Behavioral Characteristics and Ovality of Shield TBM Tunnel Segment Lining Considering Break - Joint Mode

초록

This study analyzes the behavior characteristics of segmental linings by applying the Break-Joint Mode (BJM, Gharehdash and Barzegar, 2015), an analytical method that considers segmentation, as an interpretation method for segmental lining. The analysis results using this model show that the segments and rings cause relative displacements in discrete block units. The BJM relatively well simulates the deformation patterns of segmental linings constructed in soil grounds, particularly in soft ground. The study reviewed the stresses acting on segmental linings under static loads. The analysis results showed that under static loading, the stress values obtained from the BJM were lower across all sections of the segmental lining compared to those from the NJM. After the tunneling process is completed, shield TBM tunnel segmental linings exhibit ovality. Although each country has its own ovality quality standard in the range of 5‰ to 10‰, these standards are not based on structural analysis results. The existing standards are difficult to achieve for shield TBM tunnels installed in soil grounds. The Break-Joint Mode applied in this study presents a method to redefine ovality quality standards based on structural analysis.