Abstract: To address problems such as long waiting time for ships and low passage efficiency during maintenance periods of the Three Gorges-Gezhouba Dam lock, a lockage scheduling model is developed according to the scheduling requirements of the Three Gorges-Gezhouba Dam lock. The lockage scheduling problem is decomposed into three subproblems: chamber arrangement, lockage assignment and timetable optimization. According to the characteristics of the model, the Bottom-Left algorithm, the lockage assignment algorithm considering navigation equilibrium and the timetable optimization algorithm based on adaptive bald eagle search are established to solve the sub-problems, respectively. In such lockage scheduling problem during maintenance periods, two scenarios including dynamic and static scheduling are analyzed according to the congestion level of ships awaiting lockage. Finally, actual historical data of the navigation from the Three Gorges-Gezhouba dam lock are used for comparing the optimization results of the original and modified bald eagle search algorithms. Results show that in a scheduling cycle, the average waiting time of ships can be reduced by about three hours, the average utilization rate of lock chambers can reach over 75%, and the ship throughput can be increased by six ships.

Key words: Three Gorges-Gezhouba Dam, co-scheduling, lock maintenance periods, bald eagle search algorithm optimization, lock chamber arrangement, lockage assignment