Dimensionless critical shear stress evaluation from flume experiments using different gravel beds
Dimensionless critical shear stress evaluation from flume experiments using different gravel beds
复制标题
使用不同砾石床的水槽实验进行无量纲临界剪应力评估
DOI：
10.1002/esp.3290190608
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发表时间：
1994
影响因子：
3.3
通讯作者：
F. Petit
中科院分区：
文献类型：
--
作者：
F. Petit
使用四种不同的砾石床（D50 + 12-39 毫米）和一系列标记颗粒（10-65 毫米）进行水槽实验。当标记颗粒发生初始运动时，根据摩擦速度评估剪切应力。产生了两种方程：第一个用于初始运动的阈值，第二个用于广义运动。即使材料分类相对较好，Andrews (1983) 提出的 0c + a(Di/D50)b 类型的方程也适用。然而，对于初始运动，a 和b 的值较低（分别为0·050 和-0·70）。广义运动需要更高的剪切应力（a + 0·068 和 b + -0·80）。
床层材料的 D90 和 y0（床层粗糙度参数）也用作代替 D50 的参考值。它们产生的值低于自然溪流，主要是因为水槽中使用的材料更好地分类：集群不太发达，河床粗糙度较低。
Flume experiments were conducted using four different gravel beds (D50 + 12–39 mm) and a range of marked particles (10–65 mm). The shear stresses were evaluated from friction velocities, when initial movement of marked particles occurred. Two kinds of equations were produced: first for the threshold of initial movement, and second for generalized movement. Equations of the type 0c + a(Di/D50)b, as proposed by Andrews (1983) are applicable even if the material is relatively well sorted. However, the values of a and b are lower (respectively 0·050 and -0·70) for initial movement. Generalized movement requires a higher shear stress (a + 0·068 and b + -0·80).
D90 of the bed material and y0 (the bed roughness parameter) were also used as reference values in place of D50. They produced lower values than in natural streams, mainly owing to the fact that the material used in the flume is better sorted: clusters are less well developed and the bed roughness is lower.