岚皋改河造地工程河宽方案及冲刷和防护研究

发布时间：2018-04-18 11:43

本文选题：改河 + 河宽方案　；参考：《长安大学》2014年硕士论文

【摘要】：改河造地就是在条件适宜的地方开挖新河道，修筑新路堤，将河流改道，在老河床和老河湾内造地，以达到增加优质土地的目的。河道改造是一项复杂的工程，往往涉及到截弯取直，新修河堤。沿河路堤作为路基的一种特殊形式，常常见于山区沿河岸半填半挖路段或修筑于宽阔的河漫滩上，其一侧临水，，往往成为山区河流的堤岸。沿河路堤在水流冲击、淘刷和侵蚀作用下容易遭到破坏，特别是在洪水暴发的时候，路基边坡坡脚极有可能被冲刷淘空，最后造成路基大规模坍塌，公路水毁，行车安全受到严重的威胁。因此，研究河道水流及堤岸冲刷情况对于提出经济有效的防护措施，防治公路水毁具有重要的意义。本文总结了沿河路堤构筑物和凹岸路堤冲刷以及减冲防冲措施的国内外研究现状，依托岚皋改河造地工程，通过模型实验的方法进行了下面的研究：首先，研究了定床20年和30年洪水重现期下，改河段水位和水流速度随河宽变化的规律，发现河宽由60m向70m、80m向90m变化时，水位和水流速度下降的幅度较大，河宽由70m向80m变化时，水位和水流速度下降不明显。其次，研究了河宽变化时，造地所产生的经济收益：河宽每减少10m，造地的经济收益为760万元。综合考虑技术与经济因素后，最终选择方案三、四即70m、60m河宽方案为初步方案，接着研究了动床20年和30年重现期下，改河段河道的冲刷与淤积情况，综合考虑危险河段水流速度和后续防护措施后，最终选择了70m河宽方案。再次，根据设计规范确定了改河段沿河路堤的高度，提出了16~24断面沿河路堤和50~62断面沿河路堤的防护建议和措施，确定了48~49断面之间设置丁坝的长度为20m，并且进行了防护效果的实验验证。最后，从能量的角度，分析了改河段出口处顶冲消能，得出顶冲段之后，水流能量较之前减少了12.5%。
[Abstract]:In order to increase the quality of land, it is necessary to excavate new river courses, build new embankments, divert rivers and make land in the old river bed and the old river bay in order to increase the quality of land.River course reconstruction is a complex project, which often involves cutting and bending straight and building new embankments.As a special form of embankment, embankment along the river is often found in the mountain areas along the banks of the half-filled and half-dug section or built on the broad floodplain, its side of the water, often become the banks of mountain rivers.Embankments along the river are vulnerable to destruction under the impact of water flow, scouring and erosion, especially when floods break out, the foot of the slope near the roadbed is likely to be washed away and emptied, resulting in the collapse of the roadbed on a large scale and the destruction of the highway.There is a serious threat to traffic safety.Therefore, it is of great significance to study the river flow and embankment erosion in order to put forward economic and effective protection measures and prevent highway water damage.This paper summarizes the current situation of research on erosion of embankments along the river, erosion of concave embankments and measures to reduce erosion and erosion at home and abroad, and carries out the following research with the method of model experiment, relying on the land reclamation project of Langao River.First of all, the variation of water level and flow velocity with river width is studied under the recurrence period of fixed bed for 20 years and 30 years. It is found that when the river width changes from 60 m to 70 m to 90 m, the decrease of water level and flow velocity is larger.When the width of the river changes from 70 m to 80 m, the water level and the velocity of water flow do not decrease obviously.Secondly, the economic benefit of land reclamation is studied when the river width changes: if the river width is reduced by 10 m, the economic income of land reclamation is 7.6 million yuan.After taking into account the technical and economic factors, the third and fourth schemes, i.e. 70m 60 m river width scheme, were selected as the preliminary scheme. Then, the scour and siltation of the river channel in the changing reach were studied under the recurrence periods of 20 years and 30 years of moving bed.After considering the flow velocity of dangerous reach and the subsequent protective measures, 70 m river width scheme was finally selected.Thirdly, according to the design code, the height of the embankment along the river is determined, and the protection suggestions and measures for the embankment along the river with section 16024 and section 50Y62 are put forward.The length of the spur bar between section 48 and 49 is determined to be 20 m, and the protective effect is verified experimentally.Finally, from the point of view of energy, the energy dissipation at the outlet of the reformed reach is analyzed, and it is concluded that the energy of water flow decreases by 12.5% compared with that of the previous section.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV85

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