Study On Dam Break Erosion And Flood Routing Of Earth Dam

China has built a large number of dams in the whole territory.As the basis of national economic and social development,they bring lots of benefits to us.However,for the reasons that many dams exist too long and some have management problems,these dams have the potential risk of dam break for their own security problems which may bring security risks to related area.Whether it is earth dam or barrier lake,the consequences of dam break are serious.For nearly a century,dam break research has been a hot and difficult research,and many scholars have explored a lot of research on dam break problems and achieved fruitful results.But so far,the relevant theory of dam collapse is still not mature,and there is still a big gap between the prediction for dam break flood and the actual results.This paper mainly carried out the relevant research,and got the following conclusions:(1)Based on the existing numerical models of dam break,three typical models BREACH,DB-IWHR and HEC-RAS are compared by the sensitivity analysis method.The results of sensitivity analysis and calculation show that DB-IWHR model provides a software of Excel format,which is transparent,self-explanatory and friendly to practitioners.The research results can be used as a reference for the barrier lake emergency treatment.(2)Based on the Preissmann scheme and VBA language,the flood evolution calculation model is established of EXCEL format.The flood routing model and DB-IWHR form the whole process model of dam break and flood routing calculation.The reliability of the model is verified by the data of Tangjiashan Barrier Lake,which shows the results are good.(3)Based on Geospatial Information System,visualization method of flooding evolution is studied on ArcGIS.Through the processing of DEM data of Qiugou dam in Yan'an area,the results of flood calculation are obtained,and the visualization of flood routing is carried out on GIS platform.The visualization method can better reflect the evolution of flooding in the downstream area which provides a reference for flood warning.(4)Based on the cylinder scouring equipment,the soil erosion characteristics are studied.The impact flow rate and scouring rate of the soil are measured for the soil of YiGong and Xiaogangjian.The research shows that the erosion rate and flow rate of soil material in the case of low flow rate are consistent with the hyperbolic relationship,which is the same as EFA test results.According to the study of shear stress,it is found that the relationship between shear stress and erosion rate is consistent with the hyperbolic relationship,which is also similar with the experimental results of EFA.The research shows that the hyperbolic erosion model is more accurate in the calculation of the collapse.