RESEARCH ON DIFFUSION PREVENTION TECHNOLOGY WITH ENVIRONMENTAL CUTTER IN DREDGING FINE-GRAINED SEDIMENT

摘要

There has been great concern in the field of environmental dredging in regard to the efficient control of the disturbance caused by a dredger cutter during excavation that results in bed silt being partly agitated causing a diffuse pollution release into the surrounding waters.This paper discusses the background of an environmental dredging demonstration project in Wuli Lake, Wuxi, Jiangsu Province. An understanding was sought for the settlement characteristics of the fine-grained sediment, as well as performing model experiments and in-situ tests. This work was carried out in order to confirm the diffusion mechanism as well as making a contribution to the in-depth research for this technology.Laboratory experiments provided us with better knowledge of the settlement and diffusion characteristics of fine-grained sediment by way of measuring vertical settling velocity and horizontal settling distance for sediments with different grain sizes. Model tests were carried out on environmental dredger cutter models with different scales in order to study diffusion mechanisms and diffusion prevention in order to make improvements.Accumulating the experience gained through the application of those findings from laboratory experiments and model tests is helpful for construction work. In-situ studies are aimed at providing a valuable reference for diffusion prevention technology for fine-grained sediment that may be encountered in future dredging projects using an environmental dredger cutter.