WATER INJECTION DREDGING IN U.S. WATERWAYS, HISTORY AND EXPECTATIONS

摘要

Water Injection Dredging (WID), where large volumes of water are injected into sediments causing them to fluidize and resulting in a near bottom density current that causes the shoaled sediment to flow to deeper areas, has been used in the US since the early 1990s. WID presents a viable and economic form of navigation channel dredging in U.S. ports and waterways under suitable conditions. The US Army Corps of Engineers (USACE) contractors have successfully demonstrated capabilities and advantages of WID on multiple navigation dredging projects. WID has proved successful on smaller scale dredging projects, typically with fine sediments, by taking advantage of WID strengths, including rapid deployment, minimal mobilization / de-mobilization and completion time, and minimal interference to navigation. This paper describes the use and progress of WID in U.S. waterways, emphasizing both operational aspects and measurements of the density current. This paper further analyzes density current in terms of the Bulk Richardson Number, R_t, as a quantitative description of WID effectiveness and efficiency. This paper will compare and contrast US WID experience to that in the Eastern Hemisphere and conclude with summary and further recommendations for WID use in Corps dredging operations.