Investigation on shear performance of sliding-type rapid segmental joints for shield tunnels

Abstract

This paper introduces a sliding-type rapid joint and investigates the joint's failure modes under compression-shear loading with a combination of numerical and experimental methods. The study analyzes the influence of axial force, arrangement methods, and segment thickness on the joint's shear resistance. Additionally, a detailed examination of stress distribution within the joints provides a deeper understanding of their mechanical behavior. The results reveal that four-stage exists in the shear-dislocation curve of joints, including static frictional stage, partial sliding stage, overall sliding stage, and descending stage. Increasing axial force enhances the joint's shear resistance, but excessively high axial forces raise the risk of shear failure in T-shaped components. Under the trans-arrangement, the sliding-type rapid segmental joint exhibits superior shear resistance, especially under high axial loads. The material strength of C-shaped components impacts the joint's shear resistance, and increasing segment thickness enhances the joint's shear resistance. Under reverse-radial shear conditions, the structure's shear capacity is not solely determined by the joint strength. Tangential shear occurs during the assembly process, emphasizing the need to avoid excessive assembly forces. The junction between the T-shaped structure and the joint panel is a vulnerable point for T-shaped components, and reinforcement by increasing size and thickness can prevent shear failure at this location.