摘要
本文系统比较了三峡工程与葛洲坝工程的具体条件，结合泥沙实体模型和数学模型的研究成果，提出了三峡引航道冲沙流量的合理规模。三峡工程可以用较葛洲坝工程规模小的“小流量冲沙”措施实现“动水冲沙”。通常条件下，将引航道冲沙设施的规模控制在４０００ｍ３／ｓ的范围以内，就可以达到很好的冲沙效果；如果冲沙时进一步考虑小幅度降低水库水位，则尚可以进一步降低冲沙流量或增加冲沙效果。降低水位冲沙系非结构措施，可以作为今后运用中的安全余地。本文建议，三峡工程采用４０００ｍ３／ｓ的冲沙流量规模。
This article presents the results of study on the discharge needed to scour the lock approaches of TGP. It is based on an analysis of the experience obtained with flushing sediment deposition in the lock approaches of the nearby project Gezhouba as well as on the results of mathematical and physic modeling. Gezhouba project is a run of the river plant and is about 38km downstream of TGP. Every year large amount of water is wasted over the dam. Its lock approaches have thus been successfully maintained by flushing with surplus water at a maximum discharge 8000 m 3/s.Since TGP features a high dam with a large reservoir and a powerhouse of large installed capacity, water is valuable. It is thus desirable to save on the amount of water used in flushing. Fortunately, the upper lock approach channel in the case of TGP is considerably shallower than that of Gezhouba. Consequently, a discharge of about 4000 m 3/s only would be sufficient to flush out the sediment deposited in the upper approach channel of TGP. The sediment so flushed would be partially accumulated in the lower approach. But as the lower approach channel during the flood season has a depth of flow of about 12m, the deposition so resulted would not hamper navigation. At the end of the flood season, the tailwater of the TGP subsides and may even be further lowered by regulation of Gezhouba immediately downstream to give the lower approach channel a small enough depth of flow. Whatever residual deposition in the lower approach channel may then be easily sluiced out by flow. It is also shown that by temporarily drawing down the reservoir by 2m, the flushing discharge may be further reduced from 4000 to only 2500m 3/s.
出处
《泥沙研究》
CSCD
北大核心
1999年第3期1-7,共7页
Journal of Sediment Research
关键词
三峡工程
引航道
泥沙淤积
动水冲沙
小流量
Three Gorges Project(TGP), lock approach, sediment, flushing, scouring
