Research On Capacity Of Long And Steep Upgrade Sections In Extra Long Underwater Tunnels Based On Cellular Automata

For extra long underwater tunnels,in order to achieve a reasonable connection with onshore roads,it is often necessary to increase the size of the longitudinal slope at the entrance and exit sections at both ends of the tunnel,where long longitudinal slope sections form.The poor climbing performance of large vehicles has a huge impact on the capacity of the road section,causing the phenomenon of traffic congestion to repeatedly appear on long and steep upgrade sections in extra long underwater tunnels.Therefore,in order to create a good driving environment,ensure the safety and smoothness of the road,and improve the transport management level of underwater tunnels,it is very necessary to carry out relevant research on the capacity of long and steep upgrade sections in extra long underwater tunnels,find the main factors that restrict its capacity,and propose effective methods.In this thesis,the traffic simulation method is used.Firstly,the traffic characteristics of the research object are analyzed,and a two-lane cellular automaton model is established for long and steep upgrade sections in extra long underwater tunnels.Secondly,Matlab is used to design simulation experiments to analyze the impact of different traffic capacity influencing factors.Finally,according to the main influencing factors of traffic capacity,the lane-dividing measure is proposed and the improvement effects and recommended conditions of it are analyzed,so as to provide substantive suggestions for opening up this traffic capacity bottleneck.The main research conclusions of this thesis are as follows.(1)To a certain extent,the capacity of extra long underwater tunnels decreases with the increase in slope,slope length,and the proportion of large vehicles,and increases first and then decreases with the increase in traffic volume,and slope and the number of large vehicles are the main influencing factors of traffic capacity.(2)The traffic capacity of extra long underwater tunnels after the implementation of the lane-dividing measure has been improved compared with that before the implementation,and the traffic capacity improvement effect is the best when the traffic volume reaches the forth service level and the proportion of large vehicles reaches about 30%.