【作者】 陈琴琴；

【导师】 喻国良；

【作者基本信息】 上海交通大学 ， 港口及近海工程， 2008， 硕士

【摘要】 随着我国国民经济的的发展与环保能力的日益加强,各类产沙治理措施的逐渐成效,以及大型水利工程的建设等因素,长江、黄河等大江大河入海泥沙极剧减少,海岸侵蚀后退现象严重。现在的促淤减冲措施除生态措施外,常见的是水工措施,如丁坝、薄墙或薄板及跺等。本论文研究的是一种新型的浮帘式底沙截留促淤装置,该装置主要由捆绑在重梁上的浮帘和安放在床面上的重梁组成,离浮帘下缘一定高度开有过沙窗口。安置在水底的浮帘将水流底部来流导向上部,在浮帘的背水面形成大小漩涡,底沙通过浮帘底部的过沙窗口进入并淤积在该漩涡区中,从而起到河床的底沙截留促淤作用。论文主要在1m宽的水槽中对浮帘底沙截留促淤装置附近的流场和底沙的运动特性进行二维研究,并提出了一种新的简易PIV测速方法。具体对流速、浮帘高度、水深等因素对浮帘倾斜角度和浮帘有效高度的影响进行了研究;研究浮帘回流大小的影响因素;从材料利用率方面,得到浮帘最佳高度和浮帘群的最佳间距;并拟合了浮帘倾斜角度与流速和浮帘相对高度的函数关系。通过动床实验,观察浮帘后方的淤积形态和淤积特性。相对于其他透水和不透水的丁坝(群),浮帘截留促淤装置投资少、见效快、施工简单,对河势干扰和阻力作用都很小,且拆除方便,可广泛应用于滩面促淤、护滩护坡及防冲工程。现有吹泥上滩工程的截留泥沙效率不高,本课题的研究成果如可为工程所用,将会大大提高上滩泥沙的存留率,无疑具有明显的应用意义。因此,本课题将对泥沙促淤基理研究和工程新技术的开发具有重要现实意义。更多还原

【Abstract】 Along with the development of our national economic and the reinforcement of the ability of protecting environment, diversified methods for controlling the sediment having taken effect gradually, and the large-scale water conservancy measures having been constructed, etc. the sediment amount which runs to the ocean from the big rivers like the Yangtse River, the Yellow River etc. has been dramatically reduced and the countermarch phenomenon of coastline is speeding up. Nowadays, there are lots of measures for deposition promotion and erosion control, in addition to the ecological measures, dikes, vanes and many others are widely used.This paper presents a new kind of apparatus for harvesting sediment in flows which is termed as a suspended curtain or harvesting sediment. The curtain was a piece of rectangular sheet,which was shin and light weight. One side was fixed to the bed with a heavy pillar. A rectangular window was opened near the side close to the pillar. This window, termed as sediment-passing-window, allowed moving sediment passing through and reduced the drag force on the curtain exerting by the flow. The pillar was laid onto the bed, which was stable against pulling away by the flow. The curtain diverted the flows to upside, and in the lee of the curtain formed a big and a small flow circulations, and the sediment particles which passed through the sediment-passing-window was filled up in the flow circulation area, accordingly, the aim to trap sediments was achieved. The characteristics around the suspended curtain were investigated in the two dimensional flume which was 1 m wide. A new method to achieve the flow field- simple PIV method was proposed. How the factors such as velocity of flow, the height of curtain and so on affect the slope angle of curtain and the effective height of curtain were investigated. The factors for the flow circulation size of the curtain, the best height of curtain and the best spatial layout between the curtains were also investigated. A function about the slope angle, velocity and relative height of curtain were also drawn up. Finally, preliminary experiments on the movable bed were carried out, and the characteristic of the sediment deposition around the suspended curtain were explored.Compared to the dikes, groins, the device has lots of advantages, such as low cost, quick-acting, simple-constructing, little-disturbing and little-resistance for the flow, and removing convenience. It can be applied to the deposition promotion projects for protecting the beach or bank erosion control.更多还原