波浪作用下沙纹床面上底部剪应力的实验研究

Experimental investigation on the bottom shear stress of the sand ripple bed under wave action

在沙质床面上传播的波浪当其强度超过一定条件时,将使沙质床面的形态发生变化而形成沙纹床面,沙纹床面上的底部剪应力与平床面上的底部剪应力有不同的形成机理。而沙纹床面上底部剪应力的研究是波浪沿程衰减和输沙研究的基础。本研究成功地实测了沙纹床面上的底面剪应力,并根据实验成果给出了沙纹床面底部摩阻系数和剪应力的计算公式。

If the strength of travelling wave on the sandy bed exceeds certain value , it will alter the bed pattern and the sand ripple bed will be formed. The formation mechanism of the bottom shear stress on the sand ripple bed differs from that on plan bed. Investigation of bottom shear stress on sand ripple bed is essential to the investigation of wave attenuation along travelling path and sediment transport, therefore, this subjuct has an important significance. In this investigation, the bottom shear stress is measured successfully, and formulas of the bottom friction factor and the shear stress are obtained from these experiment data.