Test Study On Energy Dissipation And Erosion Protection For Gangquhe Stageâ…¡ Hydropower Project

As an important hydraulic structure, gate dam not only has a huge number but also is variety. Although the water level of this type of hydraulic structure is not high, energy dissipation and erosion protect issues still outstanding, because there are many problems such as erosion protection is poor in river bed and bank, and the water of downstream hasn't sufficient depth, gate is asymmetry, the river of downstream is complexity, and so on. At the same time, various projects have their unique, especially about the gate dam who has corners immediately in the lower, has little theoretical and experimental study, so it is necessary to conduct in-depth studies, for this type of gate dam project design and construction offer scientific basis. GangQuHe II hydropower stations is a typical low water level in the gate dam-type project, there is corner in downstream which impact of the flow upstream, and leading to the inadequate proliferation of flow. Because of inadequate water depth in downstream, it is difficult to form hydraulic jump, the gate hole layout is asymmetry, all these make bad flow pattern and have serious erosion in downstream. Therefore, it is necessary to consider the energy dissipation and erosion protect project feasibility, scientific and comprehensive consideration, and through the test to find out a scientific and rational energy dissipation and erosion protect project.This paper is about the GangQuHe Hydropower Station II energy dissipation and erosion protect project , through building a hydraulic model which geometric scale is 1:50, to take a model test on energy dissipation and erosion protect project of the original proposal. According to the results of the test, the energy dissipation effect of the original proposal was tested. The test was also focus on resolving the impact that the corner of the downstream exert on the discharge of upstream, from building a wall which Perpendicular to the axis of the dam to improve the flow pattern, according to the problem of the downstream corners affected the upstream water flow. On this basis, I tested different energy dissipation and erosion protect projects, and did comparative test, choosed a reasonable and economic project of energy dissipation and erosion protect according to the downstream river flow and extent of erosion and deposition. This study tested many types of slope form of apron, evaluated the steel-cage-effect by test. In the final set a separation wall on the apron, reduce the height of apron to form the vertical drop, and additional differential end sill in stilling basin, and in soil apron which is easy erosion protect with steel-cage.This test study results successfully resolved the problem of energy dissipation and erosion protect of GangQuHe II Hydropower Project, reduce the impact of corner, and reduce the erosion in the downstream, to meet the construction of energy dissipation and erosion protect requirements. At the same time, provided a reference for energy dissipation and erosion protect study of the similar projects.