桥墩影响下的河道冰塞堆积和壅水位变化试验研究

发布时间：2018-02-10 22:24

本文关键词： 冰塞水位桥墩试验研究　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：冬季,寒冷地区河流易形成冰塞,跨河桥梁及其墩台的存在改变了河道中原有的水流条件和边界条件,使河道中冰塞的形成发生变化。桥墩的存在束窄了河道,冰塞更易形成。冰塞常常导致凌洪灾害,对河流沿岸的社会经济和河流的生态系统造成严重破坏。通常,冰塞壅水是凌洪灾害发生的直接原因,因此研究有桥墩存在时冰塞壅水对高纬度地区的防凌工作具有重要意义。本次冰塞研究通过模型试验进行,为了对比有无桥墩时的冰塞堆积演变和水位增值,分别进行了无桥墩模型和有桥墩模型的水槽试验,对所得数据整理分析得出：无桥墩冰塞平衡时水位变化规律与前人试验结果基本相符,水位增值△H/初始水深ho是随着冰流量Qi／流量Qw的增大而增大并呈线性关系,这种线性关系的斜率从上游断面到下游断面是逐渐降低的,即上游水位增值更大；有桥墩模型时冰塞演变会出现两种结果,即冰塞发展过桥墩和冰塞未发展过桥墩,冰塞发展过桥墩达到平衡时,紧邻桥墩上游断面处流速越大水位增值越小,全观测断面水深越小水位增值越大,桥墩上游上段处直径越大水位增值越小,桥墩上游的中后段和桥墩下游的水位受桥墩直径的影响较小；冰塞未发展过桥墩达到平衡时,全试验观测断面水深对水位增值影响不明显,桥墩上游断面处流速越大水位增值越小。
[Abstract]:In winter, ice jams are easily formed in rivers in cold regions, and the existence of bridge beams and abutments over rivers change the original flow conditions and boundary conditions in the river channels, and make the formation of ice jams in the rivers change, and the existence of piers narrow the river channels. Ice plugs are more easily formed. Ice plugs often lead to flash floods, causing serious damage to the socio-economic and ecological systems along rivers. Generally speaking, ice jams are the direct cause of flash floods. Therefore, it is of great significance to study the ice jam backwater in the presence of bridge piers in high latitudes. In order to compare the ice slug accumulation evolution and water level increment with or without piers, the ice slug study is carried out through model tests. The flume tests without pier model and with pier model are carried out, and the data are analyzed. It is concluded that the variation of water level in the ice plug equilibrium without pier is basically consistent with the previous experimental results. The water level increment H / initial water depth ho increases with the increase of the ice discharge Qi/ discharge QW, and the slope of this linear relationship decreases gradually from the upstream section to the downstream section, that is, the upstream water level increment is greater; When there is a model of bridge pier, there will be two results of ice slug evolution, that is, when ice plug develops over bridge pier and ice plug does not develop bridge pier, when ice slug development reaches equilibrium, the increase of water level near the upstream section of bridge pier becomes smaller. The smaller the water depth of the full observation section, the greater the increment of water level, the larger the diameter of the upper section of the pier is, the smaller the increment of water level is, and the smaller the water level in the middle and lower reaches of the pier is affected by the diameter of the pier, and when the ice slug is not developed beyond the pier to achieve equilibrium, The effect of water depth on the increment of water level is not obvious, and the increase of water level at the upstream section of pier is smaller.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TV133

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