Development of Procedure Ship Collision Load Estimation Procedure based on Reliability Analysis

Abstract

It is necessary to establish criteria deciding design loads from probability distribution of vessel collision load for bridge design based on load-resistance factor design method (LRFD) coping with ship-bridge collision. This study has adopted annual probability of exceedance for probability distribution of vessel collision load as criteria to decide design load. Reliability analysis method for estimating probability of failure is applied to define appropriate level of annual probability of exceedance. It has been decided the probability distribution of vessel collision load considering influence variables of collision conditions, and the probability distribution of structural resistance using P-M interaction diagram of critical section as a limit state and statistical property of resistance. When obtaining structural response from vessel collision load, time history analysis is conducted for considering dynamic effect of collision load. From this study, procedure of bridge reliability analysis for vessel collision load has been formalized. The results of numerical examples applying procedure of reliability analysis for vessel collision load could prescribe the reliability index depending on the annual probability of exceedance. Based on this study, dynamic effect due to vessel collision with bridge is required to be considered and from this procedure, it is possible to calculate more precise vessel collision load than the existing deterministic method.