Simulation Analysis And Test Research Of Submerged Floating And Reverse Suspension Sea-crossing Bridge

The sea-crossing project of Qiongzhou Strait plays an important role in both the national highway network and the regional transportation planning.In all the conventional programs the experts proposed,there is a problem that the project cost and transportation cost increase rapidly as the increasing of the crossing width and crossing depth.The submerged floating and reverse suspension sea-crossing bridge becomes a better choice for it does not exist this problem.The submerged floating and reverse suspension sea-crossing bridge is a new bridge structure constructed in this paper which based on submerged floating tunnel and suspension bridges,its structure form is:the base is common foundation and cap, reverse suspension system is upon the cap,the main beam is the watertight compartment whose location is under water about twenty meters,and the watertight compartment is upon the inverse suspension system.This paper chooses the dynamic characteristics of the submerged floating and reverse suspension sea-crossing bridge to be the researching object,and chooses the experiment and finite element analysis as the major study methods.At first,it introduces the concept,characters,the domestic and international research developments and research achievements of the submerged floating tunnel, and also picks out the advantages of the submerged floating and reverse suspension sea-crossing bridge as well as the significance of this research subject.Secondly,this paper analyses the environmental loads that the submerged floating and reverse suspension sea-crossing bridge suffers,and mainly introduces the effects and influences of the wave load,current load and earthquake load.Then this paper discusses the fluid-structure interaction question in the submerged floating and reverse suspension sea-crossing bridge,and investigates the calculating method of using the finite element software ANSYS to analyze the modes of the fluid-structure interaction system,two examples are also presented to verify the calculating method. After that,this paper carries out the modal tests of the pier foundation of the submerged floating and inverse suspension sea-crossing bridge both in air and in water,and also compares the test results with the results that former calculated with the finite element software ANSYS,the results of the two are all in line,it shows that both the test method and the calculating method are feasible.And then,this paper conducts the dynamic characteristic modal experiments of the watertight compartment and the whole system of the 2m long submerged floating and reverse suspension sea-crossing bridge,and researches the self-vibration frequencies of vertical vibration and horizontal vibration of submerged floating and reverse suspension sea-crossing bridge's watertight compartment that varies from different water depth and different boundary conditions.Then,the cross-sectional size of the watertight compartment,the main cable size and the suspender size of the submerged floating and reverse suspension sea-crossing bridge are designed in this paper,finite element model is constructed, and the simulation analysis in different conditions is also done.The modal analysis about the model is done at the same time.Finally,this paper summarizes the research conclusions and achievements,and also points out the questions exist in the paper,suggestions about the following research of the submerged floating and inverse suspension sea-crossing bridge are given as well.Hope the work of this paper could do some help to the following researches of the new bridge.