波浪作用下级配泥沙海滩滩面变化试验研究

砂质海滩的泥沙具有一定的级配，在波浪作用下，滩面泥沙粒径将发生分选，引起海滩质量变化。在水槽中用不同波高和周期的波浪分别对不同级配的沙滩进行作用，探究滩面在波浪外动力作用下的变化规律。结果表明：全级配沙滩在相同波高波浪作用下形成的沙坝型海滩滩型中，破波点向海的区域表层泥沙分选会随波浪周期增大变差；相同周期(T=1.68s)波浪作用下，全级配沙滩在大波高(H=13.2cm)和小波高(H=6.7cm)的波浪作用下分别形成沙坝型和滩肩型海滩，滩面泥沙分选变好；原始沙滩级配与滩面泥沙变化密切相关，同种波浪动力作用下，中细、粗中沙滩沙坝表层泥沙迎波面粗于背波面，粗细沙滩粗颗粒集中在沙坝和滩顶之间。

Experimental study on beach surface variation of graded sand beach under wave action

The sand beach is a depositional system composed of graded sands under the sorting of wave action, which decides the quality of a beach. In this paper, flume experiments under periodic waves with different wave heights are conducted to study the variation in beach sediments under wave dynamics. Results show that the bar type of beach formed by the full grade sediments under the same wave height, and the surface sediment sorting in the area from wave breaking point to the sea is inversely proportional to the wave period. Under the same periodic wave (T=1.68s), the full grade beach will form a sand bar-type beach under the action of big waves (H=13.2cm), and a berm type beach under the action of wavelet high waves (H=6.7cm), and the sediment sorting on the beach surface is better. Under the same wave power, however, the sand bar surface sediment of the middle and fine grade beach and the coarse and medium grade beach is thicker than the back wave; and the coarse-grained sediment of the coarse and fine grading beach is concentrated between the sand bar and the beach top.