截流戗堤单向进占的结构分析与应用

Structure Analysis and Application of One-way Inflow of Closure Dike

基于当前应用三维数值模型全面模拟截流戗堤单向进占过程中三维水流结构及冲刷演变过程、程度的成果较少,以库山河山区河段规划设计中近期开发的库尔干水利枢纽工程为依托,采用有限体积法和计算网格构建起水利工程截流戗堤单向进占过程的水动力学模型、河床冲淤及演变的三维数值模型,并从室内明渠截流实验中对上下游水位落差、龙口流速均值、地形变化、底床切应力分布等模拟结果的可靠性进行了验证;同时还借助所构建的数值模型,对截流戗堤单向进占方式下不同进占长度戗堤及龙口三维水流特性、戗堤冲刷态势等展开模拟分析,综合数值模拟结果和室内明渠截流实验结果,对戗堤单向进占过程中局部冲刷的原因进行了阐述。研究过程及结果可为水利工程截流实践中严重淘刷出现位置及发展趋势预测提供参考。

Based on the current application of 3D numerical model to fully simulate the 3D flow structure and scour evolution process and degree in the one-way diversion process of closure dike,there are few achievements.The finite volume method and computational grid are used to construct the hydrodynamic model of the one-way process of the closure embankment,the three-dimensional numerical model of the river bed erosion and silting and its evolution.The reliability of the simulation results,such as the water level difference between the upstream and downstream,the mean of the flow velocity at the mouth of the river,the topography change and the bottom bed shear stress distribution,is verified by the indoor open channel closure experiment.At the same time,with the help of the constructed numerical model,the author simulates and analyzes the three dimensional flow characteristics and the scour situation of the TGT with different length of the TGT under the unilateral closure mode of the TGT.The reason for the local scour during the unilateral closure of the TGT is explained by the numerical simulation results and the experimental results of the indoor open channel.The research process and results can provide reference for the occurrence position and development trend prediction of serious scour in the practice of water conservancy project.