Mathematical Model Study On Waterway Regulation Of Wuming Beach With Rapid And Shallow Groups,Lancang River

With the rapid development of the Lancang-Mekong cooperation,the in-depth implementation of the strategy for the development of the western region and the continuous improvement of people's living standards,the demand for waterway passengers and freight is increasing.The original V-class navigation standard in the lower section of the Lancang River cannot fully meet the needs of shipping.The channel scale needs to be further improved.The Wuming Beach section of the Lancang River has a high risk density,serious navigational obstacles,complex beach risk characteristics,and complex boundary conditions,which makes it difficult to regulate,so it is necessary to carry out research.In this paper,a two-dimensional flow mathematical model and a mathematical model of ship maneuvering motion are used to study the obstacle navigation characteristics and regulation measures of the Wuming Beach groups.The main research contents and achievements are as follows:(1)The hydrological characteristics and riverbed evolution of the Wuming Beach section were analyzed:Since 2013,the reservoirs of Nuozhadu and Jinghong Power Stations have been jointly dispatched,and the discharge flow is generally between 800and 3300 m~3/s.Therefore.The river section except the Xiuhua beach is a shoal.The other riverbeds are composed of bedrock and large blocks of rock,and the riverbed generally does not change greatly.The Xiuhua beach bed is mainly composed of pebbles,and the riverbed has certain changes in erosion and siltation.(2)A planar two-dimensional flow mathematical model and a ship maneuvering mathematical model for the Wuming Beach section of the Lancang River were established:Based on the measured data such as water level and velocity of it,a mathematical model of planar two-dimensional flow mathematical model is established.Based on the MMG model,a mathematical model of ship maneuvering motion for a 500t cargo ship was established and validated.(3)Based on the calculation of the characteristics of the water flow in the beach group and the plane morphology,the characteristics of the beach,the beach and the most violent flow are analyzed.A total of five shoal sections in the study section do not meet the design channel scale.The overall situation is mainly urgency and unimpeded navigation,followed by bending and shallow.The overall situation is urgent,impediment to navigation,bending,shallow.The beach flow and the most violent flow of the Xigua Beach and the Wuming Upper Beach are 3500m~3/s.The flow of the Wuming Beach into the beach is 820m~3/s,and the most violent flow is 1650m~3/s;The beach flow and the most violent flow in the Mengsong Beach are both 820m~3/s.(4)The interaction between the beach risks of the beach group was studied,and the idea of rectification of the beach group was proposed:(1)Expanding the water area of the shoal of the Wuming beach by clearing the reef,taking into account the design of the channel scale,ensuring the basic navigation flow conditions,and improving the flow pattern;(2)Maintaining the stability of the navigation channel and enhance the sediment transport capacity of the embroidered beach pebble shoal by dredging and damming;(3)Minimize the interaction between the beaches based on the combination of drowning one by one and segmentation digestion;(4)Satisfying the basic navigation conditions is the first priority,and expanding the remediation effect when conditions permit.(5)Through the optimization calculation of the series of schemes,a scientific and reasonable engineering remediation plan is proposed:Firstly,the research on expanding the drainage section and the drowning plan was carried out,and then six comprehensive remediation plans and two partial optimization plans were studied.However,only the remediation plan five or six can meet the 500t representative of the cargo ship sailing on the beach.By comprehensively analyzing the indicators of the two remediation plans,the change of the water level along the way,the comparison of the upstream parameters of the ship,the amount of clear reef works,etc.the remediation plan 5 is selected as the recommended plan,and the remediation plan 6 is selected as the mandatory plan.