Research On Remote Sensing Method For Ship Collision With Bridge Pier In Pearl River Water System

The Pearl River water system in Guangdong Province is full of navigable rivers,with developed road traffic and numerous cross-river bridges;With the development of social economy,the number and scale of shipping vessels have gradually increased;the existing cross-river bridges are mostly built in the last century and the headroom is not large.The conventional bridges increase the risk of the bridges being hit by ships.This paper explores the monitoring and sensing methods of ship collision with bridge piers by combining the theoretical analysis,digital simulation,and test verification for large-scale and wide-scale bridges.The main research work is as follows:(1)Comparing the three methods of installing camera,energy dissipation warning floating ring and vibration sensor to detect the impact of the pier on the ship;For the conventional cross-river bridges with large volume and wide range in the Pearl River,from the perspective of the bridge manager’s need to know the time,location and estimated damage degree of the accident in a timely manner,based on the comprehensive consideration of mature technology,timely credibility and economic practicality,it is proposed to the acceleration sensor is installed on the top of the pier to detect the impact event of the ship.(2)Taking the representative bridges and ships in the Pearl River system as the object,the finite element simulation was used to simulate and analyze the process of the ship impacting the pier.The sensitive position of the acceleration response of the pier when it is impacted,the number of sensors installed,and the law of the acceleration response of the pier under the conditions of different ship masses,ship speeds,and impact heights are proposed,and the fitting estimation formulas of impact force,impact height and acceleration response are proposed.(3)Three mechanical models of ship bridge impact systems with different degrees of simplification were established,and the theoretical relationship between impact force,impact height and pier top acceleration was derived based on the principle of conservation of energy;For the plexiglass continuous beam bridge model,an experimental study on the impact of the pier on the bridge was carried out.The influence law of impact speed,impact height and other parameters on the acceleration of the top of the pier structure was tested,and the feasibility and effectiveness of the proposed method of ship collision with the pier perception were verified.(4)Based on the elastoplastic damage finite element method,the damage degree of the double-column bridge pier subjected to ship impact was simulated and analyzed.The failure modes of the pier under different impact conditions were studied.A rough estimation method for grading the damage degree of the pier was proposed.A table relationship between the known impact height and the peak acceleration of pier top is used to roughly estimate the damage degree of the pier.