中文摘要：

伸臂失败是典型河岸失败，在河岸的底部的侧面的探穴侵蚀在起一个重要作用之一。当探穴侵蚀宽度比某个价值大时，伸臂失败例如砍，倒下并且压力失败可以发生。以便理解伸臂失败的条件，伸臂失败的倒塌机制基于河岸稳定性理论和斜槽实验被学习。根据有侧面的侵蚀的河岸稳定性方程，为 shear 和简单斜坡银行的倒下的失败的批评探穴侵蚀宽度(CCEW ) 公式在这份报纸被导出。公式证明 CCEW 作为悬于的土壤厚度和土壤结合增加增加，并且在河岸表面和河岸增加的斜坡角度上作为裂缝深度减少。并且这些公式与试验性的数据被测试，它证明预言的值是对试验性的数据的好同意。纸在河伸臂失败的过程上揭示量的表情。

英文摘要：

The cantilever failure is one of the typical bank failures, in which the lateral caving erosion at the bottom of the bank plays an important role. When the caving erosion width is larger than a certain value, the cantilever failures such as shear, toppling and stress failures may occur. In order to understand the condition of the cantilever failure, the collapse mechanisms of the cantilever failures are studied based on the bank stability theory and flume experiment. According to the bank stability equation with the lateral erosion, the critical caving erosion width （CCEW） formulas for the shear and toppling failures of simple slope bank were derived in this paper. The formulas show that the CCEW increases as the overhanging soil thickness and soil cohesion increase, and decreases as the crack depth on the bank surface and the slope angle of the bank increase. And these formulas were tested with experimental data, which shows the predicted values are good agreement with experimental data. The paper reveals a quantitative expression on the process of the river cantilever failure.