流滑型崩岸河岸侧蚀模式初探

Preliminary study on the analytical model for slide collapse of riverbanks

流滑型崩岸是冲积河流河岸常见的一种崩塌形式,其发展速度快、破坏力强;该类崩岸主要取决于水流的直接冲刷,河岸崩退过程中水面与岸顶高差较小。依据此类崩岸的特征,基于水流冲刷分析,在基础层面上初步探讨并建立了流滑型崩岸的河岸侧蚀模式。结合水槽试验与土工离心模拟试验,对该模式进行了分析研究,初步率定了模式中的河岸侧蚀系数,计算值与实测值吻合较好。该模式参数少、应用方便,可为流滑型崩岸中河岸侧蚀的估算及河道横向变形数值模拟提供参考依据。

The slide collapse of riverbanks with fast-developing, large rates of bank erosion, and strong destructive powers is a common type of riverbank collapses in alluvial rivers. This type of failure is mainly caused by the direct impact of flow water, as well as resulting from the fact that water level is too close to the top of riverbanks in the course of collapse. An analytical model for the slide collapse of riverbanks is presented based on the analysis of scou- ring effects on the riverbanks. The model structures and parameters are evaluated using the flume experiments and centrifugal tests. The erosion coefficient of river bank is calibrated using the experimental data. The model result is in good agreement with the experiments. The analytical model contains only a few parameters and is easy to apply . The model result can be used as a reference for the prediction of riverbank erosion and channel migration.