Numerical Simulation Of The Evolution Of The Dyke-dam Breach

With the rapid development of hydraulic engineering in this era, 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. The material of barrier dam which is created by earthquake landslide and mudslide in natural rivers is more unstable than artificial dam, so it is more likely to outburst. Dam break produces a large number of rock and water in a short time to lower reaches, so it will have a devastating disaster once occur. So the research of dam break which predict the shape and flow of water of the dam is very necessary.The existing dam breaching model were reviewed and summarized. The existing models mostly learned from the empirical relationship of hydraulics to estimate the final breach size and the breach outflow hydrograph. In this work, the physical mechanism of the dam breaching was considered to develop tailing dam breaching model. we will optimize the calculation method, parameter selection and other aspects of the dam breach based on the existing dam break model, to simulate the evolution of the dam break. The work and achievements of the paper are as follows:(1)Based on the BREACH model, introducing the non equilibrium-saturated River scour rate calculation formula to calculate the longitudinal and lateral erosion. At the same time, introducing the calculation formula of slope stability based on the principle of energy balance and limit equilibrium method to calculate the intermittent horizontal expansion. Then we can develop an improved dam breaching model.(2)Using DELPHI programming language to establish the numerical model, this model is applied in the failure of Teton dam, and the results shows that the timing, magnitude and shape of the predicted outflow hydrograph, as well as the terminal breach dimensions, are adequately simulated; accordingly the rationality and applicability of this model is validated.(3)the dam break model is applied to the Tangjiashan quake lake dam process, The calculation results and the measured data about the shape and the water flow evolution process of the Tangjiashan quake lake dam is consistent. compared the sensitivity of porosity and internal friction angle.etc.(4)Then, the model is applied to the tailings dam to simulate the development process of the tailing dam breaching, analyzes the influence on simulation results when flow parameters were selected or when mudflow parameters were selected. The calculation results show that the tailing dam simulation cannot use the dam break model parameters, and the parameters related to model and fluid in the physical process should be adjusted according to the relative characteristics of tailing flow, so it can be applied to the tailings dam break simulation better.