Research On The Influence Of Ship Collision Prevention Device On Ship Navigation In Curved River Section In Mountainous Area

Mountain rivers have turbulent water flow,large water level drop,and complicated navigation conditions.Due to various factors,the bridge piers and the water flow have a certain oblique angle during the construction of the bridge,which changes the water flow conditions in the bridge area and further increases the risk of ship collision.This thesis studies the effects of ship collision prevention devices on the wading bridge piers of navigable bridges in mountainous areas on the navigation of ships.Common bridges,ship collision prevention devices,characteristic oblique angles,and typical navigable ships in the bridge area are studied as the research objects.The impact on ship navigation.In order to eliminate the hidden hazard of ship-bridge collision during the development of land and water transportation,provide reference for the anti-collision design of navigable bridges in mountainous areas and ship maneuvering and navigation,and provide support for improving the navigation guarantee service level of waterways and improving the ability of bridge collision avoidance.Theoretical and practical value.The main research contents of this paper are as follows:(1)Through the analysis of ship-bridge collision accidents at home and abroad,summarize the current research status of ship-bridge collision and changes in water flow conditions caused by bridge piers on ship navigation,and put forward the necessity of pier bridge fortification of curved river sections in mountainous areas in combination with national safety production requirements.Determined the safe distance and trajectory prediction method for ships sailing after fortification;(2)Based on the AASHTO code,a ship collision risk analysis was carried out on a navigable bridge in a mountainous river section by numerical simulation.The analysis found that the wading piers of the bridge had insufficient collision resistance,and proposed fortification and proposed a fortification plan;(3)Through model tests,study the influence of bridge piers before and after fortification on ship navigation under different skew angles and different ship pier spacing conditions.The study found that the greater the skew angle,the greater the deflection angle of the ship;the greater the ship pier spacing,the less the impact on the ship’s travel.When the ship pier spacing is greater than or equal to 3D,there is almost no impact on the ship’s navigation.Combined with the ship sailing test,a fitting formula for predicting the trajectory of the ship is proposed to provide a reference for the active bridge avoidance of ship collision;(4)Using numerical simulation methods,study the width of turbulence near the piers before and after the bridge piers under different skew angles;analyze the force characteristics of ships under different ship pier spacing and skew angles,and determine the safe width of navigation after the bridge piers are fortified.To provide reference for ship navigation;(5)Through physical model test and numerical simulation analysis,the safe navigation distance of the ship before and after the pier fortification is preliminarily determined,and a reasonable navigation aid plan for the ship before and after the pier fortification is proposed in accordance with the requirements of the regulations.The research results of this paper can provide references for the collision avoidance design of navigable bridges in mountainous areas,as well as the design and planning of wading bridge piers of bridges and the navigation and driving of ships in the bridge area.