Mechanical analysis and design approach of composite segment for shield tunnel linings

The composite segment has been used in the deep, long, large, and multi-cross-section shield tunnels of the subway, underground road, underground pedestrian passage and underground reservoir, etc. However, the mechanical behavior of the composite segment is not clarified because the structural type is complicated. Meanwhile, the selected structure model and parameters are not reasonable. Therefore, the designed composite segment lining of a shield tunnel has disadvantages in terms of safety and economy. The stiffness reduction method is proposed for considering confined effect, interface slip, local buckling and damage. The proposed design method can be used to solve the coupling of multi-material and composite segment under multi-scale, and is suitable for a rational design of the composite segment because of improving the convergence of computations and having high precision and clear physical significance.