摘要
当河流上游来沙量小于水流的挟沙能力,水流对河床冲刷侵蚀作用加强,发生持续性下切。在河道铺设防护网可形成抗冲侵蚀基面对抗水流冲刷,能够有效抑制河床持续性下切,但其下游的冲坑影响防护网自身稳定,建设梯级防护网叠加保护使防护形成整体效果是解决问题的基本思路。通过20组室内水槽试验,研究梯级防护网对上游河道下切防护。结果表明:相较于单级防护网,梯级防护网保护的河床更快达到平衡,且平衡下切深度明显减小;虽河床抗冲防护效率随水流强度的增大而减小,但梯级防护网的防护效率明显高于单级防护网,水流强度相同时,梯级防护网防护效率随间距的增大而减小;在高水流强度下,网间距略大时,网间叠加防护失效,防护效率与单级防护网相当。
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 cutting 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 protection 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 equilibrium cut depth is significantly reduced.Although the anti-scour protection efficiency of river bed decreases 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 efficiency 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.
作者
王冰炜
郭志学
钱撼
张婧
Wang Bingwei;Guo Zhixue;Qian Han;Zhang Jing(National Key Laboratory of Mountain River Protection and Governance,Sichuan University,Chengdu 610065,China;Sichuan Highway Planning,Survey,Design and Research Institute Ltd.,Chengdu 610041,China;School of Energy and Power Engineering,Xihua University,Chengdu 610039,China)
出处
《吉林水利》
2025年第1期1-6,共6页
Jilin Water Resources
基金
四川省自然科学基金项目,下切型河道柔性防护网防治技术及作用机理研究(2023NSFSC0950)。
关键词
河床防护
梯级防护网
下切深度
防护效率
River bed protection
Cascade protection net
Cutting depth
Protection efficiency
