Research On Design Method Of Ship Collision Prevention Facilities Based On Bridge Collapse Probability

With the rapid development of my country’s transportation industry,as an important infrastructure in the modern transportation field,there are more and more bridges across the port area and navigable rivers.At the same time,the number of ships in my country is also increasing year by year,and it is developing in the direction of large-scale and rapid development,resulting in a sharp increase in the number of bridge collapse accidents due to ship collisions.At present,the main measure to reduce the risk of bridge ship collision is to install protective devices for the pier,thereby reducing the impact force of the ship collision transmitted to the pier,thereby reducing the risk of bridge collapse.The method of judging whether a bridge collapses after being hit by a ship is mainly by comparing the maximum impact force of the ship with the impact force of the pier,and the fact that the ship hits the bridge is a probabilistic event has not been fully considered.Therefore,how to combine the possibility of a ship hitting a bridge and the reliability of the bridge after being hit by a ship is very necessary to consider whether the bridge has the risk of collapse.In this paper,the ship’s AIS data will be used to analyze the navigation dynamics of ships near the bridge area,and then the three-parameter path integration model will be used to calculate the bridge collision probability.Based on the numerical method and the empirical formula method,the impact force of the ship is analyzed and the collision resistance of the pier itself is calculated to calculate the single collapse probability of the bridge when it is hit by the ship.On this basis,the year when the bridge is hit by the fortified ship is determined based on the risk assessment method Probability of collapse,and design corresponding anti-collision facilities to ensure the safety of the bridge.The main contents are as follows:First,take a Yangtze River Bridge as an example,collect AIS data of the bridge area,analyze the traffic flow of ships near the bridge,statistically analyze the distribution of ship speed in the bridge area,ship tonnage and ship main scale distribution,ship yaw angle distribution To provide actual data support for subsequent research.Second,the three-parameter path integration model is selected and combined with the navigable ships,navigation density,pier size,hydrological data,and channel conditions to calculate the annual frequency of ship impact on the bridge,and evaluate the ship collision risk level of each pier.Third,use the empirical formula and finite element analysis to calculate the impact force of the fortified ship type on the pier in the bridge area,combine the impact force of each main pier,use the AASHTO collapse probability model to calculate the probability of a single ship collision of the bridge,and combine the annual collision frequency to determine Bridge risk level.Fourth,design anti-collision and anti-collision facilities for bridge piers with greater risks.Combined with the situation of the bridge area,design a reasonable anti-collision facility to improve the collapse resistance of the bridge.The finite element analysis was used to calculate the impact force on the bridge after the installation of anti-collision facilities,and the probability of bridge collapse risk was obtained to evaluate the reliability of anti-collision facilities.Through the research in this paper,the actual ship traffic flow in the bridge area is analyzed,and the main characteristics of the ship that affect the bridge collision are obtained,which can provide a certain reference for the local management department.Combining the three-parameter path integration model with the actual AIS data to calculate the ship-bridge collision probability provides a new idea for the future ship-bridge collision risk assessment.Finally,a method for designing anti-collision facilities based on the probability of bridge collapse is proposed.The reliability evaluation of anti-collision facilities by this method not only considers the relationship between the maximum ship collision force and ship collision resistance,but also considers the ship collision with bridge events The possibility of happening.This method can provide a certain reference for the ship collision risk assessment and the reliability assessment of anti-collision facilities in the early stage of bridge design.