关键词: 超大直径盾构, 浅埋盾构隧道, 千斤顶推力, 衬砌管片, 结构内力, 变形

Abstract:  In order to study the structural force and deformation laws of shallowburied shield tunnel with super large diameter under different jack thrusts and deflections, a threedimensional model of shield tunnel lining segments considering water and soil pressure, shield tail brush reaction force, and jack thrust is established with finite element software ABAQUS. The internal force and deformation of lining segment are analyzed when the lining segment is deflected under the conditions of straight, upward, downward, and leftward movement of the shield. The results show that: (1) Jack thrusts mainly influence the first 8 rings of lining segment, in which the first 3 rings is more obvious, and the largest dislocation position in the ring is mainly concentrated near the capping; (2) The tunneling direction of shield mainly affects the displacement of the rings in this direction, instead of that in vertical direction; (3) The vault/bottom is mainly affected by vertical deflection angle and not affected by the lateral deflection angle, and the waist is more sensitive to lateral deflection angle and is less affected by vertical deflection angle; (4) When the vertical deflection angle occurs, the downward deflection angle is very easy to cause stress surge in the first few ring segments; (5) When the lateral deflection angle occurs, the ipsilateral deflection angle is more likely to cause displacement and stress surge in side segments.

Key words:  , super large diameter shield, shallowburied shield tunnel, jack thrust, lining segment, structural internal force, deformation