(1. College of Civil Engineering and Architecture，Zhejiang University，Hangzhou，Zhejiang 310058，China；
2. Department of Ocean Science and Engineering，Zhejiang University，Hangzhou，Zhejiang 310058，China)
Abstract：In order to reveal the action mechanism of unsaturated debris embankment slope under rainfall action，based on the diagnoses of locale data and theory of scouring shearing stress of slope surface，generalized equation of eroding depth of slope surface is derived. Then，physical model test results are used to verify the rationality and applicability of the theoretical derivation，which reflects that the eroding depths of various points are closely related to scouring time and location on slope surface. Model test actually reproduces physical essence of embankment slopes under scouring-penetrative destruction. Combining with the model test results，mechanism of debris embankment slope caused by rainfall action is analyzed clearly. The research result is shown as follows：Firstly，intensive rainfall with long duration is the main inducing factor of instability and failure of debris embankment slope. Secondly，the scouring and infiltration penetration processes of rainwater influence and facilitate each other. Finally，the destruction development process of embankment slopes by scouring-penetration coupling can be well revealed by adopting physical model test；and the model test can provide the references for stability evaluation and taking protective measures upon similar embankment slopes.
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2011, Vol. 30 
