Browsing by Subject "Dredging"
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Item A Dredging Knowledge-Base Expert System for Pipeline Dredges with Comparison to Field Data(2011-02-22) Wilson, Derek AlanA Pipeline Analytical Program and Dredging Knowledge{Base Expert{System (DKBES) determines a pipeline dredge's production and resulting cost and schedule. Pipeline dredge engineering presents a complex and dynamic process necessary to maintain navigable waterways. Dredge engineers use pipeline engineering and slurry transport principles to determine the production rate of a pipeline dredge system. Engineers then use cost engineering factors to determine the expense of the dredge project. Previous work in engineering incorporated an object{oriented expert{system to determine cost and scheduling of mid{rise building construction where data objects represent the fundamental elements of the construction process within the program execution. A previously developed dredge cost estimating spreadsheet program which uses hydraulic engineering and slurry transport principles determines the performance metrics of a dredge pump and pipeline system. This study focuses on combining hydraulic analysis with the functionality of an expert{system to determine the performance metrics of a dredge pump and pipeline system and its resulting schedule. Field data from the U.S. Army Corps of Engineers pipeline dredge, Goetz, and several contract daily dredge reports show how accurately the DKBES can predict pipeline dredge production. Real{time dredge instrumentation data from the Goetz compares the accuracy of the Pipeline Analytical Program to actual dredge operation. Comparison of the Pipeline Analytical Program to pipeline daily dredge reports shows how accurately the Pipeline Analytical Program can predict a dredge project's schedule over several months. Both of these comparisons determine the accuracy and validity of the Pipeline Analytical Program and DKBES as they calculate the performance metrics of the pipeline dredge project. The results of the study determined that the Pipeline Analytical Program compared closely to the Goetz eld data where only pump and pipeline hydraulics a ected the dredge production. Results from the dredge projects determined the Pipeline Analytical Program underestimated actual long{term dredge production. Study results identi ed key similarities and di erences between the DKBES and spreadsheet program in terms of cost and scheduling. The study then draws conclusions based on these ndings and o ers recommendations for further use.Item Laboratory Experiments and Hydrodynamic Modeling of a Bed Leveler Used to Level the Bottom of Ship Channels after Dredging(2011-02-22) Paul, Ephraim UdoThis study was conducted to ascertain the impacts of bed leveling, following ship channel dredging operations, and to also investigate the hydrodynamic flow field around box bed levelers. Laboratory experiments were conducted with bed levelers operating in the laboratory using video cameras for flow visualization. Computer software and numerical codes, called FANS, were used to validate the laboratory experiments. The study was split into two major parts: laboratory experiments and hydrodynamic modeling. The laboratory experiment was conducted to model how bed levelers interact with the ship channel bottom after hopper dredge dragheads (blades) made passes and created uneven trenches. These interactions were observed using both underwater and hand-held cameras. The hydrodynamic modeling was accomplished using GRIDGEN and PEGSUS commercial software for generating grid and input data files in the pre-processing phase, Finite-Analytic Navier-Stokes (FANS) software for simulation in the processing phase, and two commercial software (Fieldview and Tecplot) for plotting the images and graphs in the post-processing phase. An interesting phenomenon was observed in the laboratory experimental runs. The flow field showed reversed flow in front of the moving bed leveler and the trench parallel to the direction of the bed leveler. The flow in the parallel trench was observed to be in the same direction as the bed leveler movement, and it was expected that the flow would travel under the bed leveler. The bed leveler was towed at two specified constant speeds: 0.25 m/s (0.82 ft/s) and 0.5 m/s (1.64 ft/s) and at a water depth of 1.22 m (4.00 ft) Similarly, the images and plots of the hydrodynamic modeling obtained from FieldView and Tecplot software showed flow reversal, depicted by the negative velocities, within the vicinity of the trench, as the model bed leveler moved past and interacted with the fluid. The negative velocity had a magnitude close to 0.5 m/s (1.64 ft/s), which was the velocity used in running the laboratory experiments. The hydrodynamic simulation matched closely with the experimental observations, and thus, the laboratory observation was confirmed. The final results obtained from the numerical modeling helped to understand the hydrodynamic effects around the box bed leveler.Item Natural geological responses to anthropogenic alterations of the naples bay estuarine system(2009-05-15) Fielder, Bryan RobertThe Naples Bay Estuarine System, situated in southwest Florida, has undergone extensive modifications caused directly and indirectly by anthropogenic influences. These alterations include the substitution of mangrove-forested shorelines with concrete bulkheads, canalization of the watershed and along the bay shoreline, and navigational channel dredging. The system consists of northern Naples Bay, southern Naples Bay, and Dollar Bay, whose shorelines range from highly developed to undeveloped, respectively. This project explored the natural geological response of the system to these alterations using data from side scan sonar, sediment grab samples, and vibracores. In highly urbanized northern Naples Bay, benthic substrates consist primarily of muddy sands, with few oyster reefs. Southern Naples Bay and Dollar Bay, however, consist of coarser sediment, and are characterized by extensive mangrove shorelines and numerous oyster reefs. The impact of anthropogenic alterations has significantly shifted sediment distributions in northern Naples Bay from a coarser to a finer grained substrate. This shift has occurred to a lesser degree in southern Naples Bay, and Dollar Bay has not made this transition, due to the relative lack of anthropogenic modifications made to this part of the system.