自淤沉管管流特性与垒管结构护岸效应技术研究

发布时间：2019-06-21 02:09

【摘要】：河道崩岸是长江中下游十分普遍和突出的地质灾害,在一定程度上威胁着两岸居民的人生财产安全。目前,对于长江崩岸的治理虽然采取了许多积极的护岸措施,随着工程实践表明,很多护岸方法在一定条件下起到了一定的效果,但依然存在一定的局限性。因此本文拟在现有研究、实践的基础上,探讨一种新的低成本护岸手段。本文调查研究了国内外有关崩岸问题的理论与技术文献资料,整理分析了部分不同类型的护岸工程的特点以及存在的问题,对崩岸机理及引发崩岸的影响因素进行总结归纳。在此基础上提出了自淤沉管与混凝土膜袋综合治理和预防长江崩岸的方法。所谓自淤沉管是一种沉入近岸江底的长管,水流通过长管内部的消能装置,江水挟带的泥沙在管内自然沉降淤积,籍此充填长管增加自重,起到镇重作用。可将一根根长管垒成一个整体形成“垒管结构”,与混凝土膜袋配合使用,既起到替代抛石压重镇脚护岸的目的,又能够适应河床与岸坡变形,使之与河床、岸坡紧密贴合,进一步稳固岸坡,达到护岸的目的,长治高效。本文采用窦国仁泥沙计算理论得出泥沙沉降对水流流速的要求,通过室内模型试验研究确定自淤沙管的减速装置和最佳减速效果的模型尺寸。在此基础上,选用九江市彭泽县棉船镇一长江流段为室外足尺试验地点,验证其淤沙效果。利用FLOW-3D数值模拟软件,模拟分析自淤沉管内部水流的流速和流态变化,进一步探讨自淤沉管的淤沙机理,证明它的减速效果。针对垒管结构形式对周边水流和河床泥沙的影响进行数值模拟分析,探讨了改进垒管结构对周边流体特性和对河床的侵蚀作用,进一步完善垒管结构,为将垒管结构赋诸工程实施提供技术支撑。
[Abstract]:River bank collapse is a very common and prominent geological disaster in the middle and lower reaches of the Yangtze River, which threatens the life and property safety of residents on both sides of the strait to a certain extent. At present, although many positive measures have been taken to protect the bank of the Yangtze River, with the engineering practice, many revetment methods have played a certain effect under certain conditions, but there are still some limitations. Therefore, this paper intends to explore a new low-cost revetment method on the basis of the existing research and practice. In this paper, the theoretical and technical literature on bank collapse at home and abroad is investigated and studied, the characteristics and existing problems of some different types of bank protection projects are sorted out and analyzed, and the mechanism of bank collapse and the influencing factors causing bank collapse are summarized and summarized. On this basis, the comprehensive treatment of self-silting pipe and concrete film bag and the method of preventing the bank collapse of the Yangtze River are put forward. The so-called self-silting pipe is a kind of long pipe which sinks into the bottom of the inshore river. The water flow passes through the energy dissipation device inside the long pipe, and the sediment carried by the river water is naturally settled and silted in the pipe, thus filling the long pipe to increase the self-weight and play the role of calming weight. A long pipe can be formed into a whole "barrier pipe structure", which can be used in combination with concrete film bag, which can not only replace the purpose of bank protection, but also adapt to the deformation of river bed and bank slope, make it closely fit with river bed and bank slope, further stabilize the bank slope, achieve the purpose of bank protection, and achieve the purpose of long treatment and high efficiency. In this paper, the requirement of sediment sedimentation on flow velocity is obtained by using Dou Guoren sediment calculation theory, and the deceleration device of self-silting pipe and the model size of optimal deceleration effect are determined by laboratory model test. On this basis, the Yangtze River flow section of Mianchuan Town, Pengze County, Jiujiang City, was selected as the outdoor full-scale test site to verify the sediment silting effect. By using FLOW-3D numerical simulation software, the flow velocity and flow pattern in the self-silting tube are simulated and analyzed, and the silting mechanism of the self-silting pipe is further discussed, and its deceleration effect is proved. In view of the numerical simulation analysis of the influence of barrier pipe structure on the surrounding water flow and riverbed sediment, this paper probes into the improved barrier pipe structure on the surrounding fluid characteristics and the erosion effect on the river bed, further perfects the barrier pipe structure, and provides technical support for the implementation of the barrier pipe structure.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV861

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