河岸临界崩塌高度的研究

从河床冲刷下切与河岸应力的变化关系出发,分析了陡坡和垂直岸滩的崩塌挫落机制。在河床冲刷下切或者岸滩淘刷的过程中,黏性岸滩会出现纵向裂隙,促使河流岸滩崩塌。通过河岸崩塌体的稳定分析,导出折线河岸初次崩塌及二次崩塌的临界崩塌高度公式。河岸崩塌高度主要取决于河岸边界、水流因子、渗流强度、河道冲淤和岸坡土质等方面的因素。当河岸高度大于临界崩塌高度时,河岸发生崩塌。利用天然河岸崩塌高度的研究成果与模型沙崩塌高度的试验资料检验岸滩崩塌高度公式的合理性,证实了计算结果与实际基本相符。

Critical height of bank collapse

The Collapse mechanism of banks was studied based on the variation of relationship between river bed erosion and stress field in bank.Lengthwise cracks at the top of bank with cohesive soil always occur and accelerate the failure of banks.Based on the analysis on bank stability the formulas for critical height of bank collapse for banks with steep slope or vertical banks were derived.It is found that the critical height of bank collapse depends on the river boundary conditions,flow factors,bank seepage,channel erosion or deposition and soil characteristics.Bank collapse will occur if the bank is higher than the critical height.The validity of these formulas was verified by field observation data and model test results.