Research Of The Immersed Tube Tunnel Surveying System

Method of immersed tube tunnel construction, it is the prior preformed sections setting control section in the water has been well excavation base trough, again will each day in the water pipe joint for butt joint and assembling, finally together as a whole a tunnel construction method.And in the process of the whole immersed tube tunnel construction, pipe joint precision underwater docking is extremely important, currently on the underwater positioning control section measurement methods mainly include method of total station, RTK GPS, sonar, and four basic measuring methods, such as mechanical drawing method.But with the application of the method of immersed tube tunnel construction is becoming more and more widely, the construction of immersed tube tunnel environment is more and more complex, the scale of the sinking tube section is more and more big, but only an immersed tube measurement method will be difficult to meet the requirements of sinking under the control of water-saving accurate positioning.Immersed tube tunnel engineering of the Hong Kong, zhuhai and macau bridge under the condition of underwater for more than 20 m depth, the construction of 5664 m, a total of 33 socket immersed tube tunnel in the world for the first time, and the construction of regional geography, weather, hydrology condition is complex, immersed tube sinking put high measurement accuracy requirements, is currently the world’s one of the most difficult immersed tube tunnel.In this paper, by constructing mathematical model, combining with the construction survey, focus on research and analysis of two methods of positioning method of GPS RTK- and sonar and the theoretical basis of the advantages and disadvantages, puts forward the method of sonar and RTK GPS method combined positioning method in the application of large sink under the control of water-saving positioning.Taking hong kong-zhuhai-macao immersed tube tunnel project as an example, introduced and analyzed in this paper using sonar method and RTK GPS positioning method of pipe joint of the immersed tube tunnel measurement and control system of underwater positioning effective application, solved the accurate docking large immersed tube in the deep waters off the coast.