Analysis On Breakthrough Accuracy Of Traversing For Immersed Tube Tunnel

The study of immersed tube tunnel in China appeared relatively late.Although more than 10 immersed tube tunnels have been successfully developed for recent decades in China,compared with some developed countries,the technology of the immersed tube tunnel is relatively backwardness in China.In the meantime,some domestic universities and research institutions have achieved results for the study of immersed tube tunnel.Also they have successfully completed a number of immersed tunnels.At present,there are few studies about the breakthrough measurement of large-scale immersed tube tunnels are conducted.However,breakthrough measurement of immersed tunnel plays an important role for not only the entire control system,but also the successful breakthrough of the tunnel.On the one hand,breakthrough measurement of the immersed tube section,it can be used to guide the sinking of the subsequent pipe section;on the other hand,for the immersed tunnel,the final joint model can only be obtained breakthrough measurement,and then the final joint can be prefabricated and installed to ensure that the whole immersed tunnel works smoothly.In this thesis,the breakthrough measurement of immersed tube tunnel is divided into two parts,the traversing inside the tunnel and the final joint measurement.For the traversing inside the tunnel,several feasible schemes are put forward first,which is followed by the analysis of some factors such as the precision of angle and side,the length of the traverse leg,the form of the traverse network and the gyro azimuth.Then,the influences of each factor on the transverse breakthrough precision of the immersed tube tunnel can be summarized.Finally,how to select the schemes of traversing inside the tunnel can satisfy the requirements of traverse breakthrough accuracy for different lengths of the immersed tube tunnels are given in this thesis.For the final joint measurement:the prefabricated final joint is mainly studied and analyzed.Firstly,four kinds of measuring methods for obtaining the final joint preform model parameters are presented,which are the method of conducting wire in the tunnel,the measuring tower,the 3D laser scanning method and the acoustic method;Then the principle and process of each method are described,and the measurement accuracy is analyzed;Finally,the advantages and disadvantages of each method are summarized,which can provide reference for engineering practice.Firstly,this thesis introduces the history and technology development of immersed tube tunnel,and the research status quo of the immersed tunnel measurement and penetration measurement at home and abroad;Then,through the study of the actual project,this thesis summarizes the construction of the tunnel during the construction of the required measurement work,and each link measurement principles and methods are described;Then,the precision of the traverse measurement is discussed;Finally,the test data processing program is designed to meet the requirements of the experiment.Through the study of this thesis,it can not only provide a reference for the researchers to learn the knowledge of the immersed tube tunnel,but also provide reference for the construction personnel to make the technique scheme of the breakthrough measurement for the immersed tube tunnel.Besides,the study of this thesis will help the research on the breakthrough measurement of the immersed tunnel in the future.