Investigating mechanical characteristics of novel precast segmental lining using experimental and numerical methods

Abstract

In recent years, precast segmental lining (PSL) has attracted much attention in tunnel engineering. In practice, the segmentation method is an essential consideration for PSL. This study proposes a novel PSL with a specific steel space truss. It uses physical and numerical modeling and considers three different segmentation principles in the experiments. In addition, this research develops an accurate three-dimensional finite element model, enabling a detailed analysis of the novel PSL. It also investigates the influence of joint thickness and stiffener on the novel PSL. The experimental results indicated changes in the lining's displacement, internal force, and failure mode. They revealed that cracks initially appear at the block joints. Considering the force and deformation of the lining, the method based on the maximum moment position principle is optimal because it can achieve the lowest deformation and bending moments. The numerical results showed that increasing the joint thickness or welding stiffeners raises the bending stiffness, reduces the joint opening, and decreases the plastic zone and strain value, thereby improving the joints' reliability. The findings are advantageous for the tunnel PSL design and can serve as a reference for joint optimization.