Research on Signal Transfer of GPR Used in Frontal Detecting of Tunnel Construction

At first, this paper discusses the unfavorable environment where a tunnel is constructed by shield machine. As a novel solution, GPR is employed to detect some undesirable obstacles or geological conditions to ensure a smooth tunnel construction. After a brief introduction about the implementation of the detecting system, this paper raises the problem about the signal transferring between the antenna and the GPR body, and between the GPR and the control computer, which are far away arranged each other in two different cabins with relative rotating motion and under a very difficult connection condition. Two signal transferring methods, by cable or by wireless, and their advantage and limitations are discussed. This paper then proposes some key mechanical and electrical modifications on the central swivel joint or some other assemblies of the shield machine to meet the requirement for the signal transferring of the GPR. As this GPR system is supposed to be long-term online detecting equipment, this paper provides a dedicatedly designed power supply to replace the original DC power of the GPR.