Abstract:

A shieldbored running tunnel of Hangzhou Metro is studied in the paper. 3D models are established for the case of normal shield posture and for the case of floatingupward shield posture, and the ground surface settlement induced by the shield tunneling is calculated on basis of different ground loss ratios in different cases. The calculation results are compared with the measured data, and are verified by the results calculated by Peck formula. Conclusion is drawn that the ground loss ratio in the case of floatingupward shield posture is 1.9% and that in the case of normal shield posture is 1%. The paper can provide reference for the prediction of the ground surface deformation induced by shield tunneling in Hangzhou and other cities.

Key words: shieldbored tunnel, floatingupward posture, ground surface settlement prediction, ground loss ratio