A numerical method for simulating one‐dimensional headcut migration and overtopping breaching in cohesive and zoned embankments

Abstract

[1] An erosion and force/moments equilibrium-based numerical method is proposed to simulate one-dimensional headcut migration in cohesive embankment overtopping breaches and to simulate the one-dimensional breach process of zoned embankment dams before they fully breach through. At each time step of the simulation the depths and velocities of the breach outflow are calculated by solving the one-dimensional shallow water equations, three-dimensional slope stability is checked, and the eroded soil and instable soil block are removed. The method was tested using data from a U.S. Department of Agriculture Agricultural Research Service cohesive embankment and the Yahekou zoned fuse plug. Test results showed that the proposed method predicts well the one-dimensional headcut shape in the cohesive dam and the breach shape in the zoned embankment dam provided that the inputs are appropriately assigned. Sensitivity studies showed that the breach processes for a weakly cohesive dam under a small overtopping depth and a highly cohesive dam are controlled by erosion only. They also showed that the breach processes for a weakly cohesive dam under a relatively large overtopping depth, a noncohesive dam, and a zoned embankment dam are all controlled by erosion and force/moments equilibrium.

Numerical modelling of river embankment failure due to overtopping flow considering infiltration effects

“…However, this sophisticated numerical model also faced a problem related to disagreement of the erosion rate and used the erosion rate based on data from laboratory experiments to reproduce the phenomenon of the experiments and to focus on other topics in their study. Wang and Bowles (2007) developed an embankment breach model using one-dimensional flow and a three-dimensional slope stability model, and indicated the importance of mechanisms of local sliding during the progressive failure process. Their simulations also adjusted several soil parameters, including cohesion, internal friction angle, and erodibility of the embankment soil, to fit the experimental results.…”

Erosion Rates of Compacted Soils for Embankments

“…The mechanism of the overtopping failure needs to be adequately grasped to prevent the failure. Physical and theoretical understanding of embankment failure caused by overflow is at present under discussion 3),4), 5) . It is known that erosion on an embankment due to overflowing water develops to the failure 6) .…”

Experiments and Numerical Simulations of Dike Erosion due to a Wave Impact

“…A large study on the mechanics of embankment overflow erosion was conducted by Powledge et al [5]. Tingsanchali and Chinnarasri [17] developed a one-dimensional (1D) numerical model involving slope stability analyses, whereas a three-dimensional (3D) slope stability model was developed by Wang and Bowles [18], who also considered cohesion effects. Gotoh et al [19,20] introduced the moving-particle semi-implicit method to predict the erosion rate.…”