Research On Traffic Capacity Of Single Lane Waterway Based On Ship Speed Variation

The traffic capacity of waterway is a crucial index to evaluate the ability of ships to dredge waterway,and it is also an important basis for waterway planning and design.In recent years,the increasing demand for Marine transportation has brought great challenges to the organization of vessel traffic flow.As an important import and export channel in Bohai Bay,Changshan waterway has made great contributions to the throughput of ports in Bohai Bay.This dissertation studies the influence of ship speed variation on traffic capacity of Changshan waterway,obtains the traffic rules for reference,improves the navigation efficiency and safety of busy waterway,and provides decision support for ship operators and traffic management personnel of waterway.In this dissertation,a simulation model of ship traffic flow is established based on the statistics on the information of Automatic Identification System(AIS)of Changshan waterway,extracting and analyzing the characteristics of ship traffic flow,such as law of ship arrival,ship speed and ship length.Ships are randomly generated by the distribution law of ship traffic flow characteristics.The ship movement updating rules are set down,including determining the acceleration time by the difference in velocity and distance between ships during the acceleration,and determining the deceleration time by establishing a ship domain model through visualizing the relative positions between ships,so as to simulate the fluctuation of ship speed.By comparing the actual situation with the simulation results,the rationality of the model is verified.The results show that the simulation model can well reflect the behavior characteristics of ships in the channel.Through the definition of traffic capacity and the modification of randomization probability,the maximum traffic capacity in the target channel is estimated to be 27.8 ships per hour.By setting the average passage time and the deceleration index as the index of efficiency evaluation and risk evaluation respectively,it shows that the increase of traffic volume will make the average passage time slightly increase,and the deceleration index significantly increase.