新型空心块体促淤堤断面波浪特性试验研究

依据长江口南汇边滩促淤工程的波浪条件及物理模型试验方法对新型空心块体促淤堤的断面波浪特性开展研究,结果表明:1)单质量3 t的空心四面块体促淤堤堤身孔隙率约为66%;2)波能消减率随着堤身高度的增加线性增加,波高消减率随堤身高度增加的变大速率较波长消减率平均快4倍以上;3)与传统抛石加护面块体促淤堤相比,空心四面块体促淤堤具有"堤身对地基压载显著减小"、"施工简便"、"强风浪作用下生存力强且修复简便"以及"有利于重复利用"等优点;4)提出了一种特定条件下的空心四面块体促淤堤的临界稳定断面形态,在该临界断面条件下,每100 m促淤堤块体数量约为3 210,水位较低时其消浪效果较传统抛石加护面块体促淤堤略差,但水位较高时其消浪效果接近甚至显著超过传统促淤堤。

Experimental study on wave characteristics of hollow tetrahedron siltation embankment's section

According to the wave conditions of Nanhui siltation engineering located in the Yangtze River estuary,this paper studies the wave characteristics of the section of hollow tetrahedron siltation embankment by physical model test.Test results show that:1) The porosity of embankment is about 66%,when the weight of each hollow tetrahedron is 3 t; 2) The reduction rate of wave energy increases linearly with the increase of embankment height,and the increasing rate of the reduction rate of wave height is averagely 4 times faster than that of wave length with the increase of embankment height;3) Compared with traditional siltation embankment which is composed of riprap and armor block,the hollow tetrahedron siltation embankment has many advantages such as significantly reducing the ground forces from the dike,simplifying construction and repair work,a strong ability to survive under strong storm action and reuse; 4) A critical stable cross-section shape of hollow tetrahedron siltation embankment under certain conditions is proposed.Under this shape condition,every 100 m of siltation embankment consists of about 3 210 blocks,the wave reduction effect of which is slightly worse than that of traditional siltation embankment at low water levels,while the effect is close to or even significantly better than that of the traditional one at high water levels.