Study on Treatment Technique for Tu'naozi Shoal in Three Gorges Reservoir Area

According to the natural condition,Tu' naozi shoal don't have obvious influence on the boat's sailing,for it only silts in the floodwater;when the water is low,the shoal is washed out.However,when Three Gorges Project runs the scheme of 139m water level,the problem of the accumulative deposition becomes more and more severe,for the sediment situates the end of the reservoir and the sediment deposited at high-water period can't be washed out completely.Firstly,the dangerous condition of the shoal and the process of the treatment during last three years are introduced.Secondly,through the analysis of shoal evolvement rules in the cases of natural condition and the sluice of Three Gorges Project as well as the shoal's mechanism of baffling sailing,the techniques about engineering maintenance measurement,construction and the choice of construction time are explored.The conclusion offers some reference to the treatment of the similar shoals at the end of the reservoir and the shoals at the 175m water level.