黑龙江孙吴江段岸滩防护治理数学模型计算分析

Numerical modeling study on the influence of land protection project on the Sunwu Reach of the Heilongjiang River

黑龙江孙吴江段受水流剧烈冲刷严重危害沿岸安全。通过构建孙吴江段三维非结构网格水流泥沙数值模型,研究不同频率洪水条件下,孙吴江段岸滩防护工程对水力特性的影响,预测江段冲淤演变趋势及其防护前后的变化。研究结果表明,防护工程对孙吴江段水位与流速的影响随着洪水流量的增加而减小,二十年一遇洪水条件下,防护工程附近区域水位抬升普遍不超过2 cm,主河道内流速变化不超过0.1 m/s。修建防护工程后,孙吴江段内的中方滩、岛边岸受到保护的位置稳定性更好,综合治理技术发挥了明显的防护作用。

Series scour of the Sunwu Reach of the Heilongjiang River endangered the homeland security and people′s lives and property. A three-dimensional unstructured grid flow and sediment numerical model of the Sunwu Reach are constructed to study the impact of the Sunwu Reach land protection project on hydraulic characteristics under different frequency flood conditions and to predict the evolution trend of scour and deposition. Results show that the impact of the protection project on the water level and flow velocity of the Sunwu Reach decreases with the increase of the flood flow. Under the condition of a flood in 20 years, the water level in the vicinity of the protection project generally does not rise by more than 2 cm, and the flow velocity in the main river channel changes no more than 0.1m/s. After the construction of the protection project, the protected scouring positions of the beach and island bank in the Sunwu Reach are more stable.