Abstract:

The rationality of shield type selection and the accuracy of the shield parameters are key factors to ensure the success of shieldbored tunnels. In this paper, the geological and hydrological characteristics of South Railway StationShenxianshu Station section on Line 7 of Chengdu Metro are presented, the adaptability of different types of shields to different strata is discussed, and the feasibility and necessity of EPB shield for the project are expounded. Furthermore, the selection of each system of the shield is analyzed. The calculated maximum thrust of the shield machine is 10 659 kN, and the calculated maximum torque of the cutter head is 4 072 kN•m; the proposed maximum thrust of the shield machine is 26 648 kN, and the proposed maximum torque of the cutter head is 6 108 kN•m. Finally, comparison and contrast is made between the calculated values and the measured values, which proves that the theoretical calculation of the thrust of the shield machine and the torque of the cutter head is accurate.

Key words: Chengdu Metro, sandy pebble strata, shield type selection, thrust, cutter head driving torque