渠江丹溪口航道整治方案优化数值模拟

Numerical simulation for optimization of channel regulation scheme for Danxikou in the Qujiang River

丹溪口滩险治理是渠江航道整治的关键性工程。草街电站成库后水位上升及洪水冲刷导致江心洲左支汊发展和岸坡崩塌,严重危及右岸航槽稳定以及左岸居民财产安全。拟采取护岸、封汊、挑流和固滩的措施加以整治,提出了4个整治布置方案。采用二维水流数模和极限冲深公式对各个整治布置方案开展了多级流量计算,通过流速、流向和冲刷深度等指标进行综合比较,优选推荐整治方案:顺直斜坡式护岸阻止丹溪口左岸持续崩塌,锁坝防止左汊进一步变深变宽,江心洲头设置鱼嘴形护坝减小冲刷。研究成果可为渠江丹溪口航道整治工程设计提供科学依据。

Regulation of the Danxikou rapids is a key project for the regulation of the Qujiang channel.The rising water level of Caojie Hydropower Station after impoundment and flood scouring lead to the development of the left branch of the river island and the collapse of the bank slope,consequently seriously endangering the stability of the navigation channel along the right bank and the property safety of residents on the left bank.This paper proposes building a revetment,enclosing the branch,flipping,and consolidating the beach as regulation measures and puts forward four regulation layout schemes.It calculates the multi-level flow of each regulation layout scheme with a two-dimensional numerical flow model and the maximum scouring depth formula.Then,it provides an optimal recommended regulation scheme through a comprehensive comparison according to the indexes of flow velocity,flow direction,and scouring depth.Specifically,the straight slope revetment prevents the continuous collapse of the left bank of Danxikou,the closure dam prevents the left branch from further deepening and widening,and the fish mouth revetment set at the head of the river island reduces scouring.The research results can provide a scientific basis for the design of the channel regulation project for the Danxikou section of the Qujiang River.