Abstract:

The surrounding ground will be disturbed when a large diameter shield bores in curved section. In the paper, analysis is made on the influence of a superlarge diameter shield tunneling on the surrounding environment by means of site monitoring and FLAC 3D numerical simulation, so as to guarantee the safety of the construction and to provide a solution for the deformation difference. The monitoring items include ground surface settlement, layered settlement and deep horizontal displacement of soil. The study results show that: 1) The ground surface settlement takes place in 3 stages, i.e., when the cutting ring of the shield reaches, the rate of the ground surface settlement is low; when the shield passes, the rate of the ground surface settlement is high; when the shield tail passes, the rate of the ground surface settlement becomes stable; 2) The ground surface settlement on the inner side of the curved tunnel section is larger than that on the outer side of the curved tunnel section; 3) The horizontal displacement of ground on the inner side of the curved tunnel section is smaller than that on the outer side of the curved tunnel section.

Key words: Slender West Lake Crossing Tunnel, urved tunnel bored by largediameter shield, round surface settlement, ayered settlement, horizontal displacement