Dredging

About: Dredging is a research topic. Over the lifetime, 3300 publications have been published within this topic receiving 28325 citations.

Using a sand wave model for optimal monitoring of navigation depth

Abstract: In the Euro Channel to Rotterdam Harbor, sand waves reduce the navigable depth to an unacceptable level. To avoid the risk of grounding, the navigation depth is monitored and sand waves that reduce the navigation depth unacceptably are dredged. After the dredging, the sand waves slowly regain their original height. To reduce the high costs of surveying and dredging, the North Sea Service of the Department of Transport, PublicWorks andWater Management, is implementing a Decision Support System to reduce the required amount of surveys and provide optimal information on the necessity to dredge. Currently, the system predicts the growth of sand waves using a linear trend. The trend is determined from observations using a Kalman-filter including geo-statistical components to incorporate spatial dependencies. This works well for sand waves that are close to their maximum height. After dredging however, the sand wave height is far from its equilibrium and the growth rate is much higher, making the linear prediction worthless. Here we show that replacing the linear trend with a landau equation improves the predictions of the regeneration. Comparison shows that the landau equation predicts the crest evolution better than the linear equation for both undisturbed sand waves and dredged sand waves, with an root mean square error that is 25% less.

Changes in an urban water resource, an example from Sydney, Australia

Abstract: This paper examines present and future resource utilization in the tidal section of the Georges River in the southern part of Sydney. Over the last 30 years, the physical characteristics of the river have changed as a result of urbanization, changed hydrologic regime and sand dredging. Urbanization has resulted in an increase in population from 190,000 in 1947 to 550,000. This has resulted in an increase in runoff, sediment input to the river and waste disposal. The change in hydrologic regime has resulted in a substantial increase in the magnitude and frequency of flooding which has increased erosion. Sand dredging has increased the channel capacity, enlarged the tidal prism and increased water turbidity. It has also resulted in extensive bank erosion in the upper part of the river and extensive deposition lower down as tailings are deposited. Although most of these changes have resulted in the deterioration of environmental quality, use of the river for recreation and as an urban amenity has increased.

Improvement of Operation and Maintenance Techniques Research Program: Demonstrations of Innovative and Conventional Dredging Equipment at Calumet Harbor, Illinois.

Abstract: : As part of a larger effort to evaluate dredging and disposal options of contaminated material at Indiana Harbor, Indiana, field demonstrations were conducted at Calumet Harbor, Illinois, to evaluate the water quality impacts of different dredging and disposal equipment. This report documents the Calumet Harbor field study and presents the results. The dredging equipment evaluations were conducted to evaluate the sediment resuspension characteristics of a cutterhead suction dredge, clamshell dredge, and Dutch-designed matchbox suction head dredge. The Calumet Harbor demonstration represents the first use of the matchbox suction head in this country. The disposal equipment demonstration included the use of a submerged diffuser designed to place material close to the bottom and reduce the exit velocities. The Calumet Harbor demonstration indicated that the clamshell dredge generated the largest suspended sediment plume affecting the entire water column. The cutterhead and matchbox dredges were successful in limiting sediment resuspension to the lower portion of the water column with the cutterhead slightly outperforming the matchbox. Improved instrumentation and increased operator experience with the matchbox suction head dredge may help in further reducing sediment resuspension. The submerged diffuser proved to be successful in limiting sediment resuspension to the lower portion of the water column and significantly reducing discharge velocities.

Municipal pipeline dredging device and municipal pipeline dredging vehicle

Abstract: The invention relates to a municipal pipeline dredging device and a municipal pipeline dredging vehicle. The municipal pipeline dredging device comprises a pipeline robot, a power line set and a pipe winder for controlling the power line set to be wound and telescopic, wherein the power line set is used for providing energy for a robot system and control cables. The municipal pipeline dredging device and the municipal pipeline dredging vehicle can adapt to various silting up conditions, sludge is scattered and milled through the dredging device and scraped to an inspection shaft, power and control cables required by the dredging device can rotate through positive 360 degrees and negative 360 degrees around a rotation driving axis through the pipe winder, the power and control cables can be telescopic in a pipe winder base sleeve, the operation radius is large, and the power and control cables can be effectively aligned with a construction station to provide good conditions for the pipeline robot.