论文部分内容阅读
溃坝洪水模拟分析中,溃口的侵蚀过程对溃口展宽和洪峰流量有直接影响,决定溃坝洪水模拟的准确性.在对圆弧滑裂面溃口展宽模型简化的基础上,将16组推移质输沙方程换算为侵蚀率,发现基于经验输沙方程的“侵蚀率—剪应力”均呈指数形式.结合唐家山堰塞湖溃决过程,对比多组经验输沙方程和指数形式的侵蚀率模型对溃坝洪水分析的影响,结果表明,采用Einstein-Brown(1950)输沙方程和指数模型中a=5,b=1.3时,模拟结果与实测资料较为相符,验证了指数模型的可行性,并通过参数率定指数模型可替代经验输沙模型.但指数模型中b值对计算结果极为敏感,甚至会导致计算不收敛,因此基于土石料最大可能冲刷率的概念提出双曲线模型,解决了这一问题,对准确模拟土石坝和堰塞坝的溃决提供一定的参考.
In the process of dam break flood simulation, the erosion process of the breach mouth has a direct impact on the breach broadening and flood peak discharge, which determines the accuracy of dam breach flood simulation.Based on simplification of the breach broadening model of the circular slip plane, The sediment transport equation is converted into the erosion rate and it is found that the “erosion rate - shear stress” based on the empirical sediment transport equation is in an exponential form. Combined with the failure process of the Tangjiashan dammed lake, we compare many sets of empirical sediment transport equations and exponential erosion The results show that the simulation results are in good agreement with the measured data when using the Einstein-Brown (1950) sediment transport equation and the index model a = 5, b = 1.3, which verifies the feasibility of the exponential model However, the b-value in the exponential model is very sensitive to the calculation results and may even lead to non-convergence of the calculation. Therefore, based on the concept of maximum possible erosion rate of soil-stone, a hyperbolic model is proposed, Solve this problem and provide some reference for accurately simulating the failure of earth-rock dam and dam.