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Fall 2022

White, Kendra

improve the design formulas for geobags. In riverbed sediment studies, stability is often characterized by a critical Shields parameter. To date, there is only one study that has estimated a critical Shields parameter for geobags. Critical Shields parameters rely on critical bed shear stress estimates and

correlation between the critical Shields parameter and boundary Reynolds number when applied to the critical Shields parameters. Third, the stability of a scaled geobag revetment structure, made up of uniform geobags, was evaluated for both a flat and sloped bed. Different geobag sizes and fill ratios were

tested and critical Shields parameters were estimated for each bed configuration. The critical Shields parameters ranged between 0.09 and 0.22. Geobags with lower mass and higher fill ratios tended to be more stable than geobags with higher mass and lower fill ratios. Pre-existing design formulas were

Fall 2012

Zeinali, Hossein

particles (i) predominantly smaller than 60 µm (Phillips domain), (ii) predominantly larger than 170 µm (Shields domain), (iii) intermediate in size between i and ii (intermediate domain), and (iv) of all sizes mixed together (poly-sized particles). For a bed containing predominantly Phillips-domain

particle sizes, larger particles are preferentially removed, mainly because inter-particle attraction forces (e.g., van der Waals forces) dominate in this range. The fine particles are retained in the bed. However, for a bed of predominately Shields-domain particle sizes, the smaller particles are removed

Fall 2019

Thompson, Angela

was recreated in a three dimensional numerical model, which was then used to find the shear stresses on the geobag surface. There was not enough data to confidently find a Shields parameter for geobags to use in a design capacity; however, first results imply the value to be around 0.09. These first

results also imply that the Shields parameter varies with fill percentage of the geobags.

Fall 2017

Leishman, Eric M

breaks were more common in the winter, while derailments attributed to subgrade and track geometry issues were more common in the summer. Spatially, a higher number of derailments occurred in the Cordillera, Interior Plains and Canadian Shield regions, while comparatively few occurred in the St

Fall 2020

Tang, Yangbo

this study, which could carry 0.01 to 0.50 kg/m/s sediment loading. The shields diagram and bed load transport equations were proved valid in submerged pipes. A general prediction method on equilibrium height was developed, which could be applied practically in the deposition prediction. As for erosion