Earth-rockfill Dam Overflow And Its Impact On The Embankments

The embankment dam has been adopted as water retaining structures in most domestic reservoir engineering, especially the small and medium ones. With the development of economy and society, the potential outburst risk of embankment dam has been taken more seriously than before. The overtopping outburst is one of the most common outburst forms of embankment dam, which is mainly due to the factors of reservoir like suffering the super-standard flood, running wrong spillway facilities operation and some other actions.It will generate huge threaten to the flood control of the downstream area if the embankment dam outburst occurred. A large number of reservoir water, whose flow may exceed the natural state flow, will rush into downstream rivers in a short time. If the level of flood is higher than the height of the embankment, people on both sides of the river will be suffered huge damage of their properties. Because it is rarely to consider the large flood caused by dam breaking in the dike design during the normal circumstances, it is necessary to simulate the process of the flood caused by embankment dam outburst and analysis the impact on the downstream embankment, providing guidance and strategy for the flood control planning and flood emergency plan formulating. This paper mainly studied the flow calculation method of embankment dam overtopping outburst and the effects on downstream river embankments. The main works are as followings:First, based on the previous studies about embankment dam overtopping outburst, this paper put proposed a numerical method for calculating embankment dam overtopping outburst flow and compiled computer programs about the two different outburst flow calculation models. The calculation methods and procedures proposed in the paper have been verified by the simulations of one practical case in two different models.Second, by using the software HEC-RES which is adopted in water level calculating, this paper made the evolution analysis of embankment dam outburst flood in several typical river sections, and the main part of the process is to analyze the security situation of downstream embankment dam outburst in the condition of the embankment dam outburst occurred in the upstream.Third, combining with the safety analysis method, this paper discussed the control measures for risk of embankment dam-river system.This paper took the embankment dam outburst and the river as a whole comprehensive system and analyzed the embankment dam outburst, flood evolution and the risk of the dam protection suffered from the flood systemically. It will be not only helpful for the safety assessment of embankment dam and dam project, but also to the reasonable emergency management of flood control.