通过破坏性试验和冲淤水槽试验,对四面六边透水框架防护措施的稳定性进行研究.破坏性试验研究防护层破坏发展过程和破坏临界条件下来流摩阻流速与防护层参数之间的关系,冲淤试验研究防护层附近床面的冲淤变化特性.结果表明,防护层的稳定性与其布置形式及参数有关.流线型迎流面有利于框架群稳定.破坏临界条件下,来流摩阻流速与框架群密度呈正相关关系;且随来流水深与框架群厚度比值的增大先增大后趋向定值,分界点比值约为4.相对于实心体边缘的集中淘刷,框架群表现出"冲刷后移"现象,对边缘处的稳定相当有利;框架群内部产生的淤积现象亦增加稳定性,建议将防护对象置于框架群内部淤积区域,以达到更好的防护效果.
A flow-altering armoring countermeasure device, frames in the shape of tetrahedrons, was tested by destructive tests and scour tests in a laboratory flume. Destruction development process and relationship between the friction velocity and layer parameters in critical destabilization condition of tetrahedral frames were investigated by destructive tests. Erosion and deposition characteristics near the frames were studied by scour tests. The destructive tests show that the frames stabilities are associated with layout form and parameters. The streamlined arrangement may be good for the frames stabilities. Under critical destabilization condition, friction velocity increases with increasing the layout-density of frames. As the ratio of flow-depth to frame-layer-thickness increases, the friction velocity increases and then becomes stable when the ratio is larger than 4. The scour tests indicate that unlike the riprap layer, the scour positions are moved backward in the edges of frames. The above phenomena and sedimentation inside the frames are conducive to frames stabilities. The protected object could he placed in this sedimentation area to achieve better protective effect.