Effect of Jack Thrust Angle Change on Mechanical Characteristics of Shield Tunnel Segmental Linings Considering Additional Constrained Boundaries

With the attitude adjustment of shield machine, jack thrust angle will change and may lead to great damage segmental lining structures. In this paper, a three-dimensional refined finite element method is proposed study action mechanism influence on mechanical characteristics tunnel, considering additional constrained boundaries formed by various construction loads. Firstly, established verified. Then, series analyses carried out investigate performance certain tunnel with eleven rings under conditions different angles. An in-depth discussion conducted obtained displacement, deformation, stress distribution. A quantitative standard finally gained for controlling angle. The results show that maximum segment displacement occurs at lower part arch waist second ring tail, which has little relationship adjustment. increase angle, offset between increases linearly, not conducive safety development direction opposite deflection. most affected deflection when machine upward, also unfavorable situation linings. in paper provide novel insights into effect tunnel.