长期中小流量下河道整治工程迎送流关系研究

小浪底水库控制运用以后,改变了进入黄河下游河道的水沙条件及洪水过程,中小流量出现的几率大大提高。在长期中小流量过程的作用下,游荡性河道整治工程送流能力减弱,控导河势作用降低,送流不到位,工程之间发生畸弯,因此开展中小流量下河道整治工程迎送流关系研究对指导黄河下游河道整治工程布局有着重要意义。为此,我们开展了大量的实体模型单元素试验研究,初步建立了工程送流距离与流量、工程弯曲半径、靠溜长度及入流角度等整治参数的指标体系,继而又通过不同比尺的模型试验和大量的原型实测资料对送流距离公式进行了检验,相关性极好。该公式已经被黄河下游河道整治方案研究采用,直接指导了黄河下游游荡性河段河道整治工程的平面布局研究。

Experimental study on performance of flow guiding works under the long-term low flow regime

The duration of middle and small floods has become longer in wandering reach of the Lower Yellow River since the Xiaolangdi Reservoir operation. Some abnormal river bends have developed in braided reaches,because the new low flow regime has weakened the flow guiding function of the guiding works that performed well before. So,it is important to study the relation between approaching and deflecting flow by river guiding works under the long-term middle and small floods. Therefore,the sensibility of factors affecting performance of the guiding works is studied through physical model tests.A formula to reflect the guiding work performance with flow rate,bending radius of the guiding works,attaching flow distance,inflow angle and other parameters is established and verified by rich measured data.The formula has been already applied to the layout plan of the wandering reach of the Lower Yellow River.