三峡工程泄洪坝段下游动床冲刷形态演变过程研究

Evolution of Scour Pattern on Downstream Movable-Bed in the Flood Discharge Section of Three Gorges Dam

为验证模型试验坝下动床冲刷坑形态与原型之间的差异,探讨下游冲刷演变过程,用散粒料模拟冲刷岩基,选取3组典型工况复演三峡枢纽蓄水以来泄洪坝段下游冲刷情况。研究表明不同阶段的典型试验工况与相对应条件的原型实测地形整体形态基本相似,说明冲坑形态演变与岩基地质特性有关。

This research is to verify the difference of scour pit pattern on downstream movable-bed between model test and prototype, and to investigate the evolution of scouring in the downstream. With scattered granules to simulate the scoured bedrock, we chose three typical working conditions to re-play the scour in downstream of flood discharge section of the Three Gorges dam since impoundment. We found that the simulated scour topography was consistent with that of prototype measured under typical operating conditions at different stages, which demonstrated that the evolution of scour pattern is related with the geological characteristics of bedrock. Moreover, upstream water elevation, discharge, and scour time largely affect the scour pattern in downstream of the dam.