Influence of Bolt Arrangement on the Shear Performance of Circumferential Joints of Segments in Super-Large Cross-Section Shield Tunnels

To evaluate the shear performance of circumferential joints in super-large cross-section shield tunnels featuring inclined bolts and distributed mortises and tenons, refined numerical models were developed for three distinct configurations: single-bolt aligned mortise and tenon (SAB), single-bolt offset (SOB), and double-bolt offset (DOB). This study focuses on assessing how variations in bolt arrangement influence the shear behavior of these joints. The results are as follows: Under the effect of the ordinal shearing loading scenario (OSLS), bolts can significantly bear the load, resulting in the superior shear performance of DOB over SAB and SOB. Under the reverse shearing loading scenario (RSLS), bolts exhibit noticeable pullout phenomena, leading to minimal differences in the shear-dislocation curves of the three bolt arrangement pattern joints. The shear mechanical performance of SOB is notably better than that of SAB and SOB under OSLS, but this difference is less evident under RSLS. The mechanical behavior of bolts remains consistent across different bolt arrangement pattern joints during shear deformation. The bolt holes in SAB passing through the mortise and tenon weaken them, and contact failure between bolts and bolt holes further damages the mortise and tenon.