A Concrete-filled Steel Pipe Composite Segment for Shield Tunnel in Complex Geological Conditions

The traditional segment always experiences gradual performance degradation during its service life in complex geological conditions, which results in numerous problems in the form of large deformations, seepage, and concrete cracking. Therefore, a new type of composite segment was proposed, in which an arc-shaped concrete-filled steel pipe component is embedded. A numerical model of the proposed segment under three-point bending conditions was developed and subsequently validated through laboratory tests. A parametric study was also conducted, encompassing the dimensions and locations of the arc-shaped concrete-filled steel pipe component. The results indicate that the new composite segment can effectively enhance the segment’s load-bearing capacity, and both the yield and ultimate loads of the segment can be increased. Additionally, the parametric study revealed that the thickness and diameter of the pipe do not have a significant impact on the segment’s load-bearing capacity, and the position of the pipe does not affect the mechanical performance of the segment. The proposed segment can potentially be used to replace traditional segments in complex geological conditions. © 2024 School of Science, DUTH. All rights reserved.