The purpose of this study was to investigate the highest bottom shear stress, induced by wind in an area of Hamilton Harbour, Ontario, Canada known as Randle Reef. The study was conducted in support of a component of a contaminated sediment remediation plan utilizing a thin layer of sand to manage contaminated sediments. Toward this end, four acoustic Doppler current profilers (ADCPs) were deployed at two locations in the study region to measure velocity profiles for the purpose of indirectly measuring bottom shear stress (BSS) and model verification. There is no easy way to directly measure BSS in the field. As a result, the use of the logarithmic-profile method from the ADCP measured high resolution velocity profiles in the bottom layer was explored. This approach, according to our best knowledge, has not been published for a wind driven flow in a small open water body. To use the indirectly measured BSS to estimate the highest BSS in the study area, a three-dimensional hydrodynamic model was adopted to provide the spatial and temporal information of the bottom flow. The results showed that the modeled and measured flow velocity components agreed reasonably well at most of the water depths with the correlation coefficients being greater than 0.6. However, agreements between the modeled and measured bottom flow speeds were worse than expected due to the error contributions from both the modeled velocity components. Therefore, the modeled flow speed required rescaling based on ADCP velocity measurements before it could be deemed reliable. This is especially important in estimation of the BSS with a quadratic formula because the calculated BSS is proportional to the square of the speed.Résumé : La présente étude avait pour but d'examiner la contrainte de cisaillement de fond la plus élevée induite par les vents dans un secteur du port d'Hamilton, Ontario, Canada, connu sous le nom du récif Randle. L'étude a été réalisée dans le cadre d'un plan de remise en état de sédiments contaminés utilisant une couche mince de sable pour gérer les sédiments contaminés. Dans ce but, quatre profileur de courant à effet Doppler (ADCP) ont été placés en deux endroits de la région à l'étude dans le but de mesurer les profils de vitesse afin de mesurer indirectement la contrainte de cisaillement de fond (BSS) et vérifier le modèle. Il n'existe aucune méthode facile de mesurer directement la BBS sur le terrain. La méthode du profil logarithmique de l'ADCP pour mesurer des profils de vitesse à haute résolution dans la couche de fond a été examinée. Cette approche, au meilleur de notre connaissance, n'a jamais été publiée pour un courant dû au vent dans un petit plan d'eau libre. Un modèle hydrodynamique tridimensionnel a été adopté pour fournir de l'information spatiale et temporelle sur l'écoulement de fond afin d'utiliser la BSS mesurée indirectement pour évaluer la plus haute BSS dans la région à l'étude. Les résultats montrent que les composantes de vitesse de débit modélisée et mesurée concordent assez bien à la plupart des profo...

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A correct understanding of passive force-deflection response is important for lateral load evaluations of bridges during extreme events such as earthquakes and from thermal expansion and contraction of the superstructure. In these cases, the ultimate passive force is highly sensitive to the interface friction between the abutment wall and the adjacent geomaterials. These geomaterials may simply consist of compacted sand or gravel; however, for geosynthetic reinforced soil (GRS) backfill a geosynthetic fabric may be placed between the abutment wall and soil which can reduce the interface friction. In still other cases, a zone of compressible material such as geofoam may be used as a barrier between the soil and abutment to reduce lateral earth pressures. To evaluate the effect of the interface friction on passive force-deflection curves, large-scale testing was performed with a test abutment that was 3.35 m wide and 1.68 m high. Backfill materials consisted of sand, gravel, GRS backfill, and a geofoam inclusion between a sand backfill and the abutment. As a result of lower interface friction, the GRS backfills only developed 80% of the force developed by the unreinforced gravel. The geofoam inclusion decreased the passive force by about 70% as a result of reduced interface friction.