This Thesis describes a method for determining and analysing the deformations in peat caused by a driven rigid wheel. Markers were placed in the peat sample and radiographs were taken as the wheel travelled over the surface of the peat. An analysis of the data revealed that a unique relationship existed between the positions of the markers and the positions of the wheel. The paths of the principal stress trajectories were determined by a graphical method; from the principal stress trajectories, it was possible to find the surfaces of maximum shear. The purpose of determining these surfaces is to allow the equilibrium of the soil mass to be investigated by the present theories in soil mechanics; it is to draw an analogy to the analysis of slope stability problems. / Thesis / Master of Engineering (ME)

The overall goal of this thesis is to present a comprehensive understanding of the Nottawasaga River system. In the first chapter, we will examine how landscape features (geomorphology and land cover) drive spatial variation in nutrient and sediment loading from 11 sub-watersheds to the Nottawasaga River. The second chapter will relate how tributary loading and other in-stream processes (riffles, substrate, dissolved oxygen) contribute to the longitudinal variation in water quality along with middle and lower reaches of the Nottawasaga River. Finally, in the last chapter we use 13 water quality variables to develop a Stream Water Quality Index (SWQI) to identify critical areas in the NRW that are most at risk. This thesis will provide environmental agencies with useful information to help implement management strategies to improve the health of riverine systems at a watershed scale. / Eutrophication from agricultural runoff is a global problem, often resulting in formation of anoxic zones in receiving water bodies. The Nottawasaga River Watershed (2,900 km2) is dominated by agricultural land-use, and is a major source of nutrients and sediment to Nottawasaga Bay, Georgian Bay (Lake Huron). The primary objective of our study was to develop a holistic understanding of the different sources and processes that influence spatial variation of water quality across the Nottawasaga River (121 km). In our first chapter, we use landscape features to develop 6 models that predict daily base flow loading rates of total phosphorus (TP) and total suspended solids (TSS) from 11 sub-watersheds. We found that drainage area and % pasture land were the most significant predictive variables driving spatial variability in TP and TSS loading. We also found a significant positive relationship between TP and % wetland, suggesting that the Minesing Wetlands (largest inland wetland in southern Ontario) are a source of nutrients to the river. In our second chapter, we evaluate how tributary inputs and in-stream processes contribute to the longitudinal variation in water quality along the Nottawasaga River. We found that tributary concentration and discharge significantly predict downstream turbidity (TURB), but do not predict downstream TP. We also found that riffles improve water clarity, and that silt and clay substrate is significantly associated with high TURB. In our third chapter, we develop a Stream Water Quality Index (SWQI) using 13 variables collected at 15 stations along the Nottawasaga River. To predict SWQI scores for any site, we have provided 9 equations that use various combinations of available variables. Understanding landscape variables, as well as tributary and in-stream processes that influence water quality will enhance the development of restoration initiatives to improve ecosystem health in lotic systems at a watershed scale. / Thesis / Master of Science (MSc) / Eutrophication from agricultural runoff is a global problem, often resulting in formation of anoxic zones. The Nottawasaga River Watershed is dominated by agricultural land-use, and is a major source of nutrients and sediment to Georgian Bay, Lake Huron. The objective of our study was to develop a holistic understanding of sources and processes that influence spatial variation of water quality across the Nottawasaga River. We found that landscape features (drainage area, pasture, wetland), tributary inputs, and in-stream processes (riffles, substrate) significantly influence water quality. Our results will enhance restoration initiatives to improve health of riverine systems at a watershed scale.

<p> This thesis describes the construction and testing of small-scale shear wall buildings with rigidly connected floor slabs, but without wall openings. A micro-concrete material was used in the casting of both the basic small-scale shear wall buildings and the floor slabs. The vertically cantilevered buildings were tested by applying a transverse static load at the top of the buildings.</p> <p> The behaviour of buildings with only floor slabs was compared with that of buildings containing only wall openings. The results of static loading of the buildings were compared with those results predicted analytically using Vlasov's thin-walled elastic beam theory.</p> / Thesis / Master of Engineering (MEngr)

The tibia is a frequent site of injury in frontal automotive collisions. The bulk of experimental cadaveric studies on injury tolerance assume load is applied in line with the leg’s long axis, leaving non-standard postures largely uninvestigated. The purpose of this work was to study the effects of non-standard postures on the tibia’s injury tolerance. A pneumatic system was designed to facilitate impact testing. This system allows the user to fire a projectile of variable mass towards a specimen at a range of velocities by varying the supplied air pressure. Impact tests were performed using pairs of isolated cadaveric tibias. Within each pair of specimens, two postures were compared by varying the angle of the bone’s long axis relative to the direction of impact, representing knee extension and corresponding plantarflexion. It was found that the specimens held further from the axial posture sustained injury at lower forces. Two commonly-used Anthropomorphic Test Device legforms were impacted in these non-standard postures. New load limits were proposed for the use of these devices in off-axis impact testing. In order to compare directly with the loads measured by the legforms, it was necessary to measure forces and moments internal to the bone’s long axis. A non-invasive load estimation method was developed and tested using strain measured from the surface of four specimens. The method performed poorly under impact conditions, but may be refined in the future. Quantifying the effect of posture on injury risk in the tibia allows for the refinement of existing injury criteria. Ultimately, this can be used to enhance the design of protective devices to reduce the incidence of tibia fractures in automotive collisions. / Thesis / Master of Applied Science (MASc) / Fractures of the tibia (the shin bone) are common in automotive collisions, and often lead to long-term impairment. Experimental studies on these kinds of injuries are usually performed with the lower leg aligned with the direction of impact, which does not reflect the range of postures an occupant may assume during a crash. Cadaveric tibias were subjected to impact loading in two different postures. It was found that the specimens held further from an axial posture sustained fractures at lower forces. Two commonly-used crash test dummy legs were also impacted in these non-standard postures to test their performance. Suggestions were made for new load limits to be used with these devices in non-standard postures. The finding that leg posture has an effect on injury risk in the tibia can be used in the future to design and evaluate better protective devices and ultimately reduce the incidence of these injuries.

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