When the sediment inflow in the upper reaches of a river is less than the sediment carrying capacity of the current,the erosion effect of the current on the river bed is strengthened,and continuous downcutting occurs.Laying protective nets to form anti-scour erosion foundation can effectively inhibit the continuous cut-ting of river bed.However,the downstream pit affects the stability of the protection network itself,and the basic idea to solve the problem is to construct the superposition protection of the cascade protection network to form the overall effect of protection.Through 20 groups of indoor water tank tests,the protection of cascade protec-tion net on upstream river cutting is studied.The results show that compared with the single stage protection network,the river bed protected by the cascade protection network reaches the equilibrium faster,and the e-quilibrium cut depth is significantly reduced.Although the anti-scour protection efficiency of river bed de-creases with the increase of flow intensity,the protection efficiency of cascade protection network is obviously higher than that of single stage protection network.When the flow intensity is the same,the protection efficien-cy of the cascade protective net decreases with the increase of the spacing.At high flow intensity,when the spacing of the network is slightly larger,the superposition protection between the network is ineffective,and the protection efficiency is equivalent to that of the single stage protection network.
关键词
河床防护/梯级防护网/下切深度/防护效率
Key words
River bed protection/Cascade protection net/Cutting depth/Protection efficiency
维普
万方数据