Block ramps are hydraulic structures used to control the sediment transport in rivers and to dissipate flow energy. Moreover, they serve as useful structures to maintain and preserve ecological habitat and to facilitate fish migration. In the past, scour features of both protected and unprotected stilling basins of block ramps have been studied for straight river branches. Sometimes, these structures are placed at channel curves where the flow distribution is characterized by a significant asymmetry, resulting in a scour formation in correspondence with the channel bank, that needs to be carefully predicted and controlled to minimize the risk of a structural failure. Apparently, so far there are no studies focusing on the scour mechanism occurring in protected stilling basins downstream of block ramps in river bends. Hence, this paper aims at investigating the effect of stilling basin protection on the scour process under a combination of different hydraulic conditions, block ramp configurations and locations of the protection structure along the stilling basin. To this end, tests were carried out by placing the block ramp in a curved channel and varying both the flow discharge and the downstream tailwater depth. The downstream stilling basin was protected by introducing a rock sill at various distances from the ramp toe. It has been found that the equilibrium scour morphology mainly depends on hydraulic conditions and it is also influenced by the position of the rock sill in the basin. A classification of different morphological configurations is proposed as well. Finally, an empirical equation is provided to estimate the maximum scour depth under the tested configurations.

砌块坡道是用于控制河流中泥沙输送和耗散流动能的水力结构。此外，它们是维持和保护生态栖息地并促进鱼类迁移的有用结构。过去，对于直河支流，已经研究了块状坡道的受保护和未受保护的静止盆地的冲刷特征。有时，将这些结构放置在通道曲线处，其中流量分布的特征是明显的不对称性，从而导致与通道库相对应的冲刷形成，需要仔细地进行预测和控制，以最大程度地减少结构故障的风险。显然，到目前为止，还没有研究集中在河弯块状坡道下游受保护的静水盆地的冲刷机理上。因此，本文旨在研究在不同水力条件，块坡道构型以及沿休耕盆的保护结构位置相结合的情况下，休耕盆保护对冲刷过程的影响。为此，通过将砌块坡道放置在弯曲通道中并改变流量排放和下游尾水深度来进行测试。通过在距坡道脚趾不同距离处引入石基来保护下游的静水盆地。已经发现，平衡冲刷形态主要取决于水力条件，并且还受到盆地中岩基的位置的影响。还提出了不同形态构型的分类。最后，

砌块坡道是用于控制河流中泥沙输送和耗散流动能的水力结构。此外，它们是维持和保护生态栖息地并促进鱼类迁移的有用结构。过去，对于直河支流，已经研究了块状坡道的受保护和未受保护的静止盆地的冲刷特征。有时，将这些结构放置在通道曲线处，其中流量分布的特征是明显的不对称性，从而导致与通道库相对应的冲刷形成，需要仔细地进行预测和控制，以最大程度地减少结构故障的风险。显然，到目前为止，还没有研究集中在河弯块状坡道下游受保护的静水盆地的冲刷机理上。因此，本文旨在研究在不同水力条件，块坡道构型以及沿休耕盆的保护结构位置相结合的情况下，休耕盆保护对冲刷过程的影响。为此，通过将砌块坡道放置在弯曲通道中并改变流量排放和下游尾水深度来进行测试。通过在距坡道脚趾不同距离处引入石基来保护下游的静水盆地。已经发现，平衡冲刷形态主要取决于水力条件，并且还受到盆地中岩基的位置的影响。还提出了不同形态构型的分类。最后，

砌块坡道是用于控制河流中泥沙输送和耗散流动能的水力结构。此外，它们是维持和保护生态栖息地并促进鱼类迁移的有用结构。过去，对于直河支流，已经研究了块状坡道的受保护和未受保护的静止盆地的冲刷特征。有时，将这些结构放置在通道曲线处，其中流量分布的特征是明显的不对称性，从而导致与通道库相对应的冲刷形成，需要仔细地进行预测和控制，以最大程度地减少结构故障的风险。显然，到目前为止，还没有研究集中在河弯块状坡道下游受保护的静水盆地的冲刷机理上。因此，本文旨在研究在不同水力条件，块坡道构型以及沿休耕盆的保护结构位置相结合的情况下，休耕盆保护对冲刷过程的影响。为此，通过将砌块坡道放置在弯曲通道中并改变流量排放和下游尾水深度来进行测试。通过在距坡道脚趾不同距离处引入石基来保护下游的静水盆地。已经发现，平衡冲刷形态主要取决于水力条件，并且还受到盆地中岩基的位置的影响。还提出了不同形态构型的分类。最后，