Headcut migration prediction of the cohesive embankment breach
Headcut migration prediction of the cohesive embankment breach
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DOI：
10.1016/j.enggeo.2013.06.012
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发表时间：
2013-09
影响因子：
7.4
通讯作者：
Gensheng Zhao;P. Visser;P. Peeters;J. Vrijling
中科院分区：
文献类型：
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作者：
Gensheng Zhao;P. Visser;P. Peeters;J. Vrijling
切头侵蚀发生在粘性土路堤溃口的发展过程中，在溃口过程中起着重要作用。水头损失的发展是一个泥沙侵蚀和块体破坏的混合过程。基于动量平衡原理，由水下颗粒重力、颗粒间凝聚力、上举力和拖曳力共同作用，推导出粘性土的临界起动流速。通过湍流边界层流动理论，临界应力可以与这些力联系起来。用原状土试验结果对起动应力和临界流速公式进行了标定和验证。提出了一种基于弯矩平衡的方法来模拟粘性路堤漫顶溃口的水头发展和迁移。假设溃口边坡上的颗粒和质量在最小时刻被去除。通过对试验数据的验证，发现试验结果对溃口边坡的冲刷发展有较好的预测作用。该方法对预测粘性介质的破坏过程具有重要的参考价值。
Headcut erosion occurs in the development of a cohesive embankment breach and plays an important role in the breaching process. The headcut development is a mixed process of sediment erosion and mass failure. Based on momentum equilibrium, the critical incipient velocity is derived from the forces of particle weight under water, cohesive force among particles around the clay particle, uplift force, and drag force. Via the turbulent boundary layer flow theory, the critical stress can be connected with these forces. The formulae for the incipient stress and the critical velocity have been calibrated and validated with the results of undisturbed clay tests. A moment equilibrium-based method is proposed to simulate the headcut development and migration in a cohesive embankment breach due to overtopping flow. The hypothesis is given that the particle and mass are removed in the minimum moment on the breach slope. It is found that the tested results give good predictions of the headcut erosion development on the breach slope by validating laboratory data. The proposed method can be important and valuable to predict the breaching process in cohesive embankments.