明渠流条件下桥墩（群）阻水效应实验与数值研究

发布时间：2018-03-07 01:20

本文选题：明渠水流　切入点：阻水效应　出处：《上海交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着工业化、城镇化进程不断加快,交通线路设计规划不能只依赖陆地空间,跨水域交通作为目前解决该问题较为有效的手段已成为社会基础建设的重要组成部分。桥梁等涉水基础建设势必会引起桥梁附近水域河床阻力、水流流态、流速分布、过流能力和岸坡稳定等发生变化。因此,如何计算涉河桥梁下部基础引起的水位雍高,如何评估桥梁建造后下部基础对河道上下游河势的影响范围及影响程度,如何对桥梁阻水能力进行量化论证并给出适用的概化指标,是水利工程师致力解决的一个重要问题。在较为全面且系统地回顾和总结了关于桥墩雍水这一主题的理论发展体系及国内外研究现状之后,本论文将桥墩建造后上下游水面曲线变化规律作为研究对象,结合理论推导、水工模型实验和数值仿真计算手段,对桥墩周围水位相对变化幅值进行了一系列深入研究,提出了一个无量纲归一化形式的桥墩阻水效应经验表达式,具体研究内容如下:1.利用水工模型实验手段分析桥墩放置前后水面曲线变化,基于实验数据,从受力平衡及能量守恒两个角度分析推导桥墩全局阻水效应系数理论计算表达式,并通过无量纲、归一化等数学手段提出一个仅与流态Fr有关的,用于计算桥墩阻水效应的双参数经验简化公式;2.利用数值仿真计算手段模拟不同Fr数的流态工况背景下,桥墩周围特定计算域内水位变化特征,分析并确定桥墩阻水效应分布规律及影响范围,依据仿真计算结果率定桥墩阻水效应经验公式中的双参数,给出双参数桥墩阻水效应计算公式的修正形式及双参数与流态Fr数的函数表达式;3.基于上述研究途径及研究工作实施思路,利用水工模型实验手段探讨不同阻水效应影响因子对桥墩群周围雍水幅值的影响程度及变化规律,总结描述相关影响因子与雍水幅值之间的定性关系。本论文所取得的具有重要理论和实际意义的研究成果,能够为大尺度河流水动力模拟中桥梁墩柱的概化提供一定参考依据。
[Abstract]:With industrialization and the acceleration of urbanization, the design and planning of transportation routes cannot rely solely on land space. As an effective means to solve this problem, cross-water transportation has become an important part of social infrastructure construction. The river bed resistance, water flow pattern and velocity distribution are bound to be caused by the bridge and other water-wading infrastructure construction near the bridge. Therefore, how to calculate the water level uvula caused by the lower foundation of the bridge, and how to evaluate the influence range and degree of the lower foundation on the upper and lower river regime after the bridge is built, and how to calculate the water level uvula caused by the bottom foundation of the bridge. How to quantitatively demonstrate the water resistance capacity of bridges and give the applicable generalization index, It is an important problem to be solved by water conservancy engineers. After a comprehensive and systematic review and summary of the theoretical development system on the theme of the uvula of bridge piers and the current research situation at home and abroad, In this paper, the variation law of water surface curve after pier construction is taken as the research object, combining with theoretical derivation, hydraulic model experiment and numerical simulation method, a series of deep research on the relative variation amplitude of water level around pier is carried out. In this paper, an empirical expression of water resistance effect of pier in dimensionless normalized form is presented. The specific research contents are as follows: 1. The changes of water surface curve before and after pier placement are analyzed by hydraulic model experiment, based on experimental data. This paper analyses and deduces the theoretical expression of the global water blocking effect coefficient of bridge pier from two angles of force balance and energy conservation, and puts forward a formula related only to flow state Fr by mathematical means such as infinitesimal, normalization, etc. The two-parameter empirical simplified formula used to calculate the water resistance effect of bridge piers 2.Using the numerical simulation method to simulate the variation characteristics of water level around the pier in the specific computational domain under the background of different Fr numbers. Based on the analysis and determination of the distribution law and the influence range of the water resistance effect of the pier, the double parameters of the empirical formula for the water resistance effect of the pier are determined according to the result of the simulation calculation. The modified form of the formula for calculating the water resistance effect of the double-parameter bridge pier and the functional expression of the two-parameter and the Fr number of the flow state are given. 3. Based on the above research approach and the practical thinking of the research work, By means of hydraulic model experiment, the influence degree and variation law of the influence factors of different water blocking effect on the amplitude of Yongshui around the pier group are discussed. The qualitative relationship between the related influence factors and the amplitude of the uvula is summarized and described. The important theoretical and practical research results obtained in this paper can provide a certain reference for the generalization of bridge pier columns in large-scale hydrodynamic simulation of rivers.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.3

【相似文献】