Abstract: The construction risks in the launching stage of superlarge slurry balance shield should be controlled. As a result, the steel sleeve used in launching of a superlarge air cushion slurry pressure balance shield with a diameter of 12.16 m of the Canapuri River Tunnel Project in Bangladesh of BangladeshChinaIndiaMyanmar Economic Corridor of "the Belt and Road" is designed in sections considering the local hoisting resources and the limitation of ocean shipping. Before the shield breaks the retaining structure behind the tunnel portal in the sleeve, it is necessary to strictly control the driving torque of the shield to avoid the whole torsion of the shield body and the steel sleeve. The torsional resistance of the steel sleeve of the shield during the launching construction is analyzed by using finite element simulation technology. The results show that: (1) The steel sleeve can meet the resistance torque required for shield launching. (2) The maximum stress of the steel sleeve, the maximum displacement, the maximum horizontal displacement and the maximum vertical displacement are 16.6 MPa, 0.52 mm, 0.02 mm and 0.51 mm, respectively, which satisfies the checking conditions of the stress and deformation of the initial steel sleeve of shield tunneling. The corresponding antitorsion measures for steel sleeve launching of superlarge diameter shield are formulated based on the simulation results.

Key words: subsea tunnel, slurry balance shield, shield launching, steel sleeve, finite element analysis, torsion resistance