Test And Theory Research On The Dynamic Characteristic Of Submerged Floating Reverse Suspended Cable Bridges

In order to connect the Highway Net of Hainan Province and that of the inland together, thus to improve the development Hainan society and economy, our country is programming and constructing the cross-sea alleyway project of Qiongzhou Strait actively. Submerged reverse suspended cable bridge is a new kind of bridge style, which combines suspended cable bridge with Archimedes Bridge. It contains both advantages of suspended cable bridge and Archimedes Bridge, it could be chosen as one of the implementary plans for the cross-sea alleyway project of Qiongzhou Strait. Submerged reverse suspended cable bridge is generally about 30m underwater in the sea; the environmental condition is very complicated. When there is resonant power generated by the outside environment which can cause resonance of the bridge body, it will bring a severe influence to the fabric intensity of submerged reverse suspended cable bridge, normal movement of the vehicles and the comfort of both drivers and passengers, etc. Therefore, it is necessary to research the interactional resonance between the submerged reverse suspended cable bridge and water and to realize the self-vibration frequency of submerged reverse suspended cable bridge under the dynamic condition.This article chooses the dynamic characteristic of submerged reverse suspended cable bridge as the researching object. At first, it introduces the concept and character of Archimedes Bridge, suspended cable bridge and submerged reverse suspended cable bridge, it expounds the research dynamics of Archimedes Bridge at home and abroad, it also demonstrates the advantages of the submerged reverse suspended cable bridge and the significance of this subject researching. Secondly, this article analyzes the environmental load's influence on the dynamic characteristic of submerged reverse suspended cable bridge; it explores the calculation methods of modal analysis in fluid-structure interaction system by applying ANSYS software. In order to study water's effect to the dynamic performance of deep-water pier, which is the submerged reverse suspended cable bridge's important part, this article uses two sets of test systems to carry on dynamic characteristic experiment of two groups of differently shaped pier models, to measure the self-vibration frequency of the models, thus to get the following conclusions. The interaction effect between piers and water formed in bridge's vibration process, with the increasing of water depth, self-vibration frequency decreases gradually while pier damp increases gradually, when water level reaches the certain height of the pier, water's effect to pier's self-vibration could not be neglected, etc. in order to design the model and experiment project of submerged reverse suspended cable bridge, this article adopts the simplified model of submerged reverse suspended cable bridge to carry on modal experiment in advance to test model's self-vibration frequency in different water levels, to research water level's effect extent to the dynamic characteristic of the simplified model of submerged reverse suspended cable bridge and to conclude experiment experience and rule, thus to lay the foundation of submerged reverse suspended cable cross-sea bridge's dynamic characteristic experiment. Finally, this article contains the dynamic characteristic model experiment of the 2m watertight cabin of submerged reverse suspended cable bridge and the whole system, it researches the vary rules of self-vibration frequency of vertical vibration and horizontal vibration of submerged reverse suspended cable cross-sea bridge's watertight cabin that varies from water level's change and different outside conditions, and gets many significant conclusions. Hope the research result of this article will provide some useful reference for future design and calculation in underwater suspended tunnel.