RESEARCHES ON ENGINEERING REGULATION MEASURES AT NEW LIUHE SANDS AND NANSHATOU COURSE

摘要

Analysis on recently evolution processes at the division-reach of the South and North Channel of Yangtze estuary shows that, the river regime of this reach is developing towards disadvantage trend. The main characters include the continually eroding and backing off of the sand heads of the three sands (namely Central Sands, new Liuhe Sands and new Liuhe Sand-pile), and the scouring and developing of the Nanshatou course. It brings negative influences to the 10.5m depth navigation channel, the South main Channel and Changxing island tide channel. So it is necessary to take engineering measures to hold back the disadvantageous evolution. By the means of analyzing the historic evolution law and the status in quo, we came to the conclusion: it is feasible to regulate the new Liuhe Sand s and the Nanshatou course first by building dikes to protect the sand and limit the discharge through the course, even though the Baimao Sands and the Biandan Sands upstream have not been regulated yet. After the research works of numerical model and physical model, synthetically considering the regulation targets and the effects to the local river regime around the projects, the general layout of the regulation project was decided. The research work shows that the regulation project can reach the prospective regulation targets, has little disadvantageous effect to the around river regime and existing large projects, and creates good conditions for further synthetic regulations.