Author(s): Yonghui Zhu; Xiaolong Guo; Yajun Xie
Linked Author(s): Yonghui Zhu
Keywords: Embankments; Headcut erosion; Breaching; Mathematical modeling
Abstract: Headcut erosion is considered as the main erosion mechanism of embankment breaching due to overflowing. However, predicting headcut erosion is an intricate problem and there is so far not a widely accepted predictive model. Based on the mechanism of headcut erosion as observed in various tests in the laboratory and in the field, the 2D mathematical model of Zhu (2006) for the headcut erosion during breaching of homogeneous embankments is improved. The model covers the shear erosion along the top of the headcut, the jet scour of the foundation and headcut undermining, and the slope mass failure. The model is capable of simulate the process and average rate of headcut erosion, with either erodible or non-erodible foundation. Laboratory experiments are conducted in a flume at the Changjiang River Scientific Research Institute in China to improve the understanding of the physics of headcut erosion. Then the mathematical model has been calibrated against the data of seven flume tests, with good agreement between the model predictions and the experimental data. Based on the model calibration results, the relationship established in Zhu (2006) between the soil erodibility coefficient (Kd) in the erosion rate formula and the embankment soil properties is improved as well. With this expression, validation of the model against the data of four other tests yields good agreement between the model predictions and the measurements.
Year: 2015