基于河道行洪能力的护岸糙率影响分析

Analysis of Impact of River Revetment Roughness based on Flood Discharge Capacity

文章利用三棱柱砖块和仿真草皮模拟河道生态护岸,采用水槽试验揭示了护岸糙率在变底坡和变流量下工况下的变化规律,然后通过数值模拟研究了护岸糙率于不同宽深比以及非均质流条件下对水面线的影响。研究表明:河道综合糙率符合对数分布规律,水深越深其值越大,护岸糙率受底坡或流量的改变影响较低;随护岸糙率的增大,非均匀与均匀流情况下河道水深均不断增加,沿程水深与沿程综合率在非均匀流条件下呈正相关;宽深比较小的河道水深受护岸糙率较大范围的变化影响较大,而宽浅河道行洪能力受护岸糙率变化的影响较低。

In this paper,three prism bricks and simulated turf were used to simulate the ecological river revetment.The flume test was used to reveal the variation law of the revetment roughness under the condition of variable bottom slope and variable flow rate.Then,the influence of the revetment roughness on the water surface line under different width-depth ratios and heterogeneous flow conditions was studied by numerical simulation.The results show that the comprehensive roughness of river channel conforms to the logarithmic distribution law,and the deeper the water depth is,the greater the roughness value is,and the influence of the change of bottom slope or flow rate is less.With the increase of the roughness of the revetment,the channel depth increases in both non-uniform and uniform flow conditions,and the depth along the river is positively correlated with the comprehensive ratio along the river under the non-uniform flow conditions.The river channel water with small width and depth is greatly affected by the change of bank roughness in a larger range,while the flood discharge capacity of wide and shallow river channels is less affected by the change of bank roughness.