SIMULATION OF RIVER BED VARIATION BY MEANS OF FINITE ELEMENT METHOD

河床变化的有限元法模拟

• 批准号: 63550374
• 负责人: MICHIUE Masanori
• 金额: $ 1.34万
• 依托单位: TOTTORI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550374/
• 关键词: RIVER BED VARIATION; NUMERICAL SIMULATION; CONTRACTION; RIVER BEND; AGGRADATION; 混合砂河床; 洪水時の河床変動; 河床上昇; 河川狭さく部の河床変動; 流砂; 数値シミュレーション

In this study, the characteristics of river bed variation at the channel contraction during flood for uniform sand bed and mixture sand bed are investigated experimentally and numerically. From the experimental and numerically. From the experimental results it is found the tendency that the bed level approaches to the bed level on equilibrium condition of sediment discharge for flood discharge. As the results, the bed level lowers during rising stage and then phenomenon of bed aggradation during the falling stage occurs at the upstream end of the channel contraction.Numerical simulation results on the basis of one dimensional bed variation method are in good agreement with experimental data on river bed variation at the contraction. Especially, the remarkable aggradation at the end of the contraction in the experiment is well reproduced by the numerical method. And for the mixture sand bed, the critical shear stress for mean diameter is most important parameter on numerical results.The three dimensional open channel flow in the river bend is calculated by means of a numerical method of the finite differential scheme for the horizontal plane, the finite element scheme for the vertical direction. We propose the two dimensional bed variation method on the basis of the numerical results for the three dimensional flow in the river bend. The numerical simulation results are proved to coincide with the experimental data of bed variation in river bend to some extents.

本文对均匀沙床和混合沙床在洪水过程中河道收缩时的河床变化特征进行了试验和数值研究。从实验和数值上看。从试验结果可以看出，在泄洪平衡条件下，河床水位有向河床水位逼近的趋势。结果表明，在河道收缩的上游端，上升段河床水位下降，下降段河床出现淤积现象，一维河床变化法的数值模拟结果与收缩时河床变化的试验结果吻合较好。特别是用数值方法很好地再现了实验中收缩结束时的显著堆积。对于混合沙床，平均直径的临界剪应力是影响数值计算结果的最重要参数。采用平面有限差分格式、垂向有限元格式计算了弯道三维明渠水流。在对弯道三维水流进行数值模拟的基础上，提出了二维变床方法。数值模拟结果与弯道河床变化试验数据有一定程度的吻合。

项目成果

Michiue, M., Hinokidani, O. and Minamikawa, R.: "characteristics of bed variation at river contraction during flood" Proc. of the 33rd Japanese Conf. on Hydraulics, pp.283-288, 1989.

Michiue, M.、Hinokidani, O. 和 Minamikawa, R.：“洪水期间河流收缩时河床变化的特征”Proc。

道上正規: "Simulation and Countermeasure against Bed Degradation And Aggradation in River Channel" 4th Int.Symp.on River Sedimentation. 1395-1402 (1989)

Masanori Michigami：“河道河床退化和加积的模拟与对策”第 4 届 Int.Symp.on River Sedimentation 1395-1402 (1989)。

Michiue, M. and Hinokidani, O.: "The time variation of bed level at a artificial contraction during flood" Proc. 23rd Cong. IAHR, pp.347-353, 1989.

Michiue, M. 和 Hinokidani, O.：“洪水期间人工收缩时床位的时间变化”Proc。

藤田正治: "Simulation of Reservoir Sedimentation in Mountain Regions." International Workshop on Fluvial Hydraulics of Mountain Regions. B63-B75 (1989)

Masaharu Fujita：“山区水库沉积模拟”。山区河流水力学国际研讨会 B63-B75（1989 年）。

道上正規: "河川狭さく部における洪水時の河床変動特性" 第33回水埋講演会論文集. 283-288 (1989)

Masanori Michigami：“河流狭窄地区洪水期间河床波动的特征”第33届洪水讲座会议记录283-288（1989）。