Study On The Prevention And Control Of Sedimentation In The Entrance Area Of The Downstream Approach Channel Of Shiplock

In recent years,under the overall plan of the development of the high-grade waterway of the Huaihe river system,the shipping industry in Henan province has developed rapidly.Shaying river,as the main navigable river section in Henan province and the largest tributary of the Huaihe river,after years of resumption of navigation operation,the problems of obstructing navigation occurred in the control projects on the route,which affected the ability of ships to pass through the locks and restricted the influence of shipping on the economic development of the hinterland.It is of great significance to improve the navigation capacity of shaying river by analyzing the causes of sediment deposition in the entrance area of the downstream approach channel of the lock and proposing the solutions.This paper is that based on the waterway upgrading and reconstruction project from zhoukou to provincial boundary of shaying river,in view of the shaying river Shen Qiu hubs downstream area of sediment deposition at the entrance of the approaches to problems,using the hydraulic physical model tests of 1:65,through in the area at the entrance of the diversion dike head and front introduction of jet,the normal water 1,2,highest navigable water,once every five years floods,poor water to water analysis,five kinds of typical design condition after the introduction of research in jet to lock the downstream area at the entrance of the approaches to the effect of the flow regime and dredging sediment prevention effect,provide a reference for prevention and control of similar problems in inland waterways plains.The main research results are as follows:(1)The sedimentation at the entrance of the approach channel in the downstream of the lock is mainly composed of the coarse sediment flowing back to the entrance area and the extra-heavy sediment flowing through the approach channel.(2)The effect that the measures of extending the length of diversion dike under the existing design pattern of diversion dike are adopted to reduce the silting in the entrance area of the downstream approach channel of the hub is not obvious,and the actual construction cost is high,so it is not recommended to use.(3)When the jet flow of sufficient velocity is introduced,it can effectively prevent the abnormal weight flow from entering the approach channel and damage or compress the range and strength of the backflow zone to a certain extent.When the downstream water depth is certain,the greater the strength of the introduced jet,the better the compression or destruction effect of the backflow zone will be.When the strength of the introduced jet is constant,the compression or damage effect of the jet on the backflow area becomes less and less obvious with the increase of the water depth downstream.When the strength of the incoming jet is certain,the effect of the longitudinal arrangement of the jet at the front end of the approach channel gate is better to prevent the intrusion of the abnormal weight current into the approach channel.When other conditions remain unchanged and the flow strength is large,when the jetting head is arranged at 45 °,the effect of damaging or compressing the backflow area of the inlet gate is better.When the flow strength is small,the effect of damaging or compressing the backflow area of the inlet gate is better when the jet is arranged vertically at the front of the inlet gate.(4)When the control sluice discharges water,when the main stream of the river goes around the diversion dike head and meets the static water flow in the approach channel,a strong turbulent mixed water flow occurs.The flow pattern in this area is complex,and the flow velocity and direction are irregular.When the disturbance flow is introduced,the turbulence intensity of the flow in the backflow zone can be weakened to some extent and the backflow zone can be reduced.