1引言在水利工程溢洪道设计中，其进口常设置有带胸墙的泄流孔口，这种布置型式可在库水位较低时开始池流，有利于提高水库汛限水位，降低坝高，同时利用胸墙挡水，泄洪孔口尺寸较小，闸门尺寸也较小，可节省工程投资。当库水位超过胸墙底线一定高度时（即e／H0≤0．75，见图1 1 Introduction In the spillway design of water conservancy project, the discharge port is always provided with a chest wall. This type of arrangement can start pool flow when the reservoir water level is low, which is beneficial to increase the flood control water level of the reservoir and reduce the height of the dam. At the same time The use of chest wall water, flood discharge orifice size smaller gate size is also smaller, which can save the project investment. When the water level exceeds the chest wall at the bottom of a certain height (ie e / H0 ≤ 0.75, see Figure 1