Study On The Regulation Measures Of Typical Shallow And Dangerous Shoals In The Upstream Of Yangtze River

Due to the original geological and geomorphic,there are three types of navigation hampering shoals in the upstream of Yangtze river.The characteristics of various types of rapids are different.In general,shallow shoals often characterized by lack of channel dimensions.The rapids often characterized by the large velocity and gradient.This results in the inability of the ship to sail on the beach.And local flow is disordered,navigation conditions are bad so that the ship can not sail safety.this oftenmake the performance of dangerous shoals.To improve the navigation flow condition of the barrier shoal,there are mainly physical model test and mathematical model simulation.In terms of accuracy,this paper make Xiaomi beach as the research object,analyzes and studies the regulation line and waterway regulation measures by means of generalized physical model,theoretical calculation and numerical simulation method.Researching the riverbed evolution law and navigation obstruction.Based on the analysis of the cause of shallow formation and the riverbed evolution,we put forward the renovation principle: improve channel scale and improve the flow conditions by means of dredging and reef,strengthen the transport capacity with the regulation structures.Based on previous remediation,optimizing regulation line,improving project layout,and maintaining the stability of navigation channel.Based on the measured data,the design flow,maximum navigable flow and water level of the experimental reach are deduced.Determining the regulation parameters of shoals,including the elimination of regulation water level indicators,width of regulation line and rectification regulation structures layout.To provide a theoretical basis for the subsequent design and selection of remediation programs.To verify the the water level,velocity,flow and other aspects of the physical model.making the water sediment recognition test,observing the flow velocity,water level,flow ratio in various schemes.And analyzing the flow characteristics of the natural condition of the channel deeply,to provide data support for the remediation of search channel parameters.With the generalized physical model test,testing and researching the proposed scheme.Under the condition of satisfying the navigation flow condition and channel scale,To put forward recommendations of the river based on the principle of small external environmental impact and stable sediment transport capacity.To analyze the channel shatbility furtherly from the angles of the flow velocity,gradient,and eliminating beach trough sediment stability and other aspects in detail.Finally the results show that the scheme can not only achieve the desired treatment effect,but also maintain good stability.