natural light is very beneficial in office buildings because energy consumption can be reduced, and working conditions can be enhanced, which positively affect workers' health and productivity. However, bringing natural light into deep plan office buildings is not possible with simple windows or skylights, and light transport systems are necessary to bring natural light into the deep cores of buildings. Light transport systems usually need sun-tracking devices to collect natural light that are complicated, expensive and require continual maintenance. Mirrored light pipes coupled with laser cut panels (LCP) are a passive and simpler daylight transport solution and are the focus of this PhD research. The primary aim has been to improve the technology and achieve the most efficient passive solution possible through the interactive use of theoretical modelling, experimental measurements and case studies. Applications of this technology were investigated in two case studies: 1) as horizontal light pipes for daylight illumination of a high rise building proposal in the tropics; and 2) as vertical light pipes for daylight illumination of a middle-rise deep plan building proposal in a subtropical environment. In both cases, quantitative system performance under best (clear sunny sky) and worst (overcast) case scenarios was undertaken via scale model testing and mathematical modelling. The major conclusion for both case studies was that mirrored light pipe technologies, when coupled with LCP, were effective in introducing sufficient ambient light levels inside buildings and over distances > 20 m from the façade or roof. Average lux levels achieved in the space were 150 to 350 lux for the horizontal light pipes and 50 to 300 lux for vertical light pipes. However, as a passive solution, this technology has two major limitations: 1) the dependence on sun azimuth and elevation angles, which result in variations in illuminance levels during the day and the year; and potentially 2) pipe size, as pipes with a large diameter (e.g. 2 m in diameter for 20 m long pipes) are required for optimal performance, such that the large pipes may limit integration in building design. Two other solutions were assessed to circumvent these limitations to the mirrored light pipe technology: 1) a passive collector that concentrate natural light by using a fluorescent panel to reduce the size of the pipe, and 2) an active collector comprising a LCP rotating 360 degrees in a 24 hour cycle to reduce system dependence on sun azimuth and elevation angles. The low light-to-light efficiency of the fluorescent panels made them inappropriate for collecting sufficient amounts of daylight necessary for daylighting of large buildings. In contrast, the rotating LCP is a very simple active system that by rotating constantly at 15 degrees per hour, reduces the deviation angle between the panel orientation and sun azimuth angle, and significantly increased the system performance. The performance was generally better (e.g. 2.5 times better for light collection under low sun elevation angles) than the passive light pipe system with fixed LCP. However, active systems raise other issues in terms of cost-benefit in constructing, operating and maintaining such systems. Passive mirrored light pipes coupled with LCPs or simple active systems with rotating LCPs have great potential as daylight solutions for deep plan buildings as they can contribute to lowering overall energy consumption, improve workplace health and become an architectural design element. Research is still required on the implementation of the technology into buildings, but the growing trend towards 'green buildings', sustainable design and government regulations or building codes will require more daylighting use in buildings, and will motivate designers to increasingly consider and incorporate such daylighting strategies into future building designs.

Dams are vital infrastructure for society as they provide various services (e.g., flood prevention, storage of byproducts from mining operations, water storage for irrigation and hydropower generation) by the impoundment of liquids. However, the storage of considerable volumes of liquids introduces a risk of uncontrolled discharge, due to dam failure, which could result in catastrophic outcomes. Consequently, the safety must be ensured throughout a dam’s service life and thus regular assessments are required. For concrete dams, the current practices of stability assessment methods found in guidelines and regulatory rules require idealizations. This need for idealization is a weakness of current assessment methods as elucidated by the appended scientific articles. The essence of the results of the appended articles demonstrates that certain parameters and features of a dam, which are commonly neglected in current dam assessment, significantly influences the load capacity of a dam. Therefore, this study primarily deals with alternative assessment methods that can be used for dams. Therefore, as an outcome of an extensive literature review on probabilistic analysis and scale model testing, summarized in the chapters of the thesis, a framework for concrete dam assessment is proposed. Even though the methods can be individually employed to assess the stability and safety of a dam, an approach that integrates the strengths of each method is currently not available. The proposed framework is novel and combines scale model testing, finite element analysis, probabilistic analysis and is intended to resolve issues identified with current assessment methods. The framework integrates the strengths of each method provides a robust assessment strategy where cross-validation of the failure mode and capacity is achieved by utilizing both finite element analysis and scale model testing. Furthermore, in contrast to current dam assessment methods, it allows for large geometrical variations in the rock-concrete interface to be included in the analysis, which contributes significantly to the capacity of a concrete dam as elucidated by the appended articles. The work in this thesis presents the theoretical foundation of the framework. It is intended to be applied in a future case study to evaluate its performance on an existing buttress dam.

Wind propulsion is a traditional way to propel ships over the oceans. In the recent development towards more sustainable shipping, sailing is considered in the industry again with high momentum. For a modern merchant ship, the aerodynamic forces generated on the particular rigging are unusual. Tailored research and experiments are required to understand their influence on the ship’s sailing behaviour. This work concerns the aerodynamic interactions on a model-sized car carrier with four 360° rotatable, symmetric, rigid wings aligned along the centreline on deck. Differential pressures on the wings are measured to capture the generated normal forces. In a comprehensive post-processing, data recorded in systematic experiments at two apparent wind angles were evaluated. A comparison for the different wing positions on board the model shows stronger interactions in upwind sailing conditions than when reaching. The two-dimensional data prove a significant influence of the hull in the normal force profiles over the wing span. The results of this work indicate that the aerodynamic conditions while sailing have to be attentively considered for efficient wing trimming. / Under en lång tid användes främst vindkraft för framdrivningen av fartyg. Det är först på senare år att seglingskonceptet har fått ett nytt uppsving inom marinindustrin med tanke på dess hållbarhet. För fraktfartyg är de aerodynamiska krafterna vid segling ovanliga. Därför behövs särskild forskning och experimentella metoder för att förstå hur de påverkar fartygens seglingsbeteende. I detta arbete undersöks aerodynamiska interaktioner på en modell av ett biltransportfartyg med fyra symmetriska, 360° roterbara vingsegel på däck längs midskeppslinjen. I systematiska experiment på två kurser mot vinden mättes differenstryck över vingprofilen för att undersöka de genererade normalkrafterna. En jämförelse av data från de fyra olika vingpositionerna och båda kurserna mot vinden visar att de aerodynamiska interaktionerna är starkare på kryss än vid halvvind. De upmätta profilerna av tvådimensionella normalkraftkoefficienter över vingspannet visar på betydande aerodynamiska interaktioner med fartygets skrov. Resultaten av detta arbete visar hur viktigt det är med en grundlig undersökning av strömningsförhållandena för en effektiv segeltrim.