水位变化速率对河道崩岸的影响

Influence of Water Level Change Rate on Riverbank Collapse

针对天然河道崩岸现象,采用概化模型试验和数值计算相结合的方法,初步分析了不同水位变化速率对河道崩岸的影响。研究结果表明:水位变化对崩岸有明显影响,尤其在水位降落阶段,水位降落速率越大,崩岸越明显。岸坡稳定性计算结果显示涨水时稳定系数随水位上升而增大,至高水位后稳定系数先减小后保持稳定,水位降落阶段稳定系数减小,且与降落速率密切相关。研究成果可为分析不同水位变化速率下岸坡稳定性的演化特征并采取相应的河道整治措施提供理论依据。

The influence of water level change rate on riverbank collapse was examined via generalized model test and numerical simulation.Results demonstrated that water level fluctuation had significant impact on bank collapse.Particularly,in the stage of water level drawdown,the larger the dropping rate,the more evident the bank collapse.Stability calculation of bank slope revealed that the factor of stability augmented in the stage of water level rising,but once the water level reached a high value,the factor of stability declined at first and then maintained stable;in the stage of water level drawdown,the factor of stability reduced and was closely related to the dropping rate.The research finding offers theoretical basis for analyzing the evolution of bank slope stability under varying water level fluctuation rate and also for taking corresponding treatment measures.