Abstract: In recent years, with the rapid development of economy, urban rail transit also has accelerated the pace of speed increase, and various types of large diameter shield machines have been put into the construction of subway tunnels. Compared with the traditional shield machine, the large-diameter shield machine has the characteristics of large body, heavy self weight of formed ring, large disturbance to the stratum, and so on, which has a great impact on the stability of underground control points. The shield method is used to construct the tunnel at one time. The control wire in the tunnel is generally in the form of branch wire or ring wire, with large error accumulation. Especially for long distance tunnels, the measurement accuracy control is required to be higher. Therefore, in the construction of large-diameter shield long-distance tunnel, how to ensure the accurate penetration of the shield is a new test of the measurement control technology. Taking the first phase project of the new airport line of Beijing rail transit as an example, this paper briefly describes the control process and concerns of the survey work during the actual construction of the shield section of Beihang station building (excluding)-Cigezhuang (excluding), and focuses on the precision control of the contact survey and the precision control of each detail of the survey in the tunnel. It provides reference for improving measurement accuracy in long-distance construction of large diameter shield machine.

Key words: large diameter shield, long distance, control measurement, improve accuracy