长洲枢纽下游人工节埂防冲措施研究

Research on anti-scour method by using artificial stone banks at the downstream of Changzhou Reservoir

针对长洲水利枢纽建成后,下游河床冲刷引起的枯水位下降,可能导致枯水期船闸下闸首门槛水深不足的问题,应用二维悬移质泥沙数学模型对枢纽建成后下游河床的冲刷下切及枯水期水位降落情况进行预测,结合当地的河床形态及地质条件,提出在坝下河道布置一系列的护底工程,形成不连续的人工控制节埂的防冲措施,以达到抑制河床冲刷、抬高近坝段枯水水位的目的。研究表明:通过在长洲枢纽下游河道合理布置人工节埂,可以有效地抑制下游河床冲刷,减小坝下枯水水位的下降值。

After the completion of Changzhou Reservoir, the low water level declines because of bed erosion at the lower reach of the reservoir.h may cause the deficiency of water depth.In order to solve this problem, a 2-D suspended sediment mathematical model was applied to predict the process of riverbed longitudinal erosion and fall of water level at the downstream of Changzhou Reservoir.Based on the local bed configuration and geological conditions, a regulation method of arranging a series of bottom protection in the reach below dam was proposed. These bottom protection formed discontinuous artificial stone banks to prevent erosion and raise the low water level at the downstream of the project.A reasonable arrangement scheme of artificial stone banks was discussed. The calculation results show that the river bed erosion and fall of water level near the dam can be controlled obviously after the regulation.