The Research About The Design Of The Submerged Floating Reversed Suspended Cable Sea-crossing Bridge

There is 80 kilometers from east to west and 18 kilometers from south to north at the narrowest place in Qiongzhou Strait, which is the one of the three largest straits in China and only smaller than Bohai Strait and Taiwan Strait. The cross-sea channel of Qiongzhou Strait is very important, because it is not only the lifeline for the sustainable development of economy in Hainan province, but also the strategic passage to maintain the domain, airspace and mare clausum sovereignty of Nanhai Islands. The construction of the cross-sea channel is not only a problem in transportation field, but also involves the fields of energy sources, national defense, science and technology, opening to the outside world, comprehensive utilization, politics and economy, but also a very important project to strong our comprehensive national power and improve our economy in a great degree.At the beginning, the paper shows us some crossing sea projects in the world, including the built projects, the building projects and the planning to build project, such as the Tunnel of the English Channel, the sea-crossing bridge of Messina Strait, the cross-sea channel of Bering Strait, the crossing sea projects of Hangzhou gulf and the Qiongzhou Strait. We study the cross-sea channels including the sea-crossing bridge, the subsea tunnel and the Submerged floating tunnel by the introduction of the crossing sea projects. In order to overcome the drawbacks of the existing cross-sea channels, we conceive a new type of cross-sea channels—submerged floating reversed suspended cable sea-crossing bridge on the base of actual situation of Qiongzhou Strait. The advantages of the new bridge are having long single span(5000m), having no influence under harsh climate and having reliable stability, ect.The natural geographical environment of Qiongzhou Strait is deeply analysised on the base of widely referring all sorts of related documents. The content which has been researched includes the topography and geomorphology, the meteorology, the stratum, the geological structure of Qiongzhou Strait and the earthquakes and volcanos in this area. Then, some Schemes for crossing sea project of Qiongzhou Strait are introduced, they are the achievements for the many years'work of our country and make a good preparation for the new bridge.In the paper, the method and the theory of design of the new bridge have been researched, including the Superstructure and the substructure. In the design of the Superstructure, the section of the main girder, the bearings of the bridge, the connection of the girder section and the reversed cable system are researched; and then I have calculated and analysised the stress with the section of the main girder through the finite element software. It let us know the situation of the stress in the section in the finished stage, through which we can get conclusions that are very helpful to the design of the submerged floating reversed suspended cable sea-crossing bridge. In the design of the Substructure, by the comparison study of some types of the foundations which are widely used, the open caisson foundation, the pile foundation and the setting foundation are selected, also, we have make some design job for them. After the design, the construction of the new bridge has been discussed, it describes how to build the new bridge under our specific conditions and construction capability. Besides them, the design of the ventilation system and the lighting System, and the measures to fire protection and resuce have been researched referring to the design of long runnels. At last, the paper tells us the significance and the Emergency of the cross-sea channel of Qiongzhou Strait, it also tells us the new bridge is applicable for the cross-sea channel of Qiongzhou Strait.