桥墩影响下河流冰塞增厚分析研究

发布时间：2018-03-25 06:11

本文选题：冰塞　切入点：试验研究　出处：《合肥工业大学》2017年硕士论文

【摘要】：冰塞是寒冷地区江河中比较容易出现的冰情现象,冰塞的出现使河道过流断面减小,导致不同程度的堵塞,河道过流能力变弱,致使上游水位显著壅高,沿河两岸常因此发生凌洪灾害。桥墩的存在改变了河道边界条件,影响了桥墩附近河道的水流结构,冰塞的受力状态发生改变,导致河道中冰塞形成变得更加容易,冰塞的演变也更为复杂。因此,研究桥墩影响下冰塞的演变规律对预防冰凌灾害具有重要意义。国内外河流冰塞研究方法大致分为数值模拟、原型观测以及试验研究三个方面。在分析国内外研究现状的基础上,通过对直道和弯道冰塞演变的试验研究,发现和分析了试验中的规律。冰塞演变分为两个阶段:初始堆积阶段和后期增厚阶段。直道试验冰塞初始堆积阶段有两种演变形式,两种形式临界受初始冰流量和初始流速影响,而不会受桥墩和墩宽的影响;初始堆积阶段冰塞的堆积速度、水位增值和冰厚分布都会随着冰流量、水流初始流速以及水流明流水深的改变而改变,后期增厚阶段冰塞的水位增值和冰厚也会随着水流初始流速和明流水深的改变而改变,桥墩的出现对冰塞堆积速度影响较为明显,但对水位和冰厚影响较弱。
[Abstract]:Ice slug is a kind of ice phenomenon which is easy to appear in rivers in cold area. The appearance of ice slug reduces the cross section of river channel, leads to different degrees of blockage, weakens the capacity of river flow, and makes the upstream water level rise significantly. The existence of piers changes the river boundary conditions, affects the flow structure of the river near the pier, and changes the stress state of the ice slug, which makes it easier to form the ice slug in the river. The evolution of ice plug is also more complicated. Therefore, it is important to study the evolution law of ice plug under the influence of bridge pier to prevent ice loss. The research methods of ice slug in rivers at home and abroad can be roughly divided into numerical simulation. Prototype observation and experimental research. Based on the analysis of the current research situation at home and abroad, the evolution of straight and curved ice plug is studied experimentally. The evolution of ice plug is divided into two stages: initial accumulation stage and late thickening stage. The two kinds of critical forms are affected by initial ice flow rate and initial velocity of ice, but not by pier and pier width, and the velocity of ice accumulation, the increment of water level and the distribution of ice thickness in the initial accumulation stage are all affected by the ice flow. The initial velocity of flow and the depth of clear income changed, and the increase in water level and thickness of ice in the later thickening stage also changed with the change of initial velocity of flow and the depth of 249 _person1#. The influence of pier on the accumulation velocity of ice plug is obvious, but the influence on water level and ice thickness is weak.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.3

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