Dynamic Inversion Model of the Mooring Force on a Floating Bollard of a Sea Lock

Abstract

Sea locks that connect inland canals and rivers to the open sea are crucial links that ensure the efficient navigation of ships. Floating bollards (FBs) are significant components of sea locks, and they are affected by factors such as large ships, speed of entry, and irregular mooring lines coupled with corrosion by chloride salts from seawater intrusion from the environment. These factors aggravate damage to metal structures, which seriously threatens the safety of FBs. Overloading of FBs by mooring forces caused by the illegal use of FBs for the braking of large ships that enter locks at excessive speed is the main cause of structural damage and overload failure for FBs. Controlling the dynamic mooring force acting on the FB is an important prerequisite to ensure the safe passage of a ship through a lock. It is impossible to perform real-time monitoring of the magnitude and direction of the mooring force on an FB by installing load-measuring equipment on the mooring line. Therefore, in this study, the structure of an FB in a sea lock project was taken as an example, and the mathematical relationships between the strain in the load-sensitive area of the FB and the mooring force and the mooring angle were quantified. A dynamic inversion model of the ship mooring force on an FB was proposed. This model used real-time feedback from the strain signal in the load-sensitive region of the FB structure to obtain information about the mooring force. The accuracy of the model was verified by conducting tests with a physical model of the topside structure of the FB and comparing the predicted results with the test data. The research results can lay a theoretical foundation for real-time monitoring of the structural response of an FB under the action of mooring forces and promote the development of intelligent methods for the operation and maintenance of a sea lock, which have important scientific significance and engineering value.